# Microbial production of biopesticides for sustainable agriculture

Madan Lal Verma, Ashutosh Kumar, Anjani Devi Chintagunta, Prashant

Jeevan Kumar Samudrala, Marc Bardin, Eric Lichtfouse

► To cite this version:

Madan Lal Verma, Ashutosh Kumar, Anjani Devi Chintagunta, Prashant Jeevan Kumar Samudrala, Marc Bardin, et al.. Microbial production of biopesticides for sustainable agriculture. Sustainability, 2024, 16, pp.7496. 10.3390/su16177496. [https://hal.science/hal-04688839v1](https://hal.science/hal-04688839v1)

HAL Id: hal-04688839

Submitted on 5 Sep 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Microbial Production of Biopesticides for Sustainable Agriculture

Madan Lal Verma <fnref n="1" />*, Ashutosh Kumar <fnref n="2" />, Anjani Devi Chintagunta <fnref n="3" />, Prashant Jeevan Kumar Samudrala <fnref n="2" />,<fnref n="4" />, Marc Bardin <fnref n="5" /> and Eric Lichtfouse <fnref n="6" />

**Abstract:** Food security is threatened by biotic stress on crops, e.g., from invasive pests, in the context of climate change. Pest control has traditionally been achieved using synthetic pesticides, yet pollution and the persistence and toxicity of some pesticides are inducing food contamination and, in turn, generating public concern. As a consequence, biopesticides are increasingly used, notably for organic crops. For instance, some microorganisms produce biopesticidal compounds such as secondary metabolites or growth-inhibitory enzymes. Most reviews on this topic mainly focus on describing microbial species and their active compounds. However, there are very few studies and reviews describing various process parameters. Here, we review both microbial biopesticides and factors controlling physicochemical conditions for the scaling up of biopesticide production. We present biopesticides from bacteria (e.g., *Bacillus thuringiensis*), algae, fungi, and viruses and review the biocontrol mechanisms and applications of commercial biopesticides. The benefits of genetic engineering for enhancing activity and drawbacks such as commercialization are also discussed.

**Keywords:** agriculture; biocontrol; biopesticides; microbes; strain improvement; sustainability

## 1. Introduction

The global population is projected to reach 9.7 billion in 2050 and may reach around 11 billion by the end of the 21st century [1]. This surge in population, dwindling natural resources (due to the exploitation of forests), and the increase in biotic and abiotic stresses due to climatic change impede food and nutritional security. Biotic stress in crops is mainly caused by several insects and phytopathogens such as arachnids, bacteria, fungi, nematodes, viruses, and weeds [2–4]. Crop productivity has been ensured through the application of synthetic pesticides to save crops from pest damage. However, the injudicious use of synthetic pesticides in crop production has resulted in the increased resistance of pests against synthetic pesticides. Moreover, higher pesticide usage affects soil health, wildlife habitats, and water quality and increases health risks for farm workers, farmers, rural populations, and consumers [5–8]. Considering the repercussions of synthetic pesticides, the development of biopesticides derived from microbes and their products can be a viable alternative for plant protection [9,10]. Emerging evidence corroborates that biopesticides have been playing a promising role in controlling common insect pests and phytopathogens, and they are also species-specific, eco-friendly, and cost-effective in nature.

Biopesticides can be defined as bio-based substances, derived from bacteria, entomopathogenic fungi, plants, nematodes, and viruses, acting against crop pests with differ-

<footnote n="1">¹ Department of Biotechnology, School of Basic Sciences, Indian Institute of Information Technology Una, Una 177209, Himachal Pradesh, India</footnote>

<footnote n="2">² ICAR-Indian Institute of Seed Science, Kushmaur, Mau 275103, Uttar Pradesh, India; ashu.nbaim@gmail.com (A.K.); jeevan.kumar@icar.gov.in (P.J.K.S.)</footnote>

<footnote n="3">³ Vignan Foundation for Science, Technology and Research, Vadlamudi, Guntur 522213, Andhra Pradesh, India; ad3_res@vignan.ac.in</footnote>

<footnote n="4">⁴ ICAR-Directorate of Floricultural Research Institute, Pune 411036, Maharashtra, India</footnote>

<footnote n="5">⁵ INRAE, Pathologie Végétale, Montfavet, 84140 Avignon, France; marc.bardin@inrae.fr</footnote>

<footnote n="6">⁶ State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049, China; eric.lichtfouse@icloud.com</footnote>

<footnote>* Correspondence: madanverma@iitu.ac.in or madanverma@gmail.com</footnote>
ent mechanisms of action [11,12]. Biopesticides, compared to synthetic pesticides, have advantages such as being environmentally benign and free of harmful residues, not provoking chemical resistance development in pests, having low-cost production, and being easy to use [13]. Biopesticides coupled with integrated pest management (IPM) can be employed for increasing sustainable agricultural productivity [14]. Microbial species isolated from rhizospheric soil and different ecological niches, such as *Trichoderma viride* [2], *Metarhizium anisopliae* [15,16], *Beauveria bassiana* [17], nuclear polyhedrosis virus [18,19], *Pseudomonas* spp. [20], *Bacillus thuringiensis* [21,22], *B. subtilis*, *B. licheniformis*, *B. amyloliquefaciens*, *B. velezensis*, *B. firmus*, and *B. nakamurai* [23,24], demonstrated the ability to protect navel seedlings from pests [25,26]. Therefore, owing to their potential in controlling pests, these microbes could be utilized for the production of different biopesticides.

In the current scenario, biopesticides are highly used in horticulture and vegetable cultivation but have a marginal reach in staple food production compared to synthetic pesticides [27–29]. Currently, the biopesticide market covers nearly 8% of the total plant-protecting products [30], and around 700 different microbe-based products have been registered globally. Mishra et al. [31] have reported that within the biopesticide market for all crop types, bacterial biopesticides (74%) are predominant in the global market, while fungal biopesticides account for 10%, viral biopesticides constitute 5%, and other biopesticides make up 11% (Figure 1). Generally, the non-microbe-based biopesticides are synthesized via the incorporation of beneficial biological entities and/or their derivatives, which protect plants from their predators. For instance, in organic coconut production, *Neoseiulus baraki* coupled with azadirachtin has been used to control the invasive coconut mite *Aceria guerreronis* [32].

<figure><img src="image_2.png" /><figcaption>**Figure 1.** Share percentages of different groups of biopesticides in the global market. Bacterial biopesticides account for 74% of the share of the gross biopesticide market and production around the world, followed by 10% for fungal biopesticides, and non-microbial-based biopesticides account for only 11% of the global market regarding pesticide production.</figcaption></figure>

The US Environmental Protection Agency (USEPA) has predicted a global hike in the biopesticide market from USD 4.3 billion to USD 8.5 billion by 2025, which indicates the growing trend of biopesticide application around the world [33–35]. Despite the fact that a large number of biopesticides have been marketed, there are still limitations that impede the development of biopesticides for widespread use in agriculture. Although several microbial
strains have exhibited potential biocontrol properties and other beneficial traits, this often does not translate into effective, consistent, and repetitive action as biocontrol agents in diverse field conditions. There might be several reasons for non-effective functioning of biopesticides with desirable beneficial traits, including environmental stresses, specific nutrient requirements, and the poor genetic expression of beneficial traits (secretion of metabolites) under field conditions. Thus, integrated applications of recombinant DNA technology along with biochemical engineering can be employed for the manipulation of specific genes' expression to enhance the production of beneficial compounds. Similarly, metabolic engineering pertinent to strain improvement could result in higher biomass and product recovery from marginal-potential microbial strains.

In the last two decades, biopesticide applications have gained immense attention in agriculture, and recent updates need to be compiled to emphasize the effective implementation of biopesticides in agriculture [36,37]. Thus, the current review shows the significance of using biopesticides in agriculture and the recent progress achieved in biopesticide production over the past few decades. This review covers recent advances pertinent to nutrient requirements for the enhanced biomass production of biocontrol agents, development of low-cost media for growth and cultivation, optimization of physiological conditions for increased biomass production and processes for higher end-product recovery. The current review critically summarizes different modes of biocontrol activities of potential biocontrol agents and information pertinent to recent strains improvement used for biopesticide synthesis. Simultaneously, constraints encountered for the commercialization of biopesticides from different strains have been elucidated.

## 2. Common Pests and Prospective Biopesticides

Some common insects and phytopathogens that reduce crop productivity in major crops are *Magnaporthe oryzae* [38], *Fusarium* spp. [39], *Rhizoctonia solani* [40], *Alternaria* spp. [41], *Aspergillus* spp. [42], *Conopomorpha sinensis* [43], *Eudocima* spp. [44] and *Aceria litchii* [45], *Plutella xylostella* [46,47] *Spodoptera frugiperda* [48,49], *Tuta absoluta* [50], and *Schistocerca gregaria* [51,52], of which their impact on crop productivity has been illustrated in Table 1. According to studies, the *Plutella xylostella* has been considered a highly destructive pest to cabbage, broccoli, and cauliflower as the pest has potential to cause crop destruction of up to 70–90% [46,47]. Similarly, *Tuta absoluta*, a common pest known as tomato pinworm, could completely deteriorate the tomato crop [50,53]. To arrest the growth of the pests, synthetic pesticides have been widely used. However, owing to the deleterious nature of synthetic pesticides on soil and the environment, crop protection from phytopathogens, insects, and weeds through biopesticides has been gradually gaining interest [54,55].

<table><caption>**Table 1.** Common insects and phytopathogens and their impact on different crops.</caption><thead><tr><td>Pests</td><td>Crop Affected</td><td>Estimated Loss</td><td>Reference</td></tr></thead><tbody><tr><td>Fruit borers<br/>Conopomorpha sinensis,<br/>C. litchiella</td><td>Rambutan (Nephelium lappaceum),<br/>Cocoa (Theobroma cacao), litchi (Litchi<br/>chinensis Sonn.)</td><td>48–74% loss in West Bengal<br/>and Bihar, India</td><td>[43,56]</td></tr><tr><td>Fruit-piercing moths<br/>Eudocima phalonia, Eudocimasalaminia<br/>and Eudoci majordani</td><td>Coral tree, Erythrina crista-galli,<br/>Erythrina fusca, Carronia multisepala,<br/>Legnephora moorei, Hypserpade cumbens,<br/>Sarcopetalum harveyanum, Stephania<br/>forsteri, Tinospora smilacina</td><td>10–55% loss in India, 20–30%<br/>in China, and 95% in New<br/>Caledonia</td><td>[44,57]</td></tr></tbody></table>
<table><caption>Table 1. *Cont.*</caption><thead><tr><th>Pests</th><th>Crop Affected</th><th>Estimated Loss</th><th>Reference</th></tr></thead><tbody><tr><td>Leaf-feeding caterpillars</td><td></td><td></td><td></td></tr><tr><td>Oxyodes scrobiculata, Oxyodes tricolor, Gonimbrasia belina Westwood, Achaea janata</td><td>Mostly castor bean and crotons but occasionally cabbage, Chinese cabbage, Banana, crown of thorns, mustard, ficus, sugarcane, poinsettia, tomato, rose, legumes, and Brassica species</td><td>45.4% in India</td><td>[58,59]</td></tr><tr><td>Leaf rollers Olethreute serrulata, Platypeplus aprobola, Adoxophyces cyrtosema, Homona coffearia, Homona difficilis, Isotones smiserana</td><td>Lychee, longan, and rambutan</td><td>22% in India</td><td>[60]</td></tr><tr><td>Beetle borers Aristobia testudo, Anoplophora maculata, Uracanthus cryptophagus</td><td>Litchi and guava</td><td>10-48% in Bangladesh</td><td>[61]</td></tr><tr><td>Scarab beetles</td><td></td><td></td><td></td></tr><tr><td>Pulvinaria psidii</td><td>Maize, potato, wheat, barley, bajra, jawar, sunflower groundnut, sesame, chillies, cotton, tobacco, sugarcane, cucurbit, brinjal, and okra</td><td>12-60% Nepal</td><td>[62-64]</td></tr><tr><td>Soft scales Pulvinaria psidii</td><td>Citrus fruits</td><td>30-40% in California</td><td>[65,66]</td></tr><tr><td>Bugs Tessaratoma papillosa, Tessaratom ajavanica, Tessaratoma quadrata</td><td>Litchi, apple, and pear</td><td>>80% loss in Australia, China, Myanmar, Thailand, and Jharkhand</td><td>[67,68]</td></tr><tr><td>Mites Aceria litchii, Agistemus exsertus, Polyphagotarsonemus latus</td><td>Litchi</td><td>50% in Sri Lanka</td><td>[45]</td></tr><tr><td>Gall flies Dasineura sp., Litchi chinensis</td><td>Eucalyptus spp., Banksia spp., Acacia spp.</td><td>30-40% in Sri Lanka</td><td>[23]</td></tr><tr><td>Fruit flies Bactrocera tryoni, Ceratitis rosa</td><td>Apples, berries, citrus, capsicum, summer fruit, pears, loquats, olives, grapes, eggplant, persimmons, tomatoes, and mangoes</td><td>25% in Italy, 30-35% in Greece, 20-40% in Yugoslavia, 20-60% in Israel, and 15-20% in Cyprus</td><td>[69]</td></tr><tr><td>Plant Pathogens Botrytis cinerea</td><td>Fruit crops</td><td>10-15% reduction in fruit crop 20% reduction crop production in wheat in the world</td><td>[70,71]</td></tr><tr><td>Puccinia spp.</td><td>Cereal crops</td><td>15-20% in wide range of crops around the world</td><td>[72]</td></tr><tr><td>Colletotrichum spp.</td><td>Horticultural crops</td><td>5-20% in tomato, cowpea and pepper in the world</td><td>[73,74]</td></tr><tr><td>Sclerotium rolfsii, Athelia rolfsii</td><td>Vegetable and fruit crops</td><td>5-15% reduction in tomato around the world</td><td>[75,76]</td></tr><tr><td>Sclerotinia sclerotiorum</td><td>Vegetable crops</td><td>5-17% vegetable reduction</td><td>[77,78]</td></tr><tr><td>Pythium spp.</td><td>Vegetable and fruit crops</td><td>70-90% yield loss</td><td>[79,80]</td></tr><tr><td>Plutella xylostella</td><td>Brassicaceous crops (cabbage, broccoli, and cauliflower)</td><td>40-47% yield loss</td><td>[49,81-83]</td></tr><tr><td>Spodoptera frugiperda (Fall armyworm)</td><td>Maize, sorghum</td><td>80-100% yield loss</td><td>[50,84]</td></tr><tr><td>Tuta absoluta (South American tomato pinworm)</td><td>Tomato</td><td>80-100% yield loss</td><td>[51]</td></tr><tr><td>Schistocerca gregaria (Desert locust)</td><td>Wide range of crops, mainly cereals</td><td>80-100% yield loss</td><td>[51]</td></tr></tbody></table>
Some of the prominent biopesticides playing a pivotal role in the global biopesticide market are predominantly from *B. thuringiensis*, *Trichoderma* spp., *B. bassiana*, and *Pseudomonads*. The bacterium *B. thuringiensis* has been reported for insect control and covers around 2% of the total insecticidal market [85,86] and around 90% of bacterial biopesticides market [36]. Its insecticidal properties are also extended to genetically modified products like Bt cotton. Fungi, *Trichoderma harzianum*, and *T. viride*, are the most popular biocontrol representatives in use to oppose various plant pathogens [2,86]. *Trichoderma* spp. developed complex interaction with host plants and rhizospheric microbial communities, performed antibiosis, and induced systemic resistance in plants to oppose crop pests [86,87]. Further, *Pseudomonads* are extensively used for biopesticide production due to the secretion of secondary metabolites like 2,4-diacetylphloroglucinol, cyclic lipopeptides, phenazines, pyoluteorin, pyrrolnitrin, and hydrogen cyanide [54]. These compounds show antagonistic potential against pests, which implies biopesticidal activity [2,87].

### 3. Optimization of Process Parameters for Biopesticide Production

The process of biopesticide synthesis consists of various steps, such as isolating microorganisms from different natural habitats, species purification, and screening for biocontrol activity against various pathogens. To maximize the potential of promising microbes, process optimization is a preliminary step in biopesticides production. Parameters such as nutrient and physical (pH and temperature), inoculum volume and age, and inducers are essential, particularly for the large-scale production of either secondary metabolites or enzymes [88–90]. On the other hand, for the intracellular multiplication of compounds, the optimization of extraction with a suitable solvent system would be another step in the downstream process. The secretion of specific compounds and lytic enzymes from potential microbes can be altered through the variation in physical factors (pH, temperature, humidity, and pressure) and nutritional conditions [53,54,91]. Some studies on the optimization of physicochemical are illustrated in Table 2. Biopesticides production is influenced by physicochemical conditions for the scale-up of biopesticides production, and understanding the role of influential parameters such as temperature, carbon and nitrogen sources, aeration, and pH results in a better production of biopesticides [92–94].

<table><caption>**Table 2.** Microbial species involved in biopesticide production.</caption><thead><tr><th>Microbial Species</th><th>Type</th><th>Target Pest</th><th>References</th></tr></thead><tbody><tr><td>Bacteria</td><td></td><td></td><td></td></tr><tr><td><i>Bacillus popilliae</i></td><td>Insecticide</td><td><i>Popilla japonica</i></td><td></td></tr><tr><td><i>Burkholderia cepacia</i></td><td>Fungicide</td><td>Soil-borne fungi, nematodes</td><td></td></tr><tr><td><i>Pseudomonas fluorescens</i></td><td>Fungicide</td><td>Soil-borne fungi and frost damage, fire blight<br>(<i>E. amylovora</i>)</td><td></td></tr><tr><td><i>P. syringae</i></td><td>Fungicide</td><td>Post-harvest fungi</td><td></td></tr><tr><td><i>P. chlororaphis</i></td><td>Fungicide</td><td>Soil-borne fungi</td><td></td></tr><tr><td><i>P. aureofaciens</i></td><td>Fungicide</td><td>Soil-borne fungi</td><td>[95–104]</td></tr><tr><td><i>Bacillus subtilis</i></td><td>Fungicide</td><td>Soil-borne fungi</td><td></td></tr><tr><td><i>Streptomycin griseoviridis</i></td><td>Fungicide</td><td>Soil-borne fungi</td><td></td></tr><tr><td><i>Streptomyces lydicus</i></td><td>Fungicide</td><td>Soil-borne fungi</td><td></td></tr><tr><td><i>Agrobacterium radiobacter</i></td><td>Bactericide</td><td>Crown gall <i>A. tumefaciens</i></td><td></td></tr><tr><td><i>Xanthomonas campestris pv. Poae</i></td><td>Herbicide</td><td><i>Poa annua</i></td><td></td></tr><tr><td><i>Pseudomonas syringae pv. Tagetis</i></td><td>Herbicide</td><td><i>Cirsium arvense</i></td><td></td></tr><tr><td><i>Ralstonia solanacearum</i></td><td>Bactericide</td><td>Pathogenic <i>R. solanacearum</i></td><td></td></tr><tr><td>non-pathogenic</td><td></td><td></td><td></td></tr></tbody></table>
<table><caption>Table 2. *Cont.*</caption><thead><tr><th>Microbial Species</th><th>Type</th><th>Target Pest</th><th>References</th></tr></thead><tbody><tr><td>Fungi</td><td></td><td></td><td></td></tr><tr><td>Alternaria cassia</td><td>Insecticide</td><td>Sickle pod (weed)</td><td></td></tr><tr><td>Aschersonia</td><td>Insecticide</td><td>Aleyrodide whitefly</td><td></td></tr><tr><td>Beauveria bassiana</td><td>Insecticide</td><td>Cotton bollworms, coffee berry borer, codling moth, Japanese beetle, pod borer, cotton leaf hopper, chinch bug, Northern joint vetch (weed)</td><td>[95–109]</td></tr><tr><td>Colletotrichum gloeosporioides</td><td>Insecticide</td><td>Velvet leaf</td><td></td></tr><tr><td>Fusarium lateritium</td><td>Insecticide</td><td>Phytophagous mites</td><td></td></tr><tr><td>Hirsutella thompsonii</td><td>Insecticide</td><td>Rhinoceros beetle, spittlebug, grasshoppers, sugarcane hopper, locust, termite</td><td></td></tr><tr><td>Metarhizium anisopliae</td><td>Insecticide</td><td>Helicoverpa armigera, Spodoptera litura, Trichoplusia ni and Achaeta Janata</td><td></td></tr><tr><td>Nomuraea rileyi</td><td>Insecticide</td><td>Milkweed vine</td><td></td></tr><tr><td>Phytophthora palmivora</td><td>Insecticide</td><td>Green leaf hopper of rice and Brown plant hopper</td><td></td></tr><tr><td>Pandora delphacis</td><td>Insecticide</td><td>Aphid, whiteflies, and scales</td><td></td></tr><tr><td>Verticillium lecanii</td><td>Insecticide</td><td></td><td></td></tr><tr><td>Viruses</td><td></td><td></td><td></td></tr><tr><td>Acoviruses, Baculoviruses, Granuloviruses, Iridoviruses, Nucleopolyhedrosis viruses, Poxviruses, Parvoviruses</td><td>Insecticide</td><td>Cabbage moths, beet armyworms, corn earworms, celery loopers, cotton leaf worms, bollworms, and tobacco budworms</td><td>[95,110–113]</td></tr></tbody></table>

### 3.1. Carbon-Nitrogen Sources in Biopesticide Production

B. thuringiensis-based biopesticides comprise a 70–74% share in biopesticide production around the world, which are practiced in integrated pest management [114,115]. Research has been performed to optimize and develop a cost-effective procedure for the production and recovery of insecticidal delta-endotoxin from B. thuringiensis by feeding regimes [68–72,116–120]. B. thuringiensis secretes crystal (Cry) proteins, an endotoxin that potentially inhibits the growth of coleopteran, lepidopteran, and dipteran insects [121]. The production and expression of Cry proteins are associated with the sporulation of B. thuringiensis [122]. Vu [117], Boniolo [118], Devidas [119], and Lormendez [123] have reported a higher production of Cry protein (delta-endotoxin) through continuous fed-batch processes from B. thuringiensis. In the log phase, B. thuringiensis utilizes glucose as a carbon source and other nutrients for biomass synthesis. Upon reaching the stationary phase, bacterium sporulates and, as a result, Cry toxin is secreted. Lormendez [123] has reported that carbon sources in the medium play a crucial role in bacterial sporulation and production of Cry proteins. Amin [116] used two different glucose concentrations—lower (10–20 g/L) and higher (50–90 g/L)—for B. thuringiensis-based biopesticide production and reported that the lower dose of glucose was more effective in producing higher levels of Bt toxin due to the early stationary phase. Brar [124], Hung [125], and Pacheco [126] have revealed that the crystal protein of B. thuringiensis is predominantly available at higher levels (25%) during sporulated cellular dry mass conditions. Masri and Ariff [127] evaluated the result of the batch and fed-batch process on the cellular growth of B. thuringiensis. Noticeably, a higher viable cell count (>1.5×10¹² CFU/mL) was observed in the fed-batch mode compared to the batch mode (1.4×10¹² CFU/mL). Thus, it can be concluded from the above-discussed bioprocessing studies of B. thuringiensis that a lower concentration of glucose promotes sporulation and higher production of Cry proteins.

Wafa [36] reported important carbon sources such as cellulose, fructose, glucose, maltose, trehalose, ribose, starch, and xylan for biopesticide production from B. thuringiensis. Excessive glucose supplementation enhanced cellular growth but ceased sporulation and toxin production due to the inhibition of SpoA (sporulation-related protein) activity in the B. thuringiensis. For instance, B. thuringiensis var. galleriae showed higher biomass production at a glucose concentration of 28 g/L, but a glucose concentration near 35 g/L in the
production medium resulted in reduced biomass production [34]. The biomass production of *B. thuringiensis* var. *israelensis* was inhibited when cultivated with a glucose concentration of 75 g/L [128]. In a similar study, Amin [116] confirmed the growth inhibition of *B. thuringiensis* var. *kurstaki* at higher glucose concentrations (50 and 90 g/L). All these studies indicate that a glucose concentration of 23 g/L is optimal for *B. thuringiensis*-based biopesticide production. Sadek [129] reported that the presence of essential amino acids, such as aspartate glutamate, leucine, serine, threonine, and valine in the medium for the growth, sporulation, and toxin formation of *B. thuringiensis*. However, the amino acid cysteine inhibits the growth and sporulation of *B. thuringiensis*. The optimum initial pH of the growth medium used for cultivating *B. thuringiensis* should be between 5.5 and 8, while the appropriate carbon-to-nitrogen ratio is 7.5 [36]. Various metal ions, such as calcium, copper, iron, manganese, magnesium, potassium, and zinc are essentially required for the proper sporulation and delta-endotoxin formation.

One of the pseudomonads, *Pseudomonas chlororaphis*, secretes biopesticidal compounds, including phenazines, volatile hydrogen cyanide, and pyoverdine-type iron-chelating siderophores, against plant pathogens [130,131]. *P. chlororaphis* secretes proteins (*fitD* protein) that are virulent to insects through mouth feeding. The infection mediated by *P. chlororaphis* isolate PCL1391 caused the death of the fall army worms (*Spodoptera frugiperda*) and *Heliothis virescens* larvae [132]. Studies indicate that pseudomonads proliferate on glycerol (1.5%) and peptone (2%) ingredients [133–135]. DeBritto [136] supplemented individual soybean, watermelon, groundnut, corn, and sweet potato broths along with peptone (nitrogen source) for increased pyocyanin production in *Pseudomonas aeruginosa* KU BIO2. It was reported that soybean broth coupled with peptone resulted in increased pyocyanin production (1702 mg/L).

Besides bacteria, several strains of entomopathogenic fungi are engaged in the biological control of plants against pests. Entomopathogenic fungi are parasitic microbes with the potential to kill arthropods [137]. Among the fungal strains, the genus *Trichoderma* is an imperfect saprophytic filamentous fungus with fungicidal behavior towards several pathogens that are being applied as a mycobiopesticide [138]. Similarly, *Coniothyrium mini-tans* has fungicidal activity against *Sclerotinia sclerotiorum* [139]. The fungus *Paecilomyces lilacinus* acts as a nematicide that is used against the secretion of lytic enzymes such as chitinases and proteases [140]. Entomopathogenic fungi such as *Alternaria cassia*, *Ascherso-nia aleyrodis*, *Beauveria bassiana*, *Colletotrichum gloeosporioides*, *Fusarium lateritium*, *Hirsutella thompsonii*, *Metarhizium anisopliae*, *Nomuraea rileyi*, *Pandora delphacis*, *Phytophthora palmivora*, and *Verticillium lecanii* have biopesticidal activities against several pests [26,141,142].

*Beauveria bassiana* is another fungus that has been extensively studied. Various studies have optimized different substrates and physical conditions for the mass production of entomopathogenic fungi in biopesticide synthesis [106,143,144]. Samšiňáková [145], Mal-abika [146], Elawati [147], and Krasnoff [148] have discussed the submerged process/liquid-based fermentation process for the mass production of *B. bassiana*. The common ingredients of the fermentation medium used for *B. bassiana* production contain peptone and sorbitol as nitrogen and carbon sources, respectively, and maintain the broth at pH 5. Besides sorbitol, other carbon sources such as glucose, soluble starch, and corn-steep have been applied for *B. bassiana* production. The incubation temperature of the batch process has to be maintained at 28 °C for 10–14 days to gain 10¹³ conidia/mL of *B. bassiana* biomass. Generally, fungi favored growth over a lower pH (5.6–5.9) with an optimum temperature at 28 °C. However, starch and sucrose are the most common carbon sources supplemented to entomopathogenic fungi for biopesticide production [137,141]. Xu [149] and Jacobson [150] have reported the preference for the carbon source, namely sucrose, while studying the growth and cultivation in biopesticide production using three distinct entomopathogenic fungi *Cordyceps militaris* (strains NG3 and C378) and *Paecilomyces sinclairii*.

Various virus-based biopesticides, composed of viruses such as Baculoviruses (BVs), Coviruses, Iridoviruses, Granuloviruses (GVs), Nucleopolyhedrosis viruses (NPVs), Poxviruses, and Parvoviruses, have gained popularity over the last few decades as biocon-
trol agents (Table 2). Baculovirus-based biopesticides are highly exploited for the biocontrol of insects [151]. An occlusion body (OB) is the active ingredient of baculovirus biopesticides, which are occluded and hold virions inside a polyhedral coat. Currently, bioreactors are used for the production of OB on a commercial scale. Traditional methods of baculovirus biopesticides production required the infection of caterpillars and complex recovery processes. Bioreactors not only reduced the production costs but also enhanced the quality of synthesized baculovirus biopesticides by increasing higher yields of OB/cell [151].

Presently, *Helicoverpa armigera* virus/*Helicoverpa zea* cell systems are used to produce baculovirus biopesticides with an initial 2×10¹² OB/L concentration. The process of baculovirus biopesticide production includes infection, the serial passage of proliferated virus (PV), and OB production [152]. Further, the derived OBs from caterpillars were digested with an alkaline solution for more than 30 minutes, neutralized in the VPM3 solution, and filter-sterilized. Later, OB are inoculated to a fed-batch bioreactor consisting of *H. zea* cells at rate of 5×10⁵ cells/mL, and baculovirus is harvested at 4 days post-infection [153].

Entomopathogenic nematodes (EPNs) are characterized by non-segmented round-worms that are either obligate or facultative insect parasites found in soil, mainly comprising two genera: *Steinernema* and *Heterorhabditis*. They have been accepted as bioinsecticides [154]. EPNs can possibly mass-cultured in vivo (using a dead insect body function as a bioreactor in a symbiotic association with bacteria) or in vitro (using solid and liquid media, such as kidney extract, beef fat, and pig's kidney, along with symbiotic bacteria for axenic culture, e.g., *Steinernema glaseri*) [154].

Entomopathogenic protozoans (EPPs) are cultivated in vivo, and the nurturing of infected hosts (*Melanoplus bivittatus*) is a prime factor in the mass production of EPP. The presence of light, harvesting time, species used in production, and sex of host are important parameters for the mass production of EPP (*Nosema pyrausta*, *N. locustae*) [155]. The production process begins by rearing grasshoppers exposed to *N. locustae* spore suspension until they die. The collected cadaver is crushed, sieved, and centrifuged to obtain a high mass of spore (10⁹ spore/individual), which are then maintained at -20 °C [155].

## 3.2. Temperature

The sporulation and delta-endotoxin of the bacterium *B. thuringiensis* depend on the environmental temperature in which the batch process is executed. Exposure to higher temperatures causes stress in *B. thuringiensis*, prompting early sporulation and low toxin production concentrations. A wide temperature range has been reported for various toxins. Özkan [156] reported that the optimal temperature for the production of the toxin Cry4Ba and Cry11Aa by *B. thuringiensis* var. *israelensis* HD500 was observed at 25 °C and 30 °C, respectively. Similarly, Zhang [157] reported the recovery of delta-endotoxin from *B. thuringiensis* strain var. *kurstaki* BM35 at 30 °C using food waste with varying water concentrations. Several studies have suggested the optimal temperature for the production of delta-endotoxin from *B. thuringiensis* strains is between 25 and 30 °C [156–158].

Temperature is one of the major environmental parameters that affects the viability, propagation, and virulence of entomopathogenic fungi [92]. Generally, high temperatures cause destructive losses in conidial survival; however, high humidity robustly supports the germination of fungal conidia [159]. Different fungal species of entomopathogenic fungi-based biopesticides have distinct temperature needs. For example, most strains of *B. bassiana* have a favorable temperature for conidial growth and vegetative development at 25 ± 1 °C [160]. *B. bassiana* has been reported to be highly efficient in controlling *R. dominica*, and *S. oryzae* at 26 °C than at 30 °C [161], and *S. granarius* [162]. *Isaria fumosorosea* was more potent at 20 °C than at 25 °C [163], whereas the *M. anisopliae* has effectively inhibited *T. confusum* larvae at enhanced temperatures [164]. Mostly entomopathogenic fungi, like other fungi, show favorable growth and sporulation between 25 and 32 °C.

Mostly entomopathogenic viruses are associated with the Baculoviridae family of rod-shaped particles and sub-divided into two genera granulosis virus (GV) and nuclear
polyhedrosis virus (NPV). Humidity, temperature, and sunlight, particularly ultraviolet (UV) rays, are the core climatic factors that decide the efficacy of entomopathogenic virus-based biopesticides in insect control [165]. For instance, parameters for *Spodoptera mauritia* (Boisduval) NPV, specific heating treatment effects at particular temperatures, such as 48 h at 70 °C, showed no impact on virus survivability. However, enhancing sunlight exposure to 72 h and heating up to 90 °C effectively decreased virus survivability, and the virus became completely inactive at high temperatures of 95 °C for a long sunlight exposure of 96 h [166]. In addition to providing the optimum temperature for effective physicochemical conditions, the role of temperature on the mode of biopesticide action has a significant effect.

Successful pest control by biopesticides is the outcome of the development of triangu-
lar complex interactions between the biocontrolling microbial agent, the target insect, and
the local environment. Some studies have reported the functional efficiency of temperature
on Bt strain sporulation and viability [167–169]. A report revealed a direct proportion-
ality between temperature and Bt toxicity to Choristoneura fumiferana [170], Choristoneura
rosaceana [171], and Spodoptera litura [172]. Exposure to higher temperatures over long
periods (3 to 10 days) decreases Bt viability and toxicity, whereas lower temperatures
(15 °C) support toxicity even up to five months of storage [166,173].

3.3. *Aeration*

Focusing on the importance of aeration (oxygen supply) in the fed-batch process for the higher production of crystal toxin from *B. thuringiensis* var. *kurstaki* and *B. thuringiensis* var. *israelensis* werestudied by Boniolo [118], Mounsef [167], and Rodríguez [158]. Studies were conducted to gain a higher yield of crystal protein by maintaining an oxygen gradient of 5%, 20%, and 50% (dissolved oxygen) in the batch process, supplementing glucose as carbon source to proliferate *B. thuringiensis* growth. The level of higher aeration resulted in a 7–9-fold increase in spore counts and noticeably enhanced the virulent behavior of the process compared to the lower aeration regime. Studies imply that the interruption of oxygen tension significantly decreased sporulation and abated toxin formation [118,158,167]. Further, extending aeration caused bacterial cell multiplication, but toxin formation was suppressed significantly. Jackson [174] studied on entomopathogenic fungus *Isaria fumosorosea* cultures, which revealed that dissolved oxygen (>20%) availability is essential for significant *I. fumosorosea* growth.

3.4. *Non-Conventional Substrates for Biopesticide Production*

According to the study, nearly 40% of the production cost of biopesticides includes the cost of raw material [175]. Therefore, the ingredients of biopesticide production media should include locally available, less expensive C/N raw material sources. Several studies showed that cost-effective C/N raw material sources can be obtained from agro-food-industrial waste, such as barley flour [176], bird feathers, and deoiled rice bran [177], brewer's yeast extract [178], broiler litter extract [179], cheese whey, cane molasses [180], glycerol from the biodiesel industry [181], fish meal and gruel [182-184], wheat bran [167], soybean meal, soya bean milk, soy flour [182], molasses with corn steep liquor [183], milky effluent, and beer wastewater [182] for delta-endotoxin production from *B. thuringiensis*. Vu [117], Ndao [185], and Kumar [186] have reported on the application of starch industry wastewater as a substrate for the production of *B. thuringiensis* var. *kurstaki* biopesticide in batch and fed-batch process modes. Vu [117] has optimized the fed-batch process for *B. thuringiensis* var. *kurstaki*-based biopesticide production, in which the strain was fed twice at 10 and 20 h during a long process of 72 h and recovered high delta-endotoxin toxin (1672.6 mg/L), while a lower concentration of delta-endotoxin (511 mg/L) was obtained in the batch process without feeding. Moreover, some other agro-residues, such as *Lantana camara*, paddy straw, wheat straw, sugarcane bagasse, maize cobs, and lignocellulose substrates can be utilized for waste substrates of promising microbes in order to make the process cost-effective [187].
Recently, wastewater sludge has been optimized in China as a raw material for *B. thuringiensis* growth and delta-endotoxin production [188–190]. The processed sludge has nutrient properties containing carbon, nitrogen, and phosphorus (C:N:P) at 279.4:27.6:8.2 g/kg and a pH of 6.86 [188]. In this study, four different substrates, such as a commercial medium enriched with 79.4% of cereal bran coupled with 17.3% N source, 3.3% mineral salts, 100% sludge, 66.7% sludge + 33.3% wheat bran, 66.7% sludge, and 33.3% straw powder, have been supplemented to *B. thuringiensis* var. *kurstaki* with a 2% inoculum volume in a batch process for delta-endotoxin production. Among the substrates, the substrate combination with 66.7% sludge and 33.3% wheat resulted in the highest production of delta-endotoxin (7.14 mg/g) from *B. thuringiensis* var. *kurstaki*.

Sivakalai and Ramanathan [191] optimized various naturally produced, including vegetables (*Momordica charantia*, *Moringa oleifera*, *Musa acuminata*, *Solanum tuberosum*), oil cakes (*Cocos nucifera* oil cakes, *Cocos nucifera* cakes, *Arachis hypogaea* cakes, *Helianthus annuus* cakes), and agro-industrial wastes such as *Oryza sativa* grain, boiled bran, raw bran, *Oryza sativa* husk and powder, as well as whey to evaluate the mass cultivation of two entomopathogenic fungi like *B. bassiana* and *M. anisopliae*. Among the different agro-industrial waste, rice grain showed higher spore production. Moreover, apart from rice grain, green banana, potato, rice husk, and rice powder also resulted in growth and sporulation at 28 °C in 15 days. The spore multiplication of *B. bassiana* and *M. anisopliae* was assayed in novel whey, millet, and barley-based culture media [192–194]. Spore yield and viability were estimated in two strains, GHA-726 and CA-603, of *B. bassiana* and two strains, CA-1 and IMI 330189, of *M. anisopliae* [192,193]. The strains were inoculated for cultivation in three different whey-based systems, viz., solid, liquid, and a diphasic production system. The researchers reported that saturated whey can be considered for the spore multiplication of entomopathogenic fungi, effective in *B. bassiana* and *M. anisopliae*. Moreover, spore production and survival were considerably affected by fungal isolate, ingredient concentration, and the type of production processes used.

## 4. Microbial Strains Improvement for Better Biopesticide Production

The use of propagation techniques and the manipulation of microbial strains to achieve consistent improvements in biopesticide production through biotechnological or metabolic engineering tools is known as "strain improvement". Advances in "OMICS" approaches and high-throughput equipment have gained significant understanding pertinent to metabolic pathways that regulate the biopesticide production in microbes. Recent studies on genome editing through the CRISPR/Cas9 tool and its variants have shown promising results for the development of biopesticides [195]. Zhu et al. developed a robust *B. thuringiensis* strain with high melanin production using the CRISPR/Cas9 system. Researchers reported that this strain possessed 80% insecticidal activity against the cotton bollworm, *Helicoverpa armigera*, compared to the 20% insecticidal activity exhibited by the control sample [196]. Microbial strain improvement implies not only a higher production of desired bioactive compounds but also that it should be cost-effective and eco-friendly, necessitating the exploration of new techniques for efficient processes based on the end product. Genetic modifications aim to produce chitinase, trichodiene synthase, trehalase, antibiotics, toxins, and neurotoxin genes to arrest the growth of pests [197,198]. Some studies with varied strategies for biopesticides production are illustrated subsequently.

Chitin is a substrate found in the fungal cell wall and in the exoskeleton of arthropods and insects. Chitin is digested by chitinase enzymes, which can be used as biopesticides to control the fungus. Vahed [197] attempted to enhance chitinolytic activity of *Bacillus pumilus* SG2 using UV irradiation and nitrous acid treatment to enhance chitinolytic activity. *Bacillus pumilus* SG2 is a halotolerant strain that expresses two main chitinases, viz., *ChiS* and *ChiL*. Nucleotide sequences of the entire chitinase operon from the SG2 and AV2-9 strains revealed a mutation in the GH18 gene of chitinase (*ChiL*, wild type). Further, it has been reported that the mutant (*ChiLm*) showed enhanced ChiL chitinase activity (30% higher) under optimal conditions.
Phenazine-1-carboxylic acid, a compound secreted by *Pseudomonas* spp. has been commercialized as an antifungal pesticide under the brand name of “Shenqinmycin”. The biocontrol strain *Pseudomonas chlororaphis* GP72 synthesizes three antifungal compounds, including phenazine derived products: phenazine-1-carboxylic acid; 2-hydroxyphenazine, and 2-hydroxy-phenazine-1-carboxylic acid. However, the production of 2-hydroxyphenazine by *Pseudomonas chlororaphis* GP72 is low and has been improved from 4.5 to 450 mg/L through gene knockout [198]. In another study, Tijerino [199] extracted and cloned the *tri5* gene, which encodes the expression of trichodiene synthase, into wild *T. brevicompactum* using a metabolic engineering approach. This approach is effective against *Aspergillus fumigatus* and *Fusarium* infections.

Entomopathogenic fungi secrete digestive enzymes into hemolymph and, upon subsequent insertion into the cuticle layer, promotes sugar utilization. *Metarhizium acridum* excretes an enzyme trehalase, specifically acidic trehalase *metarhizium* 1 (ATM1), which can digest trehalose, the major carbohydrate present in insect hemolymphs [200]. The involvement of biotechnological tools in metabolic engineering has enabled the development of a mutant of *M. acridum* with the potential to overexpress the ATM1 gene after successfully reaching the locust hemocoel. This enhancement increased the development of *M. acridum* in the locust hemocoel and minimized LC₅₀ compared to the wild-type strain [122]. This strategy developed the parasitic nature of biocontrol agents, as entomopathogenic fungi would siphon the nutrients from the target insect, thereby enhancing virulence.

An improved biocontrol strain was developed by transferring the cloned antibiotic (phenazine-1-carboxylic acid) genes, 12 kb in size, isolated from *Pseudomonas fluorescens* 2-79 into *Pseudomonas putida* and *Pseudomonas fluorescens* to secrete high quantities of antibiotics through biotechnological tools [201]. Haas [102] extracted a cosmid from *Pseudomonas fluorescens* CHAO, which contains a 22 kb insert and antibiotic genes involved in the production of pyoluteorin and phloroglucinol. Using a metabolic engineering approach, Haas [155] modified the *Pseudomonas fluorescens* CHAO to produce the antibiotics, pyoluteorin and phloroglucinol, at levels four times higher than the wild type. The mutant strain *Pseudomonas fluorescens* CHAO has the capacity to protect the cucumber crops from *Pythium ultimum* and *Rhizoctonia solani* pathogens.

A broad variety of genes encoding insect-specific toxins, extracted from scorpions (*Androctonus australis* neurotoxin AaIT) and spiders (Beta/delta-agatoxin-1), were inserted into the genomes of *Metarhizium* or *Beauveria* spp. [197,202–204]. The insect-specific toxins typically cause rapid paralysis by disrupting major ion channels like Na⁺, K⁺, Ca²⁺, and Cl⁻ [202,203,205]. The scorpion toxin binds to the sodium channel and blocks the expression of AaIT1 (*Androctonus australis* insect toxin) gene. The AaIT1 gene has been introgressed into the *Metarhizium anisopliae* strain (ARSEF 549), and the genetically modified strain has a 40% increased killing efficiency of the target pest [204,206]. Further, the integration of the scorpion toxin *BmKit* (*Buthus martensi* (Karsch) insect toxin) gene from *Buthus martensi* into *Lecanicillium lecanii* resulted not only in a 7.1-fold reduction in lethal concentration but also a 26.5% decrease in the survival rate of pests [95,206,207]. “Trypsin-modulating oostatic factor” (TMOF), an ovary inhibiting factor, has the potential to cease the biosynthesis of the trypsin enzyme that disintegrates protein in the *Culicidae* gut after blood feeding. The transformation and expression of the TMOF genes extracted from *Aedes aegypti* in *Bassiana* sp. are effective against insect pests [207–209].

Developing recombinant baculovirus-based biopesticides are very expensive. It involves a laborious, time-consuming, and high-skill process for high-quality viral DNA isolation, followed by 100% transfection [208]. However, recombinant DNA technology has been applied to baculovirus isolated from *Pyemotes tritici* to develop an effective biopesticide. The transformed baculovirus (vEV-Tox34) is capable of over-expressing the *Tox-34* gene against the pest *Helicoverpa zea* [210]. Similarly, insect-specific neurotoxin genes from two spiders, *Duguetia canities* and *Tegenaria agrestis*, have been genetically transformed into *Autographa californica* multicapsid Nuclear Polyhedrosis Virus (AcMNPV), resulting
in mutant strains vAcTaITX-1 and vAcDTX9.2. These modified strains have been used commercially against lepidopteran insects [208].

*Lymantria dispar* multicapsid nucleopolyhedrovirus (LdMNPV) is occasionally applied as a biocontrol agent against gypsy moths (*Lymantria dispar*). A recombinant strain of baculovirus viral (vEGT) was developed, which was incapable of secreting the enzyme ecdysteroid UDP-glucosyltransferase (EGT), thereby hindering normal insect molting [211]. Additionally, various genes have been successfully transformed into baculovirus to develop viral biopesticides, including *Androctonusaustralis* neurotoxin, *Buthuseupeus* insect toxin-1, *B. thuringiensissurstaki* HD-73 delta-endotoxin, the *Heliothis virescens* juvenile hormone esterase, the *Manduca sexta* diuretic hormone, the *P. tritici* TXP-I toxin, Doi mV gene, and T-urf 13 genes [209].

Recently, the genome editing tools, namely the CRISPR-Cas9 system, have been used to improve biopesticide efficiency. Pazmiño-Ibarra [212] reported the strain improvement of baculovirus (recombinant AcMNPV) through the knockout of several genes using the CRISPR tool, resulting in enhanced biopesticide activity. Wang [213] utilized the CRISPR technique to examine the resistance gene present in Asian corn borer (*Ostrinia furnacalis*) against *B. thuringiensis* Cry1A/Cry1F toxins and successfully knocked out the resistant gene, leading to more effective biocontrol of *O. furnacalis*.

## 5. Biocontrol Mechanisms of Microbial Agents against Major Pests

The mode of action of biopesticides is a critical component that impacts the potential for pest decrease, host targeting, efficient application, coherent response, and non-target susceptibility [214]. Broadly, microbial biopesticides have three modes of action: (i) biological or ecological, (ii) physical, and (iii) chemical or biochemical. Physical control may require the creation of barriers, while biological control uses predation or competition modes of action. In the case of biochemical action, it disrupts genetic material or biochemical pathways in the targeted pest. Biopesticides mostly utilize combinatorial modes of action to reduce the risk of resistance development. The modes of action of various microbial agents of biopesticides, belonging to bacteria, fungi, virus, nematodes, and protozoa and their target pests, are described in Table 3.

<table><caption>**Table 3.** Biopesticide mode of action against pathogens.</caption><thead><tr><td>Biopesticide Type</td><td>Category</td><td>Target Pest</td><td>Mode of Action</td><td>References</td></tr></thead><tbody><tr><td>Bacteria</td><td></td><td></td><td></td><td></td></tr><tr><td>Bacillus subtilis</td><td>Fungicide</td><td>Rhizoctonia, Fusarium, Alternaria, Verticillium, Streptomyces, Aspergillus</td><td>Colonizes the plant root and produces antibiotic iturin A in soil which shows antifungal activity against phytopathogens besides inducing defense response in plants.</td><td>[5,111]</td></tr><tr><td>Pseudomonas fluorescens</td><td>Fungicide/Bactericide</td><td>Effective against P. solani on mushrooms and Erwinia on fruit crops</td><td>Crowds out and controls the growth of plant pathogens.</td><td>[62,112]</td></tr><tr><td>Streptomyces setonii WY228</td><td>Fungicide</td><td>Ceratocystis fimbriata</td><td>Volatiles 2-ethyl-5-methylpyrazine and dimethyl disulfide significantly inhibited the mycelial growth and spore germination of C. fimbriata.</td><td>[113]</td></tr><tr><td>Fungi</td><td></td><td></td><td>Infects insects at all stages, viz., eggs, larvae, pupae grabs, nymphs, hopper, and adult. The spores attached to insect cuticle, germinate and penetrate the hyphae into the insect body causing mortality.</td><td>[91]</td></tr><tr><td>Beauveria bassiana</td><td>Insecticide</td><td>Foliar feeding insects</td><td>Mycoparasitic. It kills the fungi with a toxin and consumes it after dissolving by releasing lytic enzymes.</td><td>[53,215]</td></tr><tr><td>Trichoderma viride/harzianum</td><td>Fungicide</td><td>Soil-borne fungal disease</td><td></td><td></td></tr></tbody></table>
<table><caption>Table 3. *Cont.*</caption><thead><tr><td>Biopesticide Type</td><td>Category</td><td>Target Pest</td><td>Mode of Action</td><td>References</td></tr></thead><tbody><tr><td>Muscodor albus</td><td>Fumigant with fungicidal, bactericidal and insecticidal properties</td><td>Post-harvest pathogens (bacteria, fungi nematode, and arthropod) in storage</td><td>Release complex mixture of volatile toxins against pest</td><td>[216,217]</td></tr><tr><td>Metarhizium anisopliae<br>Virus</td><td>Fungicide</td><td>Effective against root weevils, Japanese beetle, spittlebug, black vine weevil, and white grubs</td><td>Fungal spores penetrate the host body through the cuticle, proliferates, extract the insect of nutrients</td><td>[218]</td></tr><tr><td>Nucleopolyhedrosis virus (NPV)</td><td>Insecticide</td><td>Specific for species of lepidoptera hymenoptera and diptera</td><td>The occlusion bodies with viruses are ingested by insect larvae. Under alkaline pH of the host midgut, the protein of the occlusion body dissolves and degrades by the alkaline proteases. The lipoprotein membrane of the released virus attaches to the host gut membrane and releases nucleocapsids into the cytoplasm. The viral DNA transported into the cell nucleus for multiplication and fills the host body with virus particles. The virus multiplies either in epithelial cells or tracheal matrix. The rod-shaped virion is occluded in capsules. The virions upon ingestion into the insect causes death in 6-20 days.</td><td>[219,220]</td></tr><tr><td>Granulosis virus (GV)<br>Nematodes</td><td>Insecticide</td><td>Specific species of Lepidoptera</td><td>The virus multiplies either in epithelial cells or tracheal matrix. The rod-shaped virion is occluded in capsules. The virions upon ingestion into the insect causes death in 6-20 days.</td><td>[143,221]</td></tr><tr><td>Heterorhabditis bacteriophora</td><td>Insecticide</td><td>Effective against many soil insects, lepidopteran larvae, Japanese beetles, and turf</td><td>Infected juveniles of H. bacteriophora enter the insect's larval body cavity through mouth, anus, spiracles, and inter-segmental membranes of cuticle. These infective nematode juveniles release symbiotic bacteria (Photorhabdus spp.) into the blood of insects, where the multiplication of nematode-bacterium complex occurs rapidly. These complexes cause septicemia and kills the host within 48 h of infection. The juvenile S. glaeri penetrates the insect through spiracles, mouth, anus, and inter-segmental membranes of the cuticle and enters into the hemocoel. The bacteria multiply in the insect hemolymph and the infected host usually dies within 24 to 48 h. The juveniles of S. feltiae carry Xenorhabdus bovienii, a symbiotic bacterium in their gut. The microbes multiply rapidly in the insect blood and kill its host within 48 h of infection by causing septicemia,</td><td>[222]</td></tr><tr><td>Steinernema glaseri</td><td>Insecticide</td><td>Effective against fleas, fungal gnats, root weevils, cutworms, and borers</td><td>The juvenile S. glaeri penetrates the insect through spiracles, mouth, anus, and inter-segmental membranes of the cuticle and enters into the hemocoel. The bacteria multiply in the insect hemolymph and the infected host usually dies within 24 to 48 h. The juveniles of S. feltiae carry Xenorhabdus bovienii, a symbiotic bacterium in their gut. The microbes multiply rapidly in the insect blood and kill its host within 48 h of infection by causing septicemia,</td><td>[223-225]</td></tr><tr><td>Steinernema feltiae<br>Protozoa</td><td>Insecticide</td><td>Effective against beet armyworm, codling moth, corn earworm, vine weevils, fungus gnats, leafminers, mushroom flies, fruit flies, sciarid flies</td><td>It infects the grasshopper and ingests the spores that germinate in the gut and affects the digestive system. The sporoplasm enters fat body tissue and effectively starves the host energy reserves. The juveniles of S. feltiae carry Xenorhabdus bovienii, a symbiotic bacterium in their gut. The microbes multiply rapidly in the insect blood and kill its host within 48 h of infection by causing septicemia,</td><td>[225]</td></tr><tr><td>Nosema locustae</td><td>Insecticide</td><td>Effective against grasshoppers and crickets</td><td>It infects the grasshopper and ingests the spores that germinate in the gut and affects the digestive system. The sporoplasm enters fat body tissue and effectively starves the host energy reserves. The juveniles of S. feltiae carry Xenorhabdus bovienii, a symbiotic bacterium in their gut. The microbes multiply rapidly in the insect blood and kill its host within 48 h of infection by causing septicemia,</td><td>[226]</td></tr><tr><td>Nosema pyrausta</td><td>Insecticide</td><td>Effective against European corn borer</td><td>Microsporidian of N. pyrausta causes mortality of moth larvae by reducing its fecundity and longevity. Infective spores of L. dispar are formed in the gut adjacent muscle and connective tissue. The insect starves due to disruption in feeding behavior and ultimately dies.</td><td>[227]</td></tr><tr><td>Vairimorpha disparis</td><td>Insecticide</td><td>Effective against Lymantria dispar</td><td>Microsporidian of N. pyrausta causes mortality of moth larvae by reducing its fecundity and longevity. Infective spores of L. dispar are formed in the gut adjacent muscle and connective tissue. The insect starves due to disruption in feeding behavior and ultimately dies.</td><td>[228]</td></tr></tbody></table>
B. thuringiensis is a soil-borne bacterium exploited for biopesticide development [229]. This bacterium produces parasporal crystalline inclusions containing crystal (Cry) and cytolytic (Cyt) proteins. The Cry and Cyt proteins (also called delta-endotoxins) are toxic against insects, caterpillars, beetles, and flies. B. thuringiensis strains synthesize the toxins at the commencement of sporulation as parasporal crystalline inclusions during the stationary growth phase. However, B. thuringiensis also has the potential to synthesize insecticidal proteins and secrete them into the growth medium during the log growth phase [229]. The secreted crystal toxins are host-specific in their actions, thus gaining attention globally as an alternative to synthetic insecticides. The action mechanism of B. thuringiensis-based toxin is depicted in Figure 2. Inactive crystal inclusion enters the larva by ingestion and dissolves in the gut under alkaline conditions. The solubilization of Cry protein occurs in the gut by proteases, gaining 60–70 kDa protease-resistant proteins [211]. Later, the activation of Cry protein begins with the slicing of the N-terminal from Cry1 protoxin. Activated protein binds to the brush-like structure of column-shaped epithelium cells of the midgut prior to passing into the cellular membrane. The primary action of crystal toxin is to lyse the midgut epithelial cell and form pores in the apical membrane cell, resulting in the leakage of ions and cell lysis [213,230].

<figure><img src="image_3.png" /><figcaption>**Figure 2.** Mechanism of *Bacillus thuringiensis* (Bt) toxicity to insects. The expressed and inactive Bt toxin present in the genetically modified organism (GMO)/transgenic plant and its toxicity initiated once the plant portion is ingested by the insect larvae.</figcaption></figure>

Chitinases are hydrolytic enzymes capable of controlling the chitin exoskeleton in fungi and insects [231]. One of the attractive and environmentally safe strategies is the application of chitinase-producing microbes as biopesticides. Chitinolytic enzyme-producing microbes can hydrolyze the fungal cell wall and integument of insects [232]. Chitin is a polysaccharide and polymer of N-acetylglucosamine linked by β-1,4 glycosidic bonds. Chitinases enzymes are prominently reported in bacteria, fungi, and insects [213]. Chitinase-producing bacteria and fungi are extremely important for synthesizing biopesticides.

Chitinases secreted by the bacteria are allowed to adhere to the plant portion with the help of suitable carriers. The chitinase enzyme becomes active once the insect engulfs the chitinase-producing bacteria anchored on the plant portion. Bacteria adapt themselves in the gut of larvae and release chitinases, which digest the chitin in the peritrophic membrane available in larvae. The damaged peritrophic membrane of the insect results in its death [233]. Similarly, the cell walls of pathogenic fungi are also composed of chitin substrate. Over the interaction between bacteria and pathogenic fungi, chitinase-secreting microbes stimulate the release of chitinase enzymes that cleave β-1,4 glycosidic bonds of chitin present in the cell wall of pathogenic fungi. Besides the above-mentioned biocontrol mechanisms, biocontrol agents release secondary metabolites to inhibit or destroy pests, such as volatile organic compounds; cyclic lipopeptides; phenazines; 2,4-diacetylphloroglucinol; pyoluteorin; and pyrrolnitrin, and extracellular lytic enzymes, such as proteases; lipase; and β-1,3 glucanase.
## 6. Biopesticide Formulations

In the past few decades, the injudicious application of pesticides has resulted in environmental concerns. Biopesticides are effective, eco-friendly, and environmentally sustainable in application. Hence, biopesticide treatment has been included in integrated pest management (IPM) programs to control the pest effectively. Biopesticides are highly target-specific, and their application is highly advantageous. However, developing commercially acceptable bioformulations is extremely complex. Biopesticides must be in a portable format to maintain their biocontrol activity of microbial agents throughout storage and during application [234]. Hence, commercial biopesticides should be economical to reproduce, have apt storage stability, be easy to handle, have high miscibility, and have a repetitive impact on killing target pests [235]. Some commercialized biopesticides brands with microbial strains as key ingredients used in agriculture are given in Table 4.

<table><caption>**Table 4.** Biopesticide product brands and manufacturers [Adapted from [236,237]].</caption><thead><tr><td>Active Ingredient</td><td>Class</td><td>Target Pests</td><td>Product</td><td>Company</td></tr></thead><tbody><tr><td>Metarhizium anisopliae</td><td>Fungus</td><td>Thrips, mites, whiteflies</td><td>Met52®, GreenGuard®, Green Muscle®</td><td>Novozymes (Chiba, Japan), BASF (Ludwigshafen, Germany)</td></tr><tr><td>Isaria fumosorosea strain Apopka 97</td><td>Fungus</td><td>Sucking insects, mites, and black vine weevil</td><td>PFR-97®</td><td>Certies USA (Columbia, MD, USA)</td></tr><tr><td>Trichoderma harzianum T-22</td><td>Fungus</td><td>Pathogenic fungi</td><td>RootShiel®, PlantShield®</td><td>BioWorks (Victor, NY, USA)</td></tr><tr><td>Trichoderma Viride</td><td>Fungus</td><td>Pathogenic fungi</td><td>BIODERMA</td><td>Biotech International Ltd. (Greater Noida, India)</td></tr><tr><td>Gliocladium virens</td><td>Fungus</td><td>Pathogenic fungi</td><td>SoilGard®</td><td>Certis USA</td></tr><tr><td>Trichoderma asperellum and T. gamsii</td><td>Fungi</td><td>Pathogenic fungi</td><td>BIO-TAM2.0®, BIOZIM</td><td>Isagro (Marrone Bio (Davis, CA, USA)), Philippines University, Philippines, PA, USA</td></tr><tr><td>Chromobacterium subtsugae</td><td>Bacterium</td><td>Sucking and chewing insects, mites, and flies</td><td>Grandevo®</td><td>Marrone Bio Innovations (Davis, CA, USA)</td></tr><tr><td>Burkholderia rinojensis</td><td>Bacterium</td><td>Sucking, chewing insects, mites, and flies</td><td>Venerate®</td><td>Marrone Bio Innovations</td></tr><tr><td>Bacillus subtilis 713</td><td>Bacterium</td><td>Antifungal</td><td>Serenade®, Cease®</td><td>Bayer (Leverkusen, Germany)</td></tr><tr><td>Bacillus subtilis</td><td>Bacterium</td><td>Antifungal</td><td>Utkarsh BaciSub</td><td>Utkarsh Agrochem Ltd., Kamrej, Gujrat, India</td></tr><tr><td>Bacillus amyloliquefaciens D747</td><td>Bacterium</td><td>Antifungal</td><td>DoubleNickel® 55</td><td>Certis USA</td></tr><tr><td>Bacillus pumilus 2808</td><td>Bacterium</td><td>Antifungal</td><td>Sonata®</td><td>Bayer (Leverkusen, Germany) (Wilbur Ellis (San Francisco, CA, USA))</td></tr><tr><td>Bacillus amyloliquefaciens F727</td><td>Bacterium</td><td>Antifungal</td><td>Stargus™, Amplitude™</td><td>Marrone Bio Innovations</td></tr><tr><td>Bacillus mycoides isolate J</td><td>Bacterium</td><td>Antifungal</td><td>LifeGard™ WG</td><td>Certis SUA</td></tr><tr><td>Bacillus thuringiensis subsp. Aizawai</td><td>Bacterium</td><td>Diamondback moth, armyworm</td><td>XenTari®, Agree</td><td>Valent BioSciences (Libertyville, IL, USA), Certis USA</td></tr><tr><td>Bacillus thuringiensis</td><td>Bacterium</td><td>Diamondback moth, armyworm</td><td>Utkarsh BT</td><td>Utkarsh Agrochem Ltd., Kamrej, Gujrat, India</td></tr><tr><td>Bacillus thuringiensis var. kurstaki</td><td>Bacterium</td><td>A broad range of caterpillars</td><td>Dipel®, Deliver®, Foray®, Biobit®, Javelin®, Actinovate®, ActinoGrow®</td><td>Valent BioSciences</td></tr><tr><td>Streptomyces lydicus</td><td>Actinomycete</td><td>Antifungal</td><td></td><td>Novozymes (Valent)</td></tr></tbody></table>

Various studies have revealed that microorganisms have the potential to inhibit or control crop pests through several mechanisms. The biocontrol potential of microbes can
be influenced by inoculum size, inoculum age, and delivery mechanism. Therefore, it
is essential to prepare a formulation with microbial agents in which effective inoculum
sizes, ages, and other essential factors are standardized to ensure, effective, and repetitive
biocontrol results in field conditions. The formulation process resulting in a final biopesti-
cide product involves the incorporation of the microbial agent with different carriers or
adjuvants. Pertinent to their physical state, biopesticides can be broadly classified into
dry and liquid formulations. Dry formulations can be prepared using various technolo-
gies like freeze-drying, spray-drying, and air-drying. Dry biopesticides are prepared by
mixing binders, dispersants, wetting agents, and other essential components [238]. As
the biocontrol agent used in biopesticides is a crucial factor in its commercialization, the
preparation of biopesticide formulation requires the application of a carrier to enhance the
shelf life of the biocontrol agent in the formulated product. Carriers used in dry biopesticide
formulation can elevate the viability of microbes by shielding them from dryness and other
adverse environmental factors. Some carriers used for dry biopesticides development are
alginate, lignite, kaolinite, montmorillonite, peat, pyrophyllite, press mud, sawdust, turf,
talc, vermiculite, and zeolite [239].

Comparatively, talc has been accepted as a carrier for dry bioformulation preparation
due to its extremely small particle size. Several studies suggest that biopesticides have been
formulated using talc as an effective carrier and coating agent. Anitha and Rabeeth [240]
used *Streptomyces griseus* as a biocontrol agent to prepare biopesticide against *Fusarium*
wilt in tomato using a talc-based carrier. Meena [241] used a talc-carrier-based biopesticide
formulation of *Pseudomonas fluorescens* for effective seed treatment and foliar application
against plant pathogens. Mohanraj [242] developed a bacterial-based biopesticide with
*Bacillus subtilis* and used talc with 1% carboxymethyl cellulose as a binder, traces of sodium
benzoate as a stabilizer, 15% CaCO₃ as buffer agents, and 0.25% of different enriched
nutrients as an ingredient to protect the mulberry crop against *Macrophomina phaseolina* and
*Fusarium oxysporum*. Besides talc as a carrier in biopesticide formulation, silica precipitate
can also be used. Swami [243] evaluated several carriers, viz., barium sulphate, bentonite,
dolomite, fuller's earth, kaolin, talc, precipitate of silica, and pyrophyllite, for developing
wettable carrier powder and reported silica precipitate as a superior wettable carrier
powder for the preparation of biopesticide formulations with *B. thuringiensis* var. *kurstaki*.
The developed biopesticides were effective against *Helicoverpa armigera*. However, talc-
based dry biopesticide formulations are not durable as the microbes used in the talc-based
formulation are not sustained for much longer due to the depletion or lack of nutrients in
the formulation [244].

Solid-based biopesticide formulations have some drawbacks, such as the uniform
distribution of microbial agents in the field, small coverage area, and poor field perfor-
mance [245]. Carriers of solid-based biopesticide formulation give rise to health concerns
for farmers over inhalation or contact [246]. The solid-based biopesticides have a short shelf
life of the microbial agents used in biopesticide synthesis [247]. During the management of
plant pathogens in the field through the micro-irrigation systems, solid formulations have
given rise to concerns pertinent to the nozzle blockages and the non-uniform distribution
of the microbial inoculum. Further, there are limitations associated with the application of
solid-based bioformulations in horticultural plantlets, tissue culture plants, and hydroponic
systems. Hence, it is necessary to develop liquid-based bioformulations of biopesticides for
extended use.

Liquid formulations are water-, oil-, or polymer-based bioformulations and are clas-
sified as suspension concentrate (water), emulsions (oil), or capsule suspension (poly-
mer). Liquid bioformulations are amended with inert ingredients like chemical nutri-
ents, antifreeze compounds, pH stabilizers, gluing agents, surfactants, and coloring com-
pounds [248]. Liquid formulations offer a longer shelf life than solid-based formulations,
have high purity, demonstrate free activity of carriers, are comfortable in handling and uses,
and have storage and transport convenience, easy quality control, and enhanced export
value [184]. Liquid bioformulation is also accordant with chemical sprayer machinery on a large scale and, therefore, highly accepted by farmers and agro-industries [249].

Studies have revealed that common additives like glycerol, polyvinylpyrrolidone, carboxymethyl cellulose, gum arabic, sucrose, and trehalose are successfully used for liquid biopesticide reparation; and these additives protect the cells from desiccation, osmotic pressure, and temperature stress [250–252]. In liquid formulations, the microbes are active ingredients in the hibernating cyst/spore format, and the microbial cells trigger activity upon application in the field. Hence, these additives enhance the shelf life of liquid bio- formulation for a long period [247,253]. Manikandan et al. [254] examined the effect of different additives in liquid formulations to maintain the population level of *Pseudomonas fluorescens* and found that glycerol (10 mM) resulted in the preservation of 9.8 × 10⁷ cfu/mL microbial population for 180 days. Further, when glycerol was added to liquid formulations of *B. thuringiensis* (Bt) and exposed at room temperature for one month, it was found that Bt cells were still able to control *Helicoverpa armigera* compared to solid formulations. Besides the delivery mechanism of biopesticides, some of the other important factors that decide the function and success of biopesticide application in field are deposition (dust and soil parti- cles on vegetation), climatic conditions (temperature), uniform distribution of biopesticide solution (coverage), inoculum age and application volume (10⁸⁻⁹ microbial cell/mL).

The stability and environmental impact of microbial pesticides are of great concern. The influences of biotic and abiotic factors on the potential of microbial biopesticides are considerably high. However, nanotechnology intervention can play a potential role in minimizing harmful environmental concerns [255,256]. There is an urgent need for an effective delivery mechanism of microbial biopesticides. Nanomaterial-bound biopesti- cides protect agricultural products from the major pests in the fields as well as in the warehouses [257–259]. Evolving immobilization technology with the intervention of the nanomaterials as carrier supports and improves the stability and efficiency of the biopesti- cides [260,261].

## 7. Challenges in Microbial Biopesticides

Biopesticides offer a considerable contribution to sustainable agriculture [262]. Currently, the application of biopesticide is limited to horticultural crops compared to synthetic pesticides [96,263]. Microbial biopesticides, compared to synthetic pesticides, have many advantages, such as being environmentally benign, free of harmful residues, and cost-effective to manufacture [264]. However, one of the major challenges of microbial biopesticides is their narrow-spectrum application due to the high host-specific action of biopesticides. This specific affinity hampers further use against other pests. Consequently, it may require the search for other multiple microbial biopesticides [264]. In addition, microbial biopesticides have a couple of issues that need to be addressed, such as barriers at the interface of patents and the non-availability of publicly funded research outcome, the non-uniformity of regulatory guidelines, and ecological interference [263].

Nanoencapsulation techniques provide a protective milieu for biopesticides. Nanomaterials have a higher surface area-to-volume ratio, which confirms the high adsorption of substrates [265]. Nanomaterials have many advantageous features, including slow-releasing properties; enhanced properties like solubility, shelf life, and stability; and overall efficiency of the microbial pesticides. The efficiency of microbial biopesticides is improved in two ways: safe delivery of active ingredients and enhanced longer delivery time. In addition to the minimum effective dose of the biopesticide, minimum exposure to human beings further safe-guard against ill effects to ecosystems [266].

The application of microbial biopesticides, compared to conventional pesticides, is not equivalent to the share of the total crop protection market. Moreover, most microbial biopesticides are restricted to a single bacterium, *B. thuringiensis*. The global market for biopesticides is merely a small share, exhibiting a meagre 5% of the total plant protection market [267]. More research and development should focus on discovery novel microorganisms suitable for potential biopesticides.
Moreover, there is an unequal distribution of biopesticides in global markets, e.g., higher biopesticide products are being used in the USA compared to the European Union [268]. Due to the stringent regulation adopted in the European Union, there is no discrimination between the registration policies of chemical pesticides versus biopesticides. Thus, it will slow the registration of new biopesticide products and their applications in the European Union. That is why fewer biopesticide products are being registered in the European Union compared to other countries, including India, China, and the US. There is an urgent need to address this challenge by adopting specific regulations for biopesticide registration [269]. This potential method will minimize the time from the discovery of the microbial biopesticide to the commercialization of the product [270]. Thus, the uniformity of biopesticide regulations at the global level would facilitate the rapid commercialization of biopesticide products. Moreover, public cooperation in adopting microbial biopesticides would simplify the enhanced biocontrol of major pests.

## 8. Conclusions

Microbial biopesticides, a safer technology, offer considerable benefits to the biopesticide industry. Recent advances in nanobiotechnology further improve the stability and efficacy of biopesticides. The residual action of biopesticides improves with the progress made in encapsulation techniques using advanced nanocarriers, which are more beneficial to field use. It is opined that uniformity and timely bound regulation norms for microbial biopesticides would provide a platform to meet the demands of sustainable agriculture.

**Author Contributions:** Conceptualization, M.L.V.; writing—original draft preparation, A.K., A.D.C., P.J.K.S., and M.L.V.; writing—review and editing, M.L.V., A.K., A.D.C., P.J.K.S., M.B., and E.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** One of the authors, Madan L. Verma, is grateful to the Director of the Indian Institute of Information Technology Una, Himachal Pradesh, for providing the necessary facility to pursue the present work.

**Conflicts of Interest:** The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

## References

1. UNO. Our Growing Population. 2020. Available online: https://www.un.org/en/global-issues/population (accessed on 22 April 2021).

2. Awad, N.E.; Kassem, H.A.; Hamed, M.A.; El-Feky, A.M.; Elnaggar, M.A.; Mahmoud, K.; Ali, M.A. Isolation and characterization of the bioactive metabolites from the soil derived fungus *Trichoderma viride*. *Mycology* **2018**, *9*, 70–80. [CrossRef]

3. Qian, X.; Chen, L.; Sui, Y.; Chen, C.; Zhang, W.; Zhou, J.; Dong, W.; Jiang, M.; Xin, F.; Ochsenreither, K. Biotechnological potential and applications of microbial consortia. *Biotechnol. Adv.* **2020**, *40*, 107500. [CrossRef]

4. Venbrux, M.; Crauwels, S.; Rediers, H. Current and emerging trends in techniques for plant pathogen detection. *Front. Plant Sci.* **2023**, *14*, 1120968. [CrossRef] [PubMed]

5. Chandrasekaran, R.; Revathi, K.; Thanigaivel, A.; Kirubakaran, S.A.; Senthil-Nathan, S. *Bacillus subtilis* chitinase identified by matrix-assisted laser desorption/ionization time-of flight/time of flight mass spectrometry has insecticidal activity against *Spodoptera litura* Fab. *Pest. Biochem. Physiol.* **2014**, *116*, 1–12. [CrossRef]

6. Chintagunta, A.D.; Kumar, S.P.J.; Krishna, S.M.; Manvitha, A.; Kumar, N.S.S. Studies on bioconversion of agri-waste to biomanure. *Indian J. Ecol.* **2020**, *47*, 116–121.

7. Datta, S.; Rajnish, K.N.; Samuel, M.S.; Pugazlendhi, A.; Selvarajan, E. Metagenomic applications in microbial diversity, bioremediation, pollution monitoring, enzyme and drug discovery A review. *Environ. Chem. Lett.* **2020**, *18*, 1229–1241. [CrossRef]

8. Nawaz, M.; Mabubu, J.I.; Hua, H. Current status and advancement of biopesticides: Microbial and botanical pesticides. *J. Entomol. Zool. Stud.* **2016**, *4*, 241–246.

9. Maciag, T.; Koziel, E.; Rusin, P.; Otulak-Koziel, K.; Jafra, S.; Czajkowski, R. Microbial Consortia for plant protection against diseases: More than the sum of its parts. *Int. J. Mol. Sci.* **2023**, *24*, 12227. [CrossRef]

10. Swapan, C.; Mainak, B.; Deewa, B.; Tanmoy, M. Natural pesticides for pest control in agricultural crops: An alternative and eco-friendly method. *Plant Sci. Today* **2024**, *11*, 433–450. [CrossRef]
11. Umesha, S.; Singh, P.K.; Singh, R.P. Microbial biotechnology and sustainable agriculture. In *Biotechnology for Sustainable Agriculture*; Woodhead Publishing: Sawston, UK, 2018; pp. 185–205.

12. Nascimento, T.A.; de Carvalho, K.S.; Martins, D.C.; de Oliveira, C.R.; de Carvalho Queiroz, M.M.; Valicente, F.H. *Bacillus thuringiensis* strains to control Noctuidae pests. *J. Appl. Entomol.* **2024**, *148*, 371–381. [CrossRef]

13. Mishra, J.; Dutta, V.; Arora, N.K. Biopesticides in India: Technology and sustainability linkages. *3 Biotech* **2020**, *10*, 210. [CrossRef] [PubMed]

14. Rangasamy, K.; Athiappan, M.; Devarajan, N.; Samykannu, G.; Parray, J.A.; Aruljothi, K.N.; Abdullah, E.F. Pesticide degrading natural multidrug resistance bacterial flora. *Microb. Pathog.* **2017**, *114*, 304–310. [CrossRef]

15. Mnyone, L.L.; Koenraadt, C.J.M.; Lyimo, I.N.; Mpingwa, M.W.; Takken, W.; Russell, T.L. Anopheline and culicine mosquitoes are not repelled by surfaces treated with the entomopathogenic fungi *Metarhizium anisopliae* and *Beauveria bassiana*. *Para. Vectors* **2010**, *3*, 80. [CrossRef]

16. Rehner, S.A.; Kepler, R.M. Species limits, phylogeography and reproductive mode in the *Metarhizium anisopliae* complex. *J. Invertebr. Pathol.* **2017**, *114B*, 60–66. [CrossRef] [PubMed]

17. Sánchez-Rodríguez, A.R.; Raya-Díaz, S.; Zamarreño, Á.M.; García-Mina, J.M.; del Campillo, M.C.; Quesada-Moraga, E. An endophytic *Beauveria bassiana* strain increases spike production in bread and durum wheat plants and effectively controls cotton leafworm (*Spodoptera littoralis*) larvae. *Biol. Control* **2018**, *116*, 90–102. [CrossRef]

18. Sharma, S.; Malik, P. Biopesticides: Types and applications. *Int. J. Adv. Pharma. Biol. Chem.* **2012**, *14*, 508–515.

19. Dong, W.T.; Xiao, L.F.; Hu, J.J.; Zhao, X.X.; Liu, J.X.; Zhang, Y. iTRAQ proteomic analysis of the interactions between *Bombyx mori* nuclear polyhedrosis virus and silkworm. *J. Proteom.* **2017**, *166*, 138–145. [CrossRef] [PubMed]

20. Anderson, A.J.; Kim, Y.C. Biopesticides produced by plant-probiotic *Pseudomonas chlororaphis* isolates. *Crop Prot.* **2018**, *105*, 62–69. [CrossRef]

21. Tetreau, G.; Patil, C.D.; Chandor-Proust, A.; Salunke, B.K.; Patil, S.V.; Després, L. Production of the bioinsecticide *Bacillus thuringiensis* subsp. *israelensis* with deltamethrin increases toxicity towards mosquito larvae. *Lett. Appl. Microbiol.* **2013**, *57*, 151–156. [CrossRef]

22. Chandrasena, D.I.; Signorini, A.M.; Abratti, G.; Storer, N.P.; Olaciregui, M.L.; Alves, A.P.; Pilcher, C.D. Characterization of field-evolved resistance to *Bacillus thuringiensis*-derived Cry1F δ-endotoxin in *Spodoptera frugiperda* populations from Argentina. *Pest Manag. Sci.* **2018**, *74*, 746–754. [CrossRef]

23. Jiang, C.H.; Liao, M.J.; Wang, H.K.; Zheng, M.Z.; Xu, J.J.; Guo, J.H. *Bacillus velezensis*, a potential and efficient biocontrol agent in control of pepper gray mold caused by *Botrytis cinerea*. *Biol. Control* **2018**, *126*, 147–157. [CrossRef]

24. Leathers, T.D.; Saunders, L.P.; Bowman, M.J.; Price, N.P.J.; Bischoff, K.M.; Rich, J.O.; Skory, C.D.; Nunnally, M.S. Inhibition of *Erwinia amylovora* by *Bacillus nakamurai*. *Curr. Microbiol.* **2020**, *77*, 875–881. [CrossRef] [PubMed]

25. Allard, S.M.; Micallef, S.A. The Plant Microbiome: Diversity, dynamics, and role in food safety. In *Safety and Practice for Organic Food*; Academic Press: Cambridge, MA, USA, 2019; pp. 229–257. [CrossRef]

26. Ruiu, L. Microbial biopesticides in agroecosystems. *Agronomy* **2018**, *8*, 235. [CrossRef]

27. Arora, N.K.; Mishra, J. Prospecting the roles of metabolites and additives in future bioformulations for sustainable agriculture. *Appl. Soil. Ecol.* **2016**, *107*, 405–407. [CrossRef]

28. Kumar, A.; Imran, M.; Kumar, S.P.J.; Kumar, M.; Singh, A.N.; Srivastava, A.K. Assessment of soil urease activity and its kinetic parameters in chilli rhizosphere under the influence of pesticides. *Biopestic. Int.* **2018**, *14*, 47–57.

29. Kumar, A.; Agarwal, D.K.; Kumar, S.; Reddy, Y.M.; Chintagunta, A.D.; Saritha, K.V.; Pal, G.; Kumar, S.J. Nutraceuticals derived from seed storage proteins: Implications for health wellness. *Biocatal. Agric. Biotechnol.* **2019**, *17*, 710–719. [CrossRef]

30. Marrone, P.G. Pesticidal natural products–status and future potential. *Pest Manag. Sci.* **2019**, *75*, 2325–2340. [CrossRef]

31. Mishra, J.; Tewari, S.; Singh, S.; Arora, N.K. Biopesticides: Where we stand? In *Plant Microbes Symbiosis: Applied Facets*; Springer: New Delhi, India, 2015; pp. 37–75. [CrossRef]

32. Lima, D.B.; Melo, J.W.S.; Guedes, N.M.P.; Gontijo, L.M.; Guedes, R.N.C.; Gondim, M.G.C., Jr. Bioinsecticide-predator interactions: Azadirachtin behavioral and reproductive impairment of the coconut mite predator *Neoseiulus baraki*. *PLoS ONE* **2015**, *10*, e0118343. [CrossRef] [PubMed]

33. Bravo, A.; Likitvivatanavong, S.; Gill, S.S.; Soberón, M. *Bacillus thuringiensis*: A story of a successful bioinsecticide. *Insect Biochem. Mol. Biol.* **2011**, *41*, 423–431. [CrossRef]

34. Anderson, R.K.I.; Jayaraman, K. Influence of carbon and nitrogen sources on the growth and sporulation of *Bacillus thuringiensis* var Galleriae for biopesticide production. *Chem Biochem. Eng. Q.* **2003**, *17*, 225–232.

35. Frederiks, C.; Wesseler, J.H.H. A comparison of the EU and US regulatory frameworks for the active substance registration of microbial biological control agents. *Pest Manag. Sci.* **2019**, *75*, 87–103. [CrossRef]

36. Wafa, J.; Fatma, D.; Luc, F.; Souad, R. Review on biopesticide production by *Bacillus thuringiensis* subsp. kurstaki since 1990: Focus on bioprocess parameters. *Process Biochem.* **2020**, *98*, 224–232. [CrossRef]

37. Saddam, B.; Idrees, M.A.; Kumar, P.; Mahamood, M. Biopesticides: Uses and importance in insect pest control: A review. *Int. J. Trop. Insect Sci.* **2024**. [CrossRef]

38. He, Y.; Zhu, M.; Huang, J.; Hsiang, T.; Zheng, L. Biocontrol potential of a *Bacillus subtilis* strain BJ-1 against the rice blast fungus *Magnaporthe oryzae*. *Can. J. Plant Pathol.* **2019**, *41*, 47–59. [CrossRef]
39. García-Bastidas, F.A.; Quintero-Vargas, J.C.; Ayala-Vasquez, M.; Schermer, T.; Seidl, M.F.; Santos-Paiva, M.; Noguera, A.M.; Aguilera-Galvez, C.; Wittenberg, A.; Hofstede, R.; et al. First report of *Fusarium* wilt Tropical Race 4 in Cavendish bananas caused by *Fusarium odoratissimum* in Colombia. *Plant Dis.* **2020**, *104*, 994. [CrossRef]

40. Hussain, T.; Khan, A.A. *Bacillus subtilis* HussainT-AMU and its antifungal activity against potato black scurf caused by *Rhizoctonia solani* on seed tubers. *Biocatal. Agric. Biotechnol.* **2020**, *23*, 101443. [CrossRef]

41. Gadhi, M.A.; Nizamani, Z.A.; Jatoi, G.H.; Abro, M.A.; Keerio, A.U.; Poussio, G.B.; Qiu, D. In-vitro efficacy of bio-control agent and essential oils against leaf blight of chickpea caused by Alternaria alternata. *Acta Ecol. Sin.* **2020**, *40*, 166-171. [CrossRef]

42. Dawood, M.A.; Eweedah, N.M.; Moustafa, E.M.; Shahin, M.G. Synbiotic effects of *Aspergillus oryzae* and β-glucan on growth and oxidative and immune responses of nile Tilapia, *Oreochromis niloticus*. *Probiotics Antimicrob. Prot.* **2020**, *12*, 172-183. [CrossRef] [PubMed]

43. Yao, Q.; Xu, S.; Dong, Y.; Lu, K.; Chen, B. Identification and characterisation of two general odourant-binding proteins from the litchi fruit borer, *Conopomorpha sinensis* Bradley. *Pest Manag. Sci.* **2016**, *72*, 877-887. [CrossRef]

44. Raza, M.F.; Yao, Z.; Dong, X.; Cai, Z.; Zhang, H. Citrus insect pests and their non-chemical control in China. *Citrus Res. Technol.* **2017**, *38*, 122-138. [CrossRef]

45. de Lillo, E.; Pozzebon, A.; Valenzano, D.; Duso, C. An intimate relationship between *Eriophyoid* mites and their host plants—A review. *Front. Plant Sci.* **2018**, *9*, 1786. [CrossRef] [PubMed]

46. Wainwright, C.; Jenkins, S.; Wilson, D.; Elliott, M.; Jukes, A.; Collier, R. Phenology of the Diamondback Moth (*Plutella xylostella*) in the UK and provision of decision support for *Brassica* growers. *Insects* **2020**, *11*, 118. [CrossRef] [PubMed]

47. Tian, X.; Li, Y.; Hao, N.; Su, X.; Du, J.; Hu, J.; Tian, X. The antifeedant, insecticidal and insect growth inhibitory activities of triterpenoid saponins from *Clematis aethusifolia* Turcz against *Plutella xylostella* (L.). *Pest Manag. Sci.* **2021**, *77*, 455-463. [CrossRef]

48. Tepa-Yotto, G.T.; Chinwada, P.; Rwomushana, I.; Goergen, G.; Subramanian, S. Integrated management of *Spodoptera frugiperda* 6 years post detection in Africa: A review. *Curr. Opin. Insect Sci.* **2022**, *52*, 100928. [CrossRef]

49. Houngbo, S.; Zannou, A.; Aoudji, A.; Sossou, H.C.; Sinzogan, A.; Sikirou, R.; Zossou, E.; Vodounon, H.S.; Adomou, A.; Ahanchédé, A. Farmers’ knowledge and management practices of fall armyworm, *Spodoptera frugiperda* (JE Smith) in Benin, West Africa. *Agriculture* **2020**, *10*, 430. [CrossRef]

50. Silva, A.C.; Silva, G.A.; Abib, P.H.; Carolino, A.T.; Samuels, R.I. Endophytic colonization of tomato plants by the entomopathogenic fungus *Beauveria bassiana* for controlling the South American tomato pinworm, *Tuta absoluta*. *CABI Agric. Biosci.* **2021**, *1*, 3. [CrossRef]

51. Murali Sankar, P.; Shreedevasena, S. Desert locusts (*Schistocerca gregaria*)—A global threatening transboundary pest for food security. *Biotica Res. Today* **2020**, *2*, 389-391.

52. Zhang, G.f.; Ma, D.Y.; Wang, Y.S.; Gao, Y.H.; Liu, W.X.; Zhang, R.; Fu, W.J.; Xian, X.Q.; Wang, J.; Kuang, M.; et al. First report of the South American tomato leafminer, *Tuta absoluta* (Meyrick), in China. *J. Integr. Agric.* **2020**, *19*, 1912-1917. [CrossRef]

53. Mishra, J.; Arora, N.K. Secondary metabolites of fluorescent pseudomonads in biocontrol of phytopathogens for sustainable agriculture. *Appl. Soil. Ecol.* **2018**, *125*, 35-45. [CrossRef]

54. Rasheed, T.; Rizwan, K.; Bilal, M.; Sher, F.; Iqbal, H.M.N. Tailored functional materials as robust candidates to mitigate pesticides in aqueous matrices—A review. *Chemosphere* **2021**, *282*, 131056. [CrossRef]

55. Zhuang, L.; Zhou, S.; Wang, Y.; Chang, M. Mosquito biolarvicide production by sequential fermentation with dual strains of *Bacillus thuringiensis* subsp. israelensis and *Bacillus sphaericus* using sewage sludge. *Bioresour. Technol.* **2010**, *102*, 1574-1580. [CrossRef] [PubMed]

56. Suman, S.; Kumar, M.; Singh, B.K.P. Field Efficacy of Insecticides against *Conopomorpha sinensis* Bradley (Lepidoptera: Gracillariidae): A Major Pest of Litchi and its Management in Bihar, India. *Int. J. Plant Sci.* **2024**, *36*, 211-215. [CrossRef]

57. Leroy, L.; Mille, C.; Fogliani, B. The common fruit-piercing moth in the Pacific Region: A Survey of the current state of a significant Worldwide Economic Pest, *Eudocima phalonia* (Lepidoptera: Erebidae), with a focus on New Caledonia. *Insects* **2021**, *12*, 117. [CrossRef]

58. Mohan, C.; Nair, C.R.; Nampoothiri, C.K.; Rajan, P. Leaf-eating caterpillar (*Opisina arenosella*)-induced yield loss in coconut palm. *Int. J. Trop. Insect Sci.* **2010**, *30*, 132-137. [CrossRef]

59. Koul, B.; Taak, P. Lychee (*Litchi chinensis* Sonn.): Pre-and post-harvest disease management. In *Lychee Disease Management*; Springer: Singapore, 2017; pp. 1-26.

60. Biswas, G.C.; Islam, R. Infestation and management of the leaf roller (*Lamprosema indicata* Fab.) in soybean (*Glycine max* L.). *Bangladesh J. Agric. Res.* **2012**, *37*, 19-25. [CrossRef]

61. Rahaman, M.M.; Islam, K.S.; Jahan, M.; Mamun, M.A.A. Relative abundance of stem borer species and natural enemies in rice ecosystem at Madhupur, Tangail, Bangladesh. *J. Bangladesh Agric. Univ.* **2014**, *12*, 267-272. [CrossRef]

62. Pokhrel, M.R. Field Survey of White Grubs and Laboratory Evaluation of *Metarhizium anisopliae* (Metsch.) Sorokin for Its Control with Side Effects on *Bombyx mori* L. in M. Sc. Ag. Ph.D. Thesis, Tribhuvan University, Institute of Agriculture and Animal Science, Chitwan, Nepal, 2004; p. 134, (Unpublished).

63. Hallaji Sani, M.F.; Naseri, B.; Rafiee-Dastjerdi, H.; Aghajanzadeh, S.; Ghadamyari, M. Effects of three conventional insecticides on life table parameters and detoxifying enzymes activity of *Pulvinaria aurantii* Cockerell (Hemiptera: Coccidae). *Toxin Rev.* **2019**, *26*, 1318-1326. [CrossRef]
64. EFSA Panel on Plant Health (PLH); Bragard, C.; Baptista, P.; Chatzivassiliou, E.; Di Serio, F.; Gonthier, P.; Jaques Miret, J.A.; Justesen, A.F.; Magnusson, C.S.; Milonas, P.; et al. Pest categorisation of *Pulvinaria psidii*. *EFSA J. 2022*, *20*, e07526. [CrossRef]

65. Golino, D.A.; Sim, S.T.; Gill, R.; Rowhani, A. California mealybugs can spread grapevine leaf roll disease. *Calif. Agric.* **2002**, *56*, 196–201. [CrossRef]

66. Mohsen, A.M. Survey of insect pests infested guava orchards and infestation of main and off-seasons guava crops a year-round by fruit fly *Ceratitis capitat* (wiedemann). *Middle East. J. Appl. Sci.* **2018**, *8*, 1264–1272.

67. Choudhary, J.S.; Prabhakar, C.S.; Moanaro, D.B.; Kumar, S. Litchi stink bug (*Tessaratoma javanica*) outbreak in Jharkhand, India, on litchi. *Phytoparasitica* **2013**, *41*, 73–77. [CrossRef]

68. Li, H.; Chumroenphat, T.; Boonarsa, P.; Yahuafai, J.; Wrigley, C.; Siriamornpun, S. Evaluation of roasting and grilling effects on chemical composition, volatile profiles, and toxicity of stink bugs (*tessaratoma papillosa*): Implications for utilization as functional food ingredients. *Foods* **2023**, *12*, 3053. [CrossRef] [PubMed]

69. Hafsi, A.; Facon, B.; Ravigné, V.; Chiroleu, F.; Quilici, S.; Chermiti, B.; Duyck, P.F. Host plant range of a fruit fly community (Diptera: Tephritidae): Does fruit composition influence larval performance? *BMC Ecol.* **2016**, *16*, 40. [CrossRef]

70. McLoughlin, A.G.; Wytinck, N.; Walker, P.L.; Girardm, I.J.; Rashid, K.Y.; de Kievit, T.; Fernando, W.D.; Whyard, S.; Belmonte, M.F. Identification and application of exogenous dsRNA confers plant protection against *Sclerotinia sclerotiorum* and *Botrytis cinerea*. *Sci. Rep.* **2018**, *8*, 7320. [CrossRef]

71. Russo, A.; Winkler, J.B.; Ghirardo, A.; Monti, M.M.; Pollastri, S.; Ruocco, M.; Schnitzler, J.P.; Loreto, F. Interaction with the entomopathogenic fungus *Beauveria bassiana* influences tomato phenome and promotes resistance to *Botrytis cinerea* infection. *Fronti. Plant Sci.* **2013**, *14*, 1309747. [CrossRef]

72. Mccallum, B.D.; Seto-Goh, P.; Reimer, E.; Foster, A.; Xue, A. Physiological specialization of *Puccinia triticina*, the causal agent of wheat leaf rust, in Canada in 2013. *Can. J. Plant Pathol.* **2020**, *42*, 243–249. [CrossRef]

73. Tovar-Pedraza, J.M.; Mora-Aguilera, J.A.; Nava-Díaz, C.; Lima, N.B.; Michereff, S.J.; Sandoval-Islas, J.S.; Câmara, M.P.; Téliz-Ortiz, D.; Leyva-Mir, S.G. Distribution and pathogenicity of *Colletotrichum* species associated with mango anthracnose in Mexico. *Plant Dis.* **2020**, *104*, 137–146. [CrossRef]

74. Zhu, J.Z.; Qiu, Z.L.; Gao, B.D.; Li, X.G.; Zhong, J. A novel partitivirus conferring hypovirulence by affecting vesicle transport in the fungus *Colletotrichum*. *Mbio* **2024**, *15*, e02530-23. [CrossRef]

75. Ray, K.; Sen, K.; Ghosh, P.P.; Barman, A.R.; Mandal, R.; De Roy, M.; Dutta, S. Dynamics of *Sclerotium rolfsii* as influenced by different crop rhizosphere and microbial community. *J. Appl. Nat. Sci.* **2017**, *9*, 1544–1550. [CrossRef]

76. Paul, S.K.; Gupta, D.R.; Mahapatra, C.K.; Rani, K.; Islam, T. Morpho-molecular, cultural and pathological characterization of *Athelia rolfsii* causing southern blight disease on common bean. *Heliyon* **2023**, *9*. [CrossRef]

77. Yang, G.; Tang, L.; Gong, Y.; Xie, J.; Fu, Y.; Jiang, D.; Li, G.; Collinge, D.B.; Chen, W.; Cheng, J.A. A cerato-platanin protein SsCP1 targets plant PR1 and contributes to virulence of *Sclerotinia sclerotiorum*. *New Phytol.* **2018**, *217*, 739–755. [CrossRef] [PubMed]

78. Hao, Z.P.; Sheng, L.; Feng, Z.B.; Fei, W.X.; Hou, S.M. Aphids may facilitate the spread of Sclerotinia stem rot in oilseed rape by carrying and depositing ascospores. *J. Fungi* **2024**, *10*, 202. [CrossRef] [PubMed]

79. Chávez-Ramírez, B.; Kerber-Díaz, J.C.; Acoltzi-Conde, M.C.; Ibarra, J.A.; Vásquez-Murrieta, M.S.; Estrada-de Los Santos, P. Inhibition of *Rhizoctonia solani* RhCh-14 and *Pythium ultimum* PyFr-14 by *Paenibacillus polymyxa* NMA1017 and *Burkholderia cenocepacia* CACua-24: A proposal for biocontrol of phytopathogenic fungi. *Microbiol. Res.* **2020**, *230*, 126347. [CrossRef]

80. Adhikari, A.; Oli, D.; Poudel, P.; Magar, P.B.; Pandit, S.; Pokhrel, A.; Gurung, S.B.; Shrestha, J. Pythium-induced damping-off disease and its management in tomato (*Solanum lycopersicum* L.): A review. *Agric. Sci. Technol.* **2024**, *16*, 1313–8820. [CrossRef]

81. Midega, C.A.; Pittchar, J.O.; Pickett, J.A.; Hailu, G.W.; Khan, Z.R. A climate-adapted push-pull system effectively controls fall armyworm, *Spodoptera frugiperda* (JE Smith), in maize in East Africa. *Crop Prot.* **2018**, *105*, 10–15. [CrossRef]

82. Fotso Kuate, A.; Hanna, R.; Doumtso Fotio, A.R.; Abang, A.F.; Nanga, S.N.; Ngatat, S.; Tindo, M.; Masso, C.; Ndemah, R.; Suh, C.; et al. *Spodoptera frugiperda* Smith (Lepidoptera: Noctuidae) in Cameroon: Case study on its distribution, damage, pesticide use, genetic differentiation and host plants. *PLoS ONE* **2019**, *14*, e0217653. [CrossRef]

83. Hailu, G.; Niassy, S.; Bässler, T.; Ochatum, N.; Studer, C.; Salifu, D.; Agbodzavu, M.K.; Khan, Z.R.; Midega, C.; Subramanian, S. Could fall armyworm, *Spodoptera frugiperda* (JE Smith) invasion in Africa contribute to the displacement of cereal stemborers in maize and sorghum cropping systems. *Int. J. Trop. Insect Sci.* **2021**, *41*, 1753–1762. [CrossRef]

84. Li, X.W.; Li, D.; Zhang, Z.J.; Huang, J.; Zhang, J.M.; Hafeez, M.; Wang, L.K.; Guo, W.C.; Lu, Y.B. Supercooling capacity and cold tolerance of the South American tomato pinworm, *Tuta absoluta*, a newly invaded pest in China. *J. Pest. Sci.* **2020**, *19*, 845–858. [CrossRef]

85. Abbas, M.S.T. Genetically engineered (modified) crops (*Bacillus thuringiensis* crops) and the world controversy on their safety. *Egypt. J. Biol. Pest Control* **2018**, *28*, 52. [CrossRef]

86. Karuppiah, V.; Sun, J.; Li, T.; Vallikkannu, M.; Chen, J. Co-cultivation of Trichoderma asperellum GDFS1009 and *Bacillus amyloliquefaciens* 1841 causes differential gene expression and improvement in the wheat growth and biocontrol activity. *Front. Microbiol.* **2019**, *10*, 1068. [CrossRef]

87. Mazrou, Y.S.; Makhlouf, A.H.; Elseehy, M.M.; Awad, M.F.; Hassan, M.M. Antagonistic activity and molecular characterization of biological control agent *Trichoderma harzianum* from Saudi Arabia. *Egypt. J. Biol. Pest. Cont.* **2020**, *30*, 4. [CrossRef]

88. Kumar, S.P.; Banerjee, R. Optimization of lipid enriched biomass production from oleaginous fungus using response surface methodology. *Indian J. Exp. Biol.* **2013**, *51*, 979–983.
89. Banerjee, R.; Chintagunta, A.D.; Ray, S. A cleaner and eco-friendly bioprocess for enhancing reducing sugar production from pineapple leaf waste. *J. Clean. Prod.* **2017**, *149*, 387–395. [CrossRef]

90. Fayad, N.; Abboud, J.; Driss, F.; Louka, N.; Kalfassy Awad, M. Optimization of Culture Conditions and Wheat Bran Class Selection in the Production of *Bacillus thuringiensis* based Biopesticides. *Ferment* **2022**, *8*, 666. [CrossRef]

91. Morris, C.E.; Lamichhane, J.R.; Nikolić, I.; Stanković, S.; Moury, B. The overlapping continuum of host range among strains in the *Pseudomonas syringae* complex. *Phytopathol. Res.* **2019**, *1*, 4. [CrossRef]

92. Dhillon, M.K.; Gujar, G.T. Impact of climate change on arthropod biodiversity and plant protection. *Int. J. Environ. Consum.* **2010**, *6*, 41–45.

93. dos Santos, H.M.; de S. Varize, C.; Valença, C.A.; Dossi, F.C.; de Aragão Batista, M.V.; Fernandes, R.P.; Severino, P.; Souto, E.B.; Dolabella, S.S.; da C. Mendonça, M.; et al. Use of agro-industrial bio-waste for the growth and production of a previously isolated *Bacillus thuringiensis* strain. *Beni-Suef Univ. J. Basic. Appl. Sci.* **2024**, *13*, 5. [CrossRef]

94. Kumar, S.P.J.; Banerjee, R. Enhanced lipid extraction from oleaginous yeast biomass using ultrasound assisted extraction: A greener and scalable process. *Ultrason. Sonochem.* **2019**, *52*, 25–32. [CrossRef] [PubMed]

95. Koul, O.; Dhaliwal, G.S. Advances in biopesticide research. In *Microbial Biopesticides*; Taylor and Francis: Abingdon, UK; CRC Press: London, UK, 2001; Volume II, pp. 1–11. [CrossRef]

96. Montesinos, E. Development, registration and commercialization of microbial pesticides for plant protection. *Int. Microbiol.* **2003**, *6*, 245–252. [CrossRef]

97. Pawar, A.D.; Singh, B. Prospects of botanicals and biopesticides. In *Botanicals and Biopesticides*; Westville Publishing House: New Delhi, India, 1993; Volume 4, pp. 188–196.

98. Zimmermann, G. The entomopathogenic fungus *Metarhizium anisopliae* and its potential as a biocontrol agent. *Pesticide Sci.* **1993**, *37*, 375–379. [CrossRef]

99. Senthil-Nathan, S.A. review of biopesticides and their mode of action against insect pests. In *Environmental Sustainability*; Thangavel, P., Sridevi, G., Eds.; Springer: New Delhi, India, 2015; pp. 49–63. [CrossRef]

100. Ahmed, W.; Yang, J.; Tan, Y.; Munir, S.; Liu, Q.; Zhang, J.; Guanghai, J.; Zhao, Z. *Ralstonia solanacearum*, a deadly pathogen: Revisiting the bacterial wilt biocontrol practices in tobacco and other Solanaceae. *Rhizosphere* **2022**, *21*, 100479. [CrossRef]

101. Wang, Z.; Luo, W.; Cheng, S.; Zhang, H.; Zong, J.; Zhang, Z. *Ralstonia solanacearum*—A soil borne hidden enemy of plants: Research development in management strategies, their action mechanism and challenges. *Front. Plant Sci.* **2023**, *14*, 1141902. [CrossRef]

102. Getu, T.; Mohammed, W.; Seid, A.; Mekete, T.; Kassa, B. Evaluation of the reaction of various potato (*Solanum tuberosum* L.) cultivars to the Meloidogyne incognita and Ralstonia solanacearum disease complex under field conditions. *Potato Res.* **2024**, *67*, 73–91. [CrossRef]

103. Verma, M.L.; Dhanya, B.S.; Wang, B.; Thakur, M.; Rani, V.; Kushwaha, R. Bio-nanoparticles mediated transesterification of algal biomass for biodiesel production. *Sustainability* **2024**, *16*, 295. [CrossRef]

104. Verma, M.L.; Rani, V.; Kumari, R.; Sharma, D.; Kumar, S.; Kushwaha, R. Bioprospecting. In *Phytomicrobiome Interactions and Sustainable Agriculture*; Verma, A., Saini, J.K., Hesham, A.E.-L., Singh, H.B., Eds.; Springer: Berlin/Heidelberg, Germany, 2021; pp. 217–239. [CrossRef]

105. Arthurs, S.; Dara, S.K. Microbial biopesticides for invertebrate pests and their markets in the United States. *J. Invertebr. Pathol.* **2019**, *165*, 13–21. [CrossRef] [PubMed]

106. Corrêa, B.; da Silveira Duarte, V.; Silva, D.M.; Mascarin, G.M.; Júnior, I.D. Comparative analysis of blastospore production and virulence of *Beauveria bassiana* and *Cordyceps fumosorosea* against soybean pests. *Bio. Control* **2020**, *10*, 323–337. [CrossRef]

107. Bamisile, B.S.; Dash, C.K.; Akutse, K.S.; Keppanan, R.; Afolabi, O.G.; Hussain, M.; Qasim, M.; Wang, L. Prospects of endophytic fungal entomopathogens as biocontrol and plant growth promoting agents: An insight on how artificial inoculation methods affect endophytic colonization of host plants. *Microbiol Res.* **2018**, *217*, 34–50. [CrossRef]

108. Sharma, A.; Sharma, I.M.; Sharma, M.; Sharma, K.; Sharma, A. Effectiveness of fungal, bacterial and yeast antagonists for management of mango anthracnose (*Colletotrichum gloeosporioides*). *Egypt. J. Biol. Pest Control* **2021**, *31*, 135. [CrossRef]

109. Vanani, K.D.; Rakholiya, K.B.; Purushotham, P. Prospecting the effectiveness of fungicides and bioagents against *Colletotrichum gloeosporioides* (Penz.). *Penz. Sacc. J. Adv. Biol. Biotechnol.* **2024**, *27*, 216–225. [CrossRef]

110. Little, N.S.; Luttrell, R.G.; Mullen, R.M.; Allen, K.C.; Parys, K.A. Comparative activity of commercial baculovirus formulations against heliothine pests of cotton. *South. Entomol.* **2019**, *44*, 105–115. [CrossRef]

111. Whitley, K.D.; Grimshaw, J.; Roberts, D.M.; Karinou, E.; Stansfeld, P.J.; Holden, S. Peptidoglycan synthesis drives a single population of septal cell wall synthases during division in *Bacillus subtilis*. *Nat. Microbiol.* **2024**, *9*, 1064–1074. [CrossRef] [PubMed]

112. Paliwal, D.; Rabiey, M.; Mauchline, T.H.; Hassani-Pak, K.; Nauen, R.; Wagstaff, C.; Andrews, S.; Bass, C.; Jackson, R.W. Multiple toxins and a protease contribute to the aphid-killing ability of *Pseudomonas fluorescens* PpR24. *Environ. Microbiol.* **2024**, *26*, e16604. [CrossRef]

113. Gong, Y.; Liu, J.Q.; Xu, M.J.; Zhang, C.M.; Gao, J.; Li, C.G.; Xing, K.; Qin, S. Antifungal volatile organic compounds from *Streptomyces setonii* WY228 control black spot disease of sweet potato. *Appl. Environ. Microbiol.* **2022**, *88*, 02317. [CrossRef]

114. Amin, G.; Alotaibi, S.; Youssef, N.A.; Saleh, W.D. Optimization of a fermentation process for bioinsecticide production by *Bacillus thuringiensis*. *World J. Microbiol. Biotechnol.* **2008**, *24*, 2465–2471. [CrossRef]
115. Köhl, J.; Booij, K.; Kolnaar, R.; Ravensberg, W.J. Ecological arguments to reconsider data requirements regarding the environmental fate of microbial biocontrol agents in the registration procedure in the European Union. *Bio. Control* **2019**, *1*, 469–487. [CrossRef]

116. Amin, G.; Alotaibi, S.; Narmen, Y.A.; Saleh, W.D. Bioinsecticide production by the bacterium *Bacillus thuringiensis*. 1. Pattern of cell growth, toxin production and by-product synthesis. *Arch. Agron. Soil Sci.* **2008**, *54*, 387–394. [CrossRef]

117. Vu, K.D.; Tyagi, R.D.; Valéro, J.R.; Surampalli, R.Y. Batch and fed-batch fermentation of *Bacillus thuringiensis* using starch industry wastewater as fermentation substrate. *Bioprocess Biosyst. Eng.* **2010**, *33*, 691–700. [CrossRef] [PubMed]

118. Boniolo, F.S.; Rodrigues, R.C.; Prata, A.M.R.; López, M.L.; Jacinto, T.; da Silveira, M.M.; Berbert-Molina, M.A. Oxygen supply in *Bacillus thuringiensis* fermentations: Bringing new insights on their impact on sporulation and δ-endotoxin production. *Appl. Microbiol. Biotechnol.* **2012**, *94*, 625–636. [CrossRef]

119. Devidas, P.C.; Pandit, B.H.; Vitthal Rao, P.S. Evaluation of different culture media for improvement in bioinsecticides production by indigenous *Bacillus thuringiensis* and their application against larvae of *Aedes aegypti*. *Sci. World J.* **2014**, *2014*, 273030. [CrossRef]

120. An, B.; Zhan, Y.; Cheng, Q.; Cai, J.; Gu, X. Production improvement and photoprotection of melanin produced by *Bacillus thuringiensis*. *BioControl* **2024**, *69*, 157–167. [CrossRef]

121. Li, Y.; Wang, C.; Ge, L.; Hu, C.; Wu, G.; Sun, Y.; Song, L.; Wu, X.; Pan, A.; Xu, Q.; et al. Environmental Behaviors of *Bacillus thuringiensis* (Bt) Insecticidal Proteins and Their Effects on Microbial Ecology. *Plants* **2022**, *11*, 1212. [CrossRef]

122. Peng, G.; Jin, K.; Liu, Y.; Xia, Y. Enhancing the utilization of host trehalose by fungal trehalase improves the virulence of fungal insecticide. *Appl. Microbiol. Biotechnol.* **2015**, *99*, 8611–8618. [CrossRef]

123. Lormendez, C.C.; Fernandez-Ruvalcaba, M.; Adames-Mancebo, M.; Hernandez-Velazquez, V.M.; Zuñiga-Navarrete, F.; Flores-Ramirez, G.; Lina-Garcia, L.; Peña-Chora, G. Mass production of a S-layer protein of *Bacillus thuringiensis* and its toxicity to the cattle tick *Rhipicephalus microplus*. *Sci. Rep.* **2019**, *9*, 17586. [CrossRef] [PubMed]

124. Brar, S.K.; Verma, M.; Tyagi, R.D.; Valéro, J.R. Recent advances in downstream processing and formulations of *Bacillus thuringiensis* based biopesticides. *Process Biochem.* **2006**, *41*, 323–342. [CrossRef]

125. Hung, T.P.; Truong, L.V.; Binh, N.D.; Frutos, R.; Quiquampoix, H.; Staunton, S. Persistence of detectable insecticidal proteins from *Bacillus thuringiensis* (*Cry*) and toxicity after adsorption on contrasting soils. *Environ. Pollut.* **2016**, *208*, 318–325. [CrossRef] [PubMed]

126. Pacheco, S.; Gómez, I.; Sánchez, J.; García-Gómez, B.I.; Czajkowsky, D.M.; Zhang, J.; Soberón, M.; Bravo, A. Helix α-3 intermolecular salt bridges and conformational changes are essential for toxicity of *Bacillus thuringiensis* 3D-Cry toxin family. *Sci. Rep.* **2018**, *8*, 10331. [CrossRef]

127. Masri, M.M.; Ariff, A.B. Effect of different fermentation strategies on *Bacillus thuringiensis* cultivation and its toxicity towards the bagworm, *Metisa plana* Walker (Lepidoptera: Psychidae). *Egypt. J. Biol. Pest Control* **2020**, *30*, 2. [CrossRef]

128. Berbert-Molina, M.A.; Prata, A.M.R.; Pessanha, L.G.; Silveira, M.M. Kinetics of *Bacillus thuringiensis* var. israelensis growth on high glucose concentrations. *J. Ind. Microbiol. Biotechnol.* **2008**, *35*, 1397–1404. [CrossRef]

129. Sadek, K.H.A. Studies on some factors affecting growth and sporulation of *Bacillus thuringiensis*. In *Faculty of Science*, Cairo University: Giza, Egypt, 2000.

130. Kai, M.; Effmert, U.; Piechulla, B. Bacterial-plant-interactions: Approaches to unravel the biological function of bacterial volatiles in the rhizosphere. *Front. Microbiol.* **2016**, *7*, 108. [CrossRef]

131. Anderson, A.J.; Kang, B.R.; Kim, Y.C. The Gac/Rsm signaling pathway of a biocontrol bacterium, *Pseudomonas chlororaphis* O6. *Res. Plant Dis.* **2017**, *23*, 212–227. [CrossRef]

132. Ruffner, B.; Péchy-Tarr, M.; Ryffel, F.; Hoegger, P.; Obrist, C.; Rindlisbacher, A.; Keel, C.; Maurhofer, M. Oral insecticidal activity of plant-associated pseudomonads. *Environ. Microbiol.* **2013**, *15*, 751–763. [CrossRef]

133. Kupferschmied, P.; Maurhofer, M.; Keel, C. Promise for plant pest control: Root-associated pseudomonads with insecticidal activities. *Front. Plant Sci.* **2013**, *4*, 287. [CrossRef]

134. Goodman, J.; Mclean, J.E.; Britt, D.W.; Anderson, A.J. Sublethal doses of ZnO nanoparticles remodel production of cell signaling metabolites in the root colonizer *Pseudomonas chlororaphis* O6. *Environ. Sci. Nano* **2016**, *3*, 1103–1113. [CrossRef]

135. Sosa, M.F.; Sobrero, P.; Valverde, C.; Agaras, B. A black-pigmented pseudomonad isolate with antibacterial activity against phyllospheric pathogens. *Rhizosphere* **2020**, *15*, 100207. [CrossRef]

136. DeBritto, S.; Gajbar, T.D.; Satapute, P.; Sundaram, L.; Lakshmikantha, R.Y.; Jogaiah, S.; Ito, S.I. Isolation and characterization of nutrient dependent pyocyanin from *Pseudomonas aeruginosa* and its dye and agrochemical properties. *Sci. Rep.* **2020**, *10*, 1542. [CrossRef] [PubMed]

137. Litwin, A.; Nowak, M.; Różalska, S. Entomopathogenic fungi: Unconventional applications. *Rev. Environ. Sci. Bio.* **2020**, *1*, 23–42. [CrossRef]

138. Baiyee, B.; Pornsuriya, C.; Ito, S.I.; Sunpapao, A. *Trichoderma spirale* T76-1 displays biocontrol activity against leaf spot on lettuce (*Lactuca sativa* L.) caused by *Corynespora cassiicola* or *Curvularia aeria*. *Biol. Control* **2019**, *129*, 195–200. [CrossRef]

139. Zeng, W.; Wang, D.; Kirk, W.; Hao, J. Use of *Coniothyrium minitans* and other microorganisms for reducing *Sclerotinia sclerotiorum*. *Biol. Control* **2012**, *60*, 225–232. [CrossRef]

140. Abbas, H.; Javed, N.; Khan, S.A.; Kamran, M.; Atiq, M. Exploitation of nematicidal potential of *Paecilomyces lilacinus* against root knot nematode on eggplant. *Int. J. Veg. Sci.* **2016**, *22*, 85–90. [CrossRef]

141. van Lenteren, J.C.; Bolckmans, K.; Köhl, J.; Ravensberg, W.J.; Urbaneja, A. Biological control using invertebrates and microorganisms: Plenty of new opportunities. *BioControl* **2018**, *63*, 39–59. [CrossRef]
142. Zaki, O.; Weekers, F.; Thonart, P.; Tesch, E.; Kuenemann, P.; Jacques, P. Limiting factors of mycopesticide development. *Biol. Control* **2020**, *144*, 104220. [CrossRef]

143. Kachhawa, D. Microorganisms as a biopesticides. *J. Entomol. Zool. Stud.* **2017**, *5*, 468–473.

144. Jaber, L.R.; Ownley, B.H. Can we use entomopathogenic fungi as endophytes for dual biological control of insect pests and plant pathogens? *Bio. Control* **2018**, *16*, 36–45. [CrossRef]

145. Samšiňáková, A.; Kalalova, S.; Vlček, V.; Kybal, J. Mass production of *Beauveria bassiana* for regulation of *Leptinotarsa decemlineata* populations. *J. Invertebrate Pathol.* **1981**, *38*, 169–174. [CrossRef]

146. Malabika, D.; Mondal, P.; Mandal, S.K. Effect of different liquid media on growth and sporulation of *Beauveria bassiana* in stationary culture. *J. Mycopathol. Res.* **2017**, *55*, 299–301.

147. Elawati, N.E.; Pujiyanto, S.; Kusdiyantini, E. Production of extracellular chitinase *Beauveria bassiana* under submerged fermentation conditions. *J. Phys. Conf. Ser.* **2018**, *1025*, 012074. [CrossRef]

148. Krasnoff, S.B.; Howe, K.J.; Heck, M.L.; Donzelli, B.G. Siderophores from the entomopathogenic fungus *Beauveria bassiana*. *J. Nat. Prod.* **2020**, *83*, 296–304. [CrossRef] [PubMed]

149. Xu, C.P.; Yun, J.W. Optimization of submerged-culture conditions for mycelial growth and exo-biopolymer production by *Auricularia polytricha* (wood ears fungus) using the methods of uniform design and regression analysis. *Biotechnol. Appl. Bioc.* **2003**, *38*, 193–199. [CrossRef]

150. Jacobson, A.; Foster, R.; Krupke, C.; Hutchison, W.; Pittendrigh, B.; Weinzierl, R. Resistance to pyrethroid insecticides in *Helicoverpa zea* (Lepidoptera: Noctuidae) in Indiana and Illinois. *J. Econ. Entomol.* **2009**, *102*, 2289–2295. [CrossRef]

151. Szewczyk, B.; Rabalski, L.; Krol, E.; Sihler, W.; de Souza, M.L. Baculovirus biopesticides—A safe alternative to chemical protection of plants. *J. Biopesticides* **2009**, *2*, 209–216. [CrossRef]

152. Reid, S.; Lua, L. Method of Producing Baculovirus. Patent WO, WO/2005/045014, 2005. Available online: https://aiche.onlinelibrary.wiley.com/doi/abs/10.1002/btpr.1529 (accessed on 7 October 2022).

153. Nguyen, Q.; Qi, Y.M.; Wu, Y.; Chan, L.C.; Nielsen, L.K.; Reid, S. In vitro production of *Helicoverpa* baculovirus biopesticides—Automated selection of insect cell clones for manufacturing and systems biology studies. *J. Virol. Methods* **2011**, *175*, 197–205. [CrossRef] [PubMed]

154. Sharma, M.P.; Sharma, A.N.; Hussaini, S.S. Entomopathogenic nematodes, a potential microbial biopesticide: Mass production and commercialisation status—A mini review. *Arch. Phytopathol. Plant Prot.* **2011**, *44*, 855–870. [CrossRef]

155. Shi, W.P.; Wang, Y.Y.; Lv, F.; Guo, C.; Cheng, X. Persistence of *Paranosema (Nosema) locustae* (Microsporidia: Nosematidae) among grasshopper (Orthoptera: Acrididae) populations in the Inner Mongolia Rangeland, China. *BioControl* **2009**, *54*, 77–84. [CrossRef]

156. Özkan, M.; Dilek, F.B.; Yetis, U.; Özcengiz, G. Nutritional and cultural parameters influencing antidipteran delta-endotoxin production. *Res. Microbiol.* **2003**, *154*, 49–53. [CrossRef]

157. Mejias, L.; Estrada, M.; Barrena, R.; Gea, T. A novel two-stage aeration strategy for Bacillus thuringiensis biopesticide production from biowaste digestate through solid-state fermentation. *Biochem. Eng. J.* **2020**, *161*, 107644. [CrossRef]

158. Rodríguez, P.; Cerda, A.; Font, X.; Sánchez, A.; Artola, A. Valorisation of biowaste digestate through solid state fermentation to produce biopesticides from *Bacillus thuringiensis*. *Waste Manag.* **2019**, *93*, 63–71. [CrossRef] [PubMed]

159. Sen, R.; Ishak, H.D.; Estrada, D.; Dowd, S.E.; Hong, E.; Mueller, U.G. Generalized antifungal activity and 454-screening of *Pseudonocardia* and *Amycolatopsis* bacteria in nests of fungus-growing ants. *Proc. Natl. Acad. Sci. USA* **2009**, *106*, 17805–17810. [CrossRef]

160. Rumbos, C.I.; Athanassiou, C.G. Use of entomopathogenic fungi for the control of stored-product insects: Can fungi protect durable commodities? *J. Pest. Sci.* **2017**, *90*, 839–854. [CrossRef]

161. Vassilakos, T.N.; Athanassiou, C.G.; Kavallieratos, N.G.; Vayias, B.J. Influence of temperature on the insecticidal effect of *Beauveria bassiana* in combination with diatomaceous earth against *Rhyzopertha dominica* and *Sitophilus oryzae* on stored wheat. *Biol. Control* **2006**, *38*, 270–281. [CrossRef]

162. Athanassiou, C.G.; Steenberg, T. Insecticidal effect of *Beauveria bassiana* (Balsamo) Vuillemin (*Ascomycota: Hypocreales*) in combination with three diatomaceous earth formulations against *Sitophilus granarius* (L.) (*Coleoptera: Curculionidae*). *Biol. Control* **2007**, *40*, 411–416. [CrossRef]

163. Michalaki, M.P.; Athanassiou, C.G.; Steenberg, T.; Buchelos, C. Effect of *Paecilomyces fumosoroseus* (Wise) Brown and Smith (*Ascomycota: Hypocreales*) alone or in combination with diatomaceous earth against *Tribolium confusum* Jacquelin du Val (Coleoptera: Tenebrionidae) and *Ephestia kuehniella* Zeller (Lepidoptera: Pyralidae). *Biol. Control* **2007**, *40*, 280–286. [CrossRef]

164. Michalaki, M.; Athanassiou, C.G.; Kavallieratos, N.G.; Batta, Y.A.; Balotis, G.N. Effectiveness of *Metarhizium anisopliae* (Metschinkoff) Sorokin applied alone or in combination with diatomaceous earth against *Tribolium confusum* Jacquelin du Val: Influence of temperature, relative humidity and type of commodity. *Crop Prot.* **2006**, *25*, 418–425. [CrossRef]

165. Lopez, M.G.; Diez, M.; Alfonso, V.; Taboga, O. Biotechnological applications of occlusion bodies of Baculoviruses. *Appl. Microbiol. Biotechnol.* **2018**, *102*, 6765–6774. [CrossRef] [PubMed]

166. Abbaszadeh, G.; Dhillon, M.K.; Srivastava, C.; Gautam, R.D. Effect of climatic factors on bioefficacy of biopesticides in insect pest management. *Biopestic. Int.* **2011**, *7*, 1–4.

167. Mounsef, J.R.; Salameh, D.; Brandam, C.; Lteif, R. Evaluation of a cereal milling byproduct for the low-cost production of *Bacillus thuringiensis* kurstaki in submerged fermentation. *European J. Biotechnol. Biosci.* **2014**, *6*, 10–16.
168. Şahin, B.; Gomis-Cebolla, J.; Güneş, H.; Ferre, J. Characterization of *Bacillus thuringiensis* isolates by their insecticidal activity and their production of Cry and Vip3 proteins. *PLoS ONE* **2018**, *13*, e0206813. [CrossRef]

169. Opisa, S.; Du Plessis, H.; Akutse, K.S.; Fiaboe, K.K.; Ekesi, S. Effects of Entomopathogenic fungi and *Bacillus thuringiensis*-based biopesticides on *Spolaea recurvalis* (Lepidoptera: Crambidae). *J. Appl. Entomol.* **2018**, *142*, 617–626. [CrossRef]

170. Yilmaz, S.; Karabörklü, S.; Azizoğlu, U.; Ayvaz, A.; Akbulut, M.; Yildiz, M. Toxicity of native *Bacillus thuringiensis* isolates on the larval stages of pine processionary moth *Thaumetopoea wilkinsoni* at different temperatures. *Turk. J. Agric. For.* **2013**, *37*, 163–172. [CrossRef]

171. Lacey, L.A.; Arthurs, S.P.; Knightm, A.L.; Huber, J. Microbial control of lepidopteran pests of apple orchards. In *Field Manual of Techniques in Invertebrate Pathology*; Springer: Dordrecht, The Netherlands, 2007; pp. 528–546. [CrossRef]

172. Walker, G.P.; Cameron, P.J.; MacDonald, F.M.; Madhusudhan, V.V.; Wallace, A.R. Impacts of *Bacillus thuringiensis* toxins on parasitoids (Hymenoptera: Braconidae) of *Spodoptera litura* and *Helicoverpa armigera* (Lepidoptera: Noctuidae). *Biol. Control* **2007**, *40*, 142–151. [CrossRef]

173. Soonsanga, S.; Rungrod, A.; Audtho, M.; Promdonkoy, B. *Tyrosine*-776 of Vip3Aa64 from *Bacillus thuringiensis* is important for retained larvicidal activity during high-temperature storage. *Curr. Microbiol.* **1999**, *3*, 15–21. [CrossRef]

174. Jackson, M.A. Dissolved oxygen levels affect dimorphic growth by the entomopathogenic fungus *Isaria fumosorosea*. *Biocontrol. Sci. Technol.* **2012**, *22*, 67–79. [CrossRef]

175. Sachdeva, V.; Tyagi, R.D.; Valero, J.R. Factors affecting the production of *Bacillus thuringiensis* bioinsecticides. *Rec. Res. Dev. Microbiol.* **1999**, *3*, 363–375.

176. Shojaaddini, M.; Moharramipour, S.; Khodabandeh, M.; Talebi, A. Development of a cost effective medium for production of *Bacillus thuringiensis* bioinsecticide using food barley. *J. Plant Protect Res.* **2010**, *50*, 9–14. [CrossRef]

177. Poopathi, S.; Abidha, S. A medium for the production of biopesticides (*Bacillus sphaericus* and *Bacillus thuringiensis* subsp. israelensis) in mosquito control. *J. Econ. Entomol.* **2009**, *102*, 1423–1430. [CrossRef]

178. Saksinchai, S.; Suphantharika, M.; Verduyn, C. Application of a simple yeast extract from spent brewer's yeast for growth and sporulation of *Bacillus thuringiensis* subsp kurstaki: A physiological study. *World J. Microbiol. Biot.* **2001**, *17*, 307–316. [CrossRef]

179. Adams, T.T.; Eiteman, M.A.; Adang, M.J. *Bacillus thuringiensis* subsp. kurstaki spore production in batch culture using broiler litter extracts as complex media. *Bioresour. Technol.* **1999**, *67*, 83–87. [CrossRef]

180. Alves, L.; Alves, S.; Pereira, R.; Capalbo, D. Production of *Bacillus thuringiensis* Berliner var. *kurstaki* grown in alternative media. *Biocontrol. Sci. Technol.* **1997**, *7*, 377–384. [CrossRef]

181. Barbosa, C.; Fernandes, A.; Berbert-Molina, M.; Boniolo, F.; Rossi, A.; Prata, A. Growth of *Bacillus thuringiensis* var. israelensis in glycerol derived from biodiesel industry aiming the production of bioinsecticide. *New Biotechnol.* **2009**, *25*, 227. [CrossRef]

182. Prabakaran, G.; Balaraman, K. Development of a cost-effective medium for the large-scale production of *Bacillus thuringiensis* var israelensis. *Biol. Control* **2006**, *36*, 288–292. [CrossRef]

183. Zouari, N.; Ali, S.B.S.; Jaoua, S. Production of delta-endotoxins by *Bacillus thuringiensis* strains exhibiting various insecticidal activities towards Lepidoptera and diptera in gruel and fish meal media. *Enzyme Microb. Technol.* **2002**, *31*, 411–418. [CrossRef]

184. Moreira, G.A.; Micheloud, A.J.; Beccaria, H.C. Goicoechea, Optimization of the *Bacillus thuringiensis* var. kurstaki HD-1 delta-endotoxins production by using experimental mixture design and artificial neural networks. *Biochem. Eng. J.* **2007**, *35*, 48–55. [CrossRef]

185. Ndao, A.; Sellamuthu, B.; Gnepe, J.R.; Tyagi, R.D.; Valero, J.R. Pilot-scale biopesticide production by *Bacillus thuringiensis* subsp. *kurstaki* using starch industry waste water as raw material. *J. Environ. Sci. Health B* **2017**, *52*, 623–630. [CrossRef]

186. Kumar, L.R.; Ndao, A.; Valéro, J.; Tyagi, R.D. Production of *Bacillus thuringiensis* based biopesticide formulation using starch industry wastewater (SIW) as substrate: A techno-economic evaluation. *Bioresour. Technol.* **2019**, *294*, 122–144. [CrossRef] [PubMed]

187. Kumar, S.P.J.; Kumar, N.S.S.; Chintagunta, A.D. Bioethanol production from cereal crops and lignocelluloses rich agro-residues: Prospects and challenges. *SN Appl. Sci.* **2020**, *2*, 1673. [CrossRef]

188. Zhuang, L.; Zhou, S.; Wang, Y.; Liu, Z.; Xu, R. Cost-effective production of *Bacillus thuringiensis* biopesticides by solid-state fermentation using waste water sludge: Effects of heavy metals. *Bioresour. Technol.* **2011**, *102*, 4820–4826. [CrossRef]

189. Zhang, W.; Zou, H.; Jiang, L.; Yao, J.; Liang, J.; Wang, Q. Semi-solid state fermentation of food waste for production of *Bacillus thuringiensis* biopesticide. *Biotechnol. Bioproc.* **2015**, *E20*, 1123–1132. [CrossRef]

190. Raheem, A.; Sikarwar, V.S.; He, J.; Dastyar, W.; Dionysiou, D.D.; Wang, W.; Zhao, M. Opportunities and challenges in sustainable treatment and resource reuse of sewage sludge: A review. *Chem. Eng. J.* **2018**, *337*, 616–641. [CrossRef]

191. Sivakalai, S.; Ramanathan, N. Simple and cost-effective method for mass production of entomopathogenic fungi by using naturally available substrate. *Int. J. Front. Sci. Technol.* **2015**, *2*, 67–77.

192. Kassa, A.; Brownbridge, M.; Parker, B.L.; Skinner, M.; Gouli, V.; Gouli, S.; Hata, T. Whey for mass production of *Beauveria bassiana* and *Metarhizium anisopliae*. *Mycol. Res.* **2008**, *112*, 583–591. [CrossRef]

193. Song, M.H.; Yu, J.S.; Kim, S.; Lee, S.J.; Kim, J.C.; Nai, Y.S.; Shin, T.Y.; Kim, J.S. Downstream processing of *Beauveria bassiana* and *Metarhizium anisopliae*-based fungal biopesticides against *Riptortus pedestris*: Solid culture and delivery of conidia. *Biocontrol Sci. Technol.* **2019**, *29*, 514–532. [CrossRef]

194. Kim, J.C.; Lee, M.R.; Kim, S.; Lee, S.J.; Park, S.E.; Baek, S.; Gasmi, L.; Shin, T.Y.; Kim, J.S. Long-term storage stability of *Beauveria bassiana* ERL836 granules as fungal biopesticide. *J. Asia-Pac. Entomol.* **2019**, *22*, 537–542. [CrossRef]
195. Barbadikar, K.M.; Aglawe, S.B.; Mangrauthia, S.K.; SeshuMadhav, M.; Jeevan Kumar, S.P. Genome editing: New breeding technologies in plants. In *OMICS-Based Approaches in Plant Biotechnology*; Banerjee, R., Kumar, G.V., Kumar, S.P.J., Eds.; Wiley-Scrivener Publishers: Hoboken, NJ, USA, 2019; pp. 247–285. [CrossRef]

196. Zhu, L.; Chu, Y.; Zhang, B.; Yuan, X.; Wang, K.; Liu, Z.; Sun, M. Creation of an industrial *Bacillus thuringiensis* strain with high melanin production and UV tolerance by gene editing. *Front. Microbiol.* **2022**, *13*, 913715. [CrossRef]

197. Vahed, M.; Motalebi, E.; Rigi, G.; Akbari Noghabi, K.; Soudi, M.R.; Sadeghi, M.; Ahmadian, G. Improving the chitinolytic activity of *Bacillus pumilus* SG2 by random mutagenesis. *J. Microbiol. Biotechnol.* **2013**, *23*, 1519–1528. [CrossRef] [PubMed]

198. Liu, K.; Hu, H.; Wang, W.; Zhang, X. Genetic engineering of *Pseudomonas chlororaphis* GP72 for the enhanced production of 2-hydroxyphenazine. *Microb. Cell Fact.* **2016**, *15*, 131. [CrossRef]

199. Tijerino, A.; Cardoza, R.E.; Moraga, J.; Malmierca, M.G.; Vicente, F.; Aleu, J.; Collado, I.G.; Gutikrrez, S.; Monte, E.; Hermosa, R. Overexpression of the trichodiene synthase gene tri5 increases trichodermin production and antimicrobial activity in *Trichoderma brevicompactum*. *Fungal Genet. Biol.* **2011**, *48*, 285–296. [CrossRef] [PubMed]

200. Jin, K.; Peng, G.; Liu, Y.; Xia, Y. The acid trehalase, ATM1, contributes to the in vivo growth and virulence of the entomopathogenic fungus, *Metarhizium acridum*. *Fungal Genet. Biol.* **2015**, *77*, 61–67. [CrossRef]

201. Slininger, P.; Burkhead, K.; Schisler, D.; Bothast, R.J. Isolation, identification, and accumulation of 2-acetamidophenol in liquid cultures of the wheat take-all biocontrol agent *Pseudomonas fluorescens* 2-79. *Appl. Microbiol. Biotechnol.* **2000**, *54*, 376–381. [CrossRef]

202. Timofeev, S.; Mitina, G.; Rogozhin, E.; Dolgikh, V. Expression of spider toxin in entomopathogenic fungus *Lecanicillium muscarium* and selection of the strain showing efficient secretion of the recombinant protein. *FEMS Microbiol. Lett.* **2019**, *366*, 181. [CrossRef]

203. Sarwar, M. Microbial insecticides-an ecofriendly effective line of attack for insect pest management. *Int. J. Eng. Adv. Res. Technol.* **2015**, *1*, 4–9.

204. Pava-Ripoll, M.; Posada, F.J.; Momen, B.; Wang, C.; St Leger, R. Increased pathogenicity against coffee berry borer, *Hypothenemus hampei* (Coleoptera: Curculionidae) by *Metarhizium anisopliae* expressing the scorpion toxin (AaIT) gene. *J. Invertebr. Pathol.* **2008**, *99*, 220–226. [CrossRef]

205. Wang, C.; St Leger, R.J. A scorpion neurotoxin increases the potency of a fungal insecticide. *Nat. Biotechnol.* **2007**, *25*, 1455. [CrossRef] [PubMed]

206. Xie, M.; Zhang, Y.J.; Zhai, X.M.; Zhao, J.J.; Peng, D.L.; Wu, G. Expression of a scorpion toxin gene BmKit enhances the virulence of *Lecanicillium lecanii* against aphids. *J. Pest. Sci.* **2015**, *88*, 637–644. [CrossRef]

207. Zhao, J.; Yao, R.; Wei, Y.; Huang, S.; Keyhani, N.O.; Huang, Z. Screening of *Metarhizium anisopliae* UV-induced mutants for faster growth yields a hyper-virulent isolate with greater UV and thermal tolerances. *Appl. Microbiol. Biotechnol.* **2016**, *100*, 9217–9228. [CrossRef]

208. Sinha, R.P.; Häder, D.P. UV-induced DNA damage and repair: A review. *Photo Chem. Photo Boil. Sci.* **2002**, *1*, 225236. [CrossRef]

209. Fang, W.; St. Leger, R.J. Enhanced UV resistance and improved killing of malaria mosquitoes by photolyase transgenic entomopathogenic fungi. *PLoS ONE* **2012**, *7*, e43069. [CrossRef] [PubMed]

210. Haas, D.; Keel, C.; Laville, J.; Maurhofer, M.; Oberhansli, T.; Schnider, U.; Voisard, C.; Wuthrich, B.; Defago, G. Secondary metabolites of *Pseudomonas fluorescens* strain CHAO involved in the suppression of root diseases. In *Advances in Molecular Genetics of Plant-Microbe Interactions*; Hennecke, H., Verma, D.P.S., Eds.; Kluwer Academic Publishers: Dordrecht, The Netherlands, 1990; Volume I, pp. 450–456. [CrossRef]

211. Koul, O. Microbial biopesticides: Opportunities and challenges. Reviews: Perspectives in agriculture, veterinary science, nutrition and natural resources. *CAB Rev.* **2011**, *6*, 1–26. [CrossRef]

212. Pazmiño-Ibarra, V.; Mengual-Martí, A.; Targovnik, A.M.; Herrero, S. Improvement of baculovirus as protein expression vector and as biopesticide by CRISPR/Cas9 editing. *Biotechnol. Bioeng.* **2019**, *116*, 2823–2833. [CrossRef]

213. Wang, J.; Zuo, Y.Y.; Li, L.L.; Wang, H.; Liu, S.Y.; Yang, Y.H.; Wu, Y.D. Knockout of three aminopeptidase N genes does not affect susceptibility of *Helicoverpa armigera* larvae to *Bacillus thuringiensis* Cry1A and Cry2A toxins. *Insect Sci.* **2020**, *7*, 440–448. [CrossRef]

214. Devi, S.; Karsauliya, K.; Srivastava, T.; Raj, R.; Kumar, D.; Priya, S. Pesticide interactions induce alterations in secondary structure of malate dehydrogenase to cause destabilty and cytotoxicity. *Chemosphere* **2021**, *263*, 128074. [CrossRef]

215. Gao, P.; Qi, K.; Han, Y.; Ma, L.; Zhang, B.; Zhang, Y.; Guan, X.; Qi, J. Effect of *Trichoderma viride* on rhizosphere microbial communities and biocontrol of soybean root rot. *Front. Microbiol.* **2023**, *14*, 1204688. [CrossRef]

216. Campos, M.; Jacobs-Wagner, C.; Strobel, S.A. Mycofumigation by the volatile organic compound-producing fungus *Muscodor albus* induces bacterial cell death through DNA damage. *Appl. Environ. Microbiol.* **2015**, *81*, 1147–1156. [CrossRef]

217. Jain, P.; Pundir, R.K. Production of antimicrobial substances from endophytic microorganisms: Potential applications as biocontrol agents in agriculture. In *Antimicrobials in Agriculture*; CRC Press: Boca Raton, FL, USA, 2024; pp. 85–95. [CrossRef]

218. Mudrončeková, S.; Mazáň, M.; Nemčovič, M.; Šalamon, I. Entomopathogenic fungus species *Beauveria bassiana* (Bals.) and *Metarhizium anisopliae* (Metsch.) used as mycoinsecticide effective in biological control of *Ips typographus* (L.). *J. Microbiol. Biotechnol. Food Sci.* **2019**, *2*, 2469–2472.

219. Hubbard, M.; Hynes, R.K.; Erlandson, M.; Bailey, K.L. The biochemistry behind biopesticide efficacy. *Sustain. Chem. Process.* **2014**, *2*, 18. [CrossRef]
220. Çaldaş, A.; Börçek Kasurka, C.; Ertürk, Ö. Effects of wasp (Vespa crabro) nest extracts on virus replication of Autographa californica nuclear polyhedrosis virus on Spodoptera frugiperda cell culture. *Cytotechnology* **2024**, *76*, 123–137. [CrossRef] [PubMed]

221. Gómez-Bonilla, Y.; López-Ferber, M.; Caballero, P.; Murillo, R.; Muñoz, D. Granulovirus formulations efficiently protect stored and field potatoes from Phthorimaea operculella and Tecia solanivora in Costa Rica. *BioControl* **2013**, *58*, 215–224. [CrossRef]

222. Majić, I.; Sarajlić, A.; Lakatos, T.; Toth, T.; Raspudić, E.; Puškadija, Z.; Šarić, G.K.; Laznik, Ž. Virulence of new strain of *Heterorhabditis bacteriophora* from Croatia against *Lasioptera rubi*. *Plant Protect. Sci.* **2019**, *55*, 134–141. [CrossRef]

223. Ryu, K.G.; Bae, J.S.; Yu, Y.S.; Park, S.H. Insecticidal toxin from *Xenorhabdus nematophilus*, symbiotic bacterium associated with entomopathogenic nematode *Steinernema glaseri*. *Biotechnol. Bioprocess. Eng.* **2000**, *5*, 141–145. [CrossRef]

224. Liu, H.; Zeng, H.; Yao, Q.; Yuan, J.; Zhang, Y.; Qiu, D.; Yang, X.; Yang, H.; Liu, Z. *Steinernema glaseri* surface enolase: Molecular cloning, biological characterization, and role in host immune suppression. *Mol. Biochem. Parasit.* **2012**, *185*, 89–98. [CrossRef]

225. Shehata, I.E.; Hammam, M.M.; Abd-Elgawad, M.M. Effects of inorganic fertilizers on virulence of the entomopathogenic nematode *Steinernema glaseri* and peanut germination under field conditions. *Agronomy* **2021**, *11*, 945. [CrossRef]

226. Zhang, L.; Lecoq, M. *Nosema locustae* (Protozoa, Microsporidia), a biological agent for locust and grasshopper control. *Agronomy* **2021**, *11*, 711. [CrossRef]

227. Grushevaya, I.V.; Ignatieva, A.N.; Malыш, S.M.; Senderskiy, I.V.; Zubarev, I.V.; Kononchuk, A.G. Spore dimorphism in *Nosema pyrausta* (Microsporidia, Nosematidae): From morphological evidence to molecular genetic verification. *Acta Protozool.* **2018**, *57*, 49–52. [CrossRef]

228. Vavra, J.; Hylis, M.; Vossbrinck, C.R.; Pilarska, D.K.; Linde, A.; Weiser, J.; McManus, M.L.; Hoch, G.; Solter, L.F. *Vairimorpha disparis* n. comb. (Microsporidia: Burenellidae): A redescription and taxonomic revision of *Thelohania disparis* Timofejeva 1956, a microsporidian parasite of the gypsy moth *Lymantria dispar* (L.) (Lepidoptera: Lymantriidae). *J. Eukaryot.* *Microbiol.* **2006**, *53*, 292–304. [CrossRef] [PubMed]

229. Palma, L.; Muñoz, D.; Berry, C.; Murillo, J.; Caballero, P. *Bacillus thuringiensis* toxins: An overview of their biocidal activity. *Toxins* **2014**, *6*, 3296–3325. [CrossRef]

230. Melo, A.L.; Soccol, V.T.; Soccol, C.R. *Bacillus thuringiensis*: Mechanism of action, resistance, and new applications: A review. *Crit. Rev. Biotechnol.* **2016**, *36*, 317–326. [CrossRef] [PubMed]

231. Subbanna, A.R.; Rajasekhara, H.; Stanley, J.; Mishra, K.K.; Pattanayak, A. Pesticidal prospectives of chitinolytic bacteria in agricultural pest management. *Soil. Biol. Biochem.* **2018**, *116*, 52–66. [CrossRef]

232. Swiontek Brzezinska, M.; Jankiewicz, U.; Kalwasińska, A.; Świączak, J.; Żero, K. Characterization of chitinase from *Streptomyces luridiscabiei* U05 and its antagonist potential against fungal plant pathogens. *J. Phytopathol.* **2019**, *167*, 404–412. [CrossRef]

233. Anees, M.; Abid, M.; ur Rehman, S.; Ahmed, N.; Ashraf, M.; Zhang, L.; Kim, K.Y. Antifungal activity of various chitinolytic bacteria against *Colletotrichum* in pepper. *Plant Protect. Sci.* **2019**, *55*, 109–115. [CrossRef]

234. Chen, K.N.; Chen, C.Y.; Lyn, Y.C.; Chen, M.J. Formulation of a novel antagonistic bacterium based biopesticide for fungal disease control using microencapsulation techniques. *J. Agric. Sci.* **2013**, *5*, 153–163. [CrossRef]

235. Syahri, R.U.S. Will biopesticides arise in pesticide nanoformulations? Current and future prospective bibliometric evaluation. *AIP Conf. Proc.* **2024**, *3058*, 030001. [CrossRef]

236. Foreverest. Biopesticide Development, Registration, and Commercial Formulations. 2018. Available online: https://foreverest. cn/news-list/biopesticide-development-registration-and-commercial-formulations (accessed on 18 July 2023).

237. Dhakal, R.; Singh, D.N. Biopesticides: A key to sustainable agriculture. *Int. J. Pure Appl. Biosci.* **2019**, *7*, 391–396. [CrossRef]

238. Knowles, A. Recent developments of safer formulations of agrochemicals. *Environmentalist* **2008**, *28*, 35–44. [CrossRef]

239. Heijnen, C.E.; Burgers, S.L.; Van Veen, J.A. Metabolic activity and population dynamics of rhizobia introduced into unamended and bentonite-amended loamy sand. *Appl. Environ. Microbiol.* **1993**, *59*, 743–747. [CrossRef] [PubMed]

240. Anitha, A.; Rabeeth, M. Control of Fusarium wilt of tomato by bioformulation of *Streptomyces griseus* in green house condition. *Afr. J. Basic. Appl. Sci.* **2009**, *1*, 9–14.

241. Meena, B. Survival and effect of *Pseudomonas fluorescens* formulation developed with various carrier materials in the management of late leaf spot of groundnut. *Int. J. Plant Prot.* **2010**, *3*, 200–202.

242. Mohanraj, P.; Mahalingam, C.A.; Raghuchander, R. Development of bioformulation and its application against management of thrips and root rot disease of mulberry, *Morus alba*. *Int. J. Curr. Microbiol. App. Sci.* **2017**, *6*, 2438–2449. [CrossRef]

243. Swami, D.; Paul, B.; Dotasara, S.K. Effect of carriers on the efficacy of *Bacillus thuringiensis* Var. *Kurstaki* (Hd-1) formulations. *Pestic. Res. J.* **2017**, *19*, 88–92.

244. Reddy, P.P. Mass production, formulation, delivery and commercialization. In *Plant Growth Promoting Rhizobacteria for Horticultural Crop Protection*; Springer: New Delhi, India, 2014; pp. 69–83.

245. Costa, J.A.; Freitas, B.C.; Cruz, C.G.; Silveira, J.; Morais, M.G. Potential of microalgae as biopesticides to contribute to sustainable agriculture and environmental development. *J. Environ. Sci. Health B* **2019**, *54*, 366–375. [CrossRef]

246. Mackie, A.R.; Macierzanka, A.; Aarak, K.; Rigby, N.M.; Parker, R.; Channell, G.A.; Harding, S.E.; Bajka, B.H. Sodium alginate decreases the permeability of intestinal mucus. *Food Hydrocoll.* **2016**, *52*, 749–755. [CrossRef]

247. Rao, M.S.; Umamaheswari, R.; Chakravarthy, A.K.; Grace, G.N.; Kamalnath, M.; Prabu, P. A frontier area of research on liquid biopesticides: The way forward for sustainable agriculture in India. *Curr. Sci.* **2015**, *108*, 1590–1592.

248. Pilarska, D.; Takov, D.; Hylis, M.; Radek, R.; Fiala, I.; Solter, L.; Linde, A. Natural occurrence of microsporidia infecting Lepidoptera in Bulgaria. *Acta Parasitol.* **2017**, *62*, 858–869. [CrossRef]
249. Devrnja, N.; Andelković, B.; Ljujić, J.; Ćosić, T.; Stupar, S.; Milutinović, M.; Savić, J. Encapsulation of fennel and basil essential oils in β-Cyclodextrin for novel biopesticide formulation. *Biomolecules* **2024**, *14*, 353. [CrossRef] [PubMed]

250. Fillinger, S.; Chaveroche, M.K.; Van Dijck, P.; de Vries, R.; Ruijter, G.; Thevelein, J.; d'Enfert, C. Trehalose is required for the acquisition of tolerance to a variety of stresses in the filamentous fungus. *Microbiology* **2001**, *147*, 1851–1862. [CrossRef] [PubMed]

251. Pindi, P.K.; Satyanarayana, S. Liquid microbial consortium-a potential tool for sustainable soil health. *J. Biofertil. Biopestici.* **2012**, *3*, 1000124. [CrossRef]

252. Odoh, C.K.; Sam, K.; Zabbey, N.; Eze, C.N.; Nwankwegu, A.S.; Laku, C.; Dumpe, B.B. Microbial consortium as biofertilizers for crops growing under the extreme habitats. In *Plant Microbiomes for Sustainable Agriculture*; Springer: Cham, Switzerland, 2020; pp. 381–424. [CrossRef]

253. Chintagunta, A.D.; Kumar, A.; Jeevan Kumar, S.P.; Verma, M.L. Contribution of metallic nanomaterials in algal biofuel production. In *Metal and Metal Oxides for Energy and Electronics. Environmental Chemistry for a Sustainable World*; Rajendran, S., Qin, J., Gracia, F., Lichtfouse, E., Eds.; Springer: Cham, Switzerland, 2021; Volume 55, pp. 331–353. [CrossRef]

254. Manikandan, R.; Saravanakumar, D.; Rajendran, L.; Raguchander, T.; Samiyappan, R. Standardization of liquid formulation of *Pseudomonas fluorescens* Pfl for its efficacy against *Fusarium* wilt of tomato. *Biol. Control* **2010**, *54*, 83–89. [CrossRef]

255. Gupta, A.; Rayeen, F.; Mishra, R.; Tripathi, M.; Pathak, N. Nanotechnology applications in sustainable agriculture: An emerging eco-friendly approach. *Plant Nano Biol.* **2023**, *4*, 100033. [CrossRef]

256. Fallah, Z.; Zare, E.N.; Ghomi, M.; Ahmadijokani, F.; Amini, M.; Tajbakhsh, M.; Arjmand, M.; Sharma, G.; Ali, H.; Ahmad, A.; et al. Toxicity and remediation of pharmaceuticals and pesticides using metal oxides and carbon nanomaterials. *Chemosphere* **2021**, *275*, 130055. [CrossRef]

257. Khot, R.; Sankaran, S.; Maja, J.M.; Ehsani, R.; Schuster, E.W. Applications of nanomaterials in agricultural production and crop protection: A review. *Crop Prot.* **2012**, *35*, 64–70. [CrossRef]

258. Agrawal, S.; Rathore, P. Nanotechnology pros and cons to agriculture: A review. *Int. J. Curr. Microbiol. Appl. Sci.* **2014**, *3*, 43–55.

259. Bharati, A.P.; Kumar, A.; Kumar, S.; Maurya, D.K.; Kumari, S.; Agarwal, D.K.; Kumar, S.J. Role of biotechnology in the exploration of soil and plant microbiomes. In *Phytobiomes: Current Insights and Future Vistas*; Solanki, M., Kashyap, P., Kumari, B., Eds.; Springer: Singapore, 2020; pp. 335–355. [CrossRef]

260. Verma, M.L. Enzymatic nanobiosensors in the agricultural and food industry. In *Nanoscience in Food and Agriculture 4. Sustainable Agriculture Reviews*; Ranjan, S., Dasgupta, N., Lichtfouse, E., Eds.; Springer: Cham, Switzerland, 2017; Volume 24. [CrossRef]

261. Chamundeeswari, M.; Jeslin, J.; Verma, M.L. Nanocarriers for drug delivery applications. *Environ. Chem. Lett.* **2018**, *17*, 849–865. [CrossRef]

262. Saravanan, A.; Senthil Kumar, P.; Govarthanan, M.; George, C.S.; Vaishnavi, S.; Moulishwaran, B.; Praveen Kumar, S.; Jeevanantham, S.; Yaashikaa, P.R. Adsorption characteristics of magnetic nanoparticles coated mixed fungal biomass for toxic Cr (VI) ions in aquatic environment. *Chemosphere* **2021**, *267*, 129226. [CrossRef]

263. Damalas, C.A.; Koutroubas, S.D. Current status and recent developments in biopesticide use. *Agriculture* **2018**, *8*, 13. [CrossRef]

264. Bonaterra, A.; Badosa, E.; Cabrefiga, J.; Frances, J.; Montesinos, E. Prospects and limitations of microbial pesticides for control of bacterial and fungal pomefruit tree diseases. *Trees* **2011**, *26*, 215–226. [CrossRef]

265. Verma, M.L.; Barrow, C.J.; Puri, M. Nanobiotechnology as a novel paradigm for enzyme immobilization and stabilisation with potential applications in biofuel production. *Appl. Microbiol. Biotechnol.* **2013**, *97*, 23–39. [CrossRef] [PubMed]

266. Prasad, R.; Bhattacharyya, A.; Nguyen, Q.D. Nanotechnology in sustainable agriculture: Recent developments, challenges, and perspectives. *Front. Microbiol.* **2017**, *8*, 1014. [CrossRef] [PubMed]

267. Olson, S. An analysis of the biopesticide market now and where is going. *Outlooks Pest. Manag.* **2015**, *26*, 203–206. [CrossRef]

268. Kumar, S.; Singh, A. Biopesticides: Present status and the future prospects. *J. Fertil. Pestic.* **2015**, *6*, e129. [CrossRef]

269. Isman, M.B. A renaissance for botanical insecticides? *Pest Manag. Sci.* **2015**, *71*, 1587–1590. [CrossRef]

270. Singh, R.P.; Chintagunta, A.D.; Agarwal, D.K.; Kureel, R.S.; Kumar, S.P.J. Varietal replacement rate: Prospects and challenges for global food security. *Glob. Food Sec.* **2021**, *2021*, 100324. [CrossRef]