## 10 Conclusions and Future Prospects  
The ever-increasing world population is intensifying the demands on food production; however, this increase has to take place in parallel with a reduction in chemical inputs and in a scenario where biotic and abiotic stresses are constantly on the increase. This challenge is quite enormous and needs to be met by focusing efforts on new strategies. The industrial-scale rearing of insects has led to a significant increase in the generation of by-products that require valorization, particularly those with added value, such as insect grass. Due to its rich nutritional profile and diverse microbial content, frass holds great potential as a biofertilizer. Moreover, numerous studies have demonstrated its ability to enhance plant responses to both biotic and abiotic stresses. As highlighted in this review, the current scientific literature supports the beneficial effects of insect frass in mitigating various stress factors, from improving plant tolerance and salinity to exhibiting antifungal activity against plant diseases. However, some studies have also reported potential negative effects. Therefore, continued research is essential to better understand and mitigate these drawbacks, ensuring frass' safe and effective application in agriculture. For future research directions, it would be valuable to further investigate the mechanisms activated in plants upon the application of insect frass, as well as the metabolic pathways involved. Additionally, it is crucial to consider the practical application of frass in real-world agriculture and increase field trials to assess its functionality under natural conditions. Long-term studies on soil health are also necessary to determine the cumulative effects of frass application over time, particularly its influence on nutrient cycling, microbial communities, and soil structure. Furthermore, regulatory assessments should be conducted  
Figure 2: Summary infographic showing all the positive and negative effects of insect frass in its use in agriculture, in relation to abiotic and biotic plant stresses. to establish standardized guidelines for its use, ensuring both efficacy and safety while addressing potential concerns regarding contaminants or variability in frass composition. A deeper exploration of the microbial diversity associated with frass and its interactions with the existing soil microbiome is also needed to mitigate potential negative effects on crops and soil health. In summary, insect frass is a promising agricultural input with potential applications as a growth promoter and in mitigating both abiotic and biotic stresses, contributing to a more sustainable approach that reduces the reliance on chemical inputs in the field. This is particularly relevant given the increasing regulatory restrictions, which advocate for a gradual reduction in chemical usage. However, its application requires a thorough evaluation to prevent potential negative effects, ensure its safety and validate its effectiveness under real agricultural conditions. [PERSON] conceptualized and designed the manuscript. [PERSON] performed the bibliographic search and analyzed the information. [PERSON] and [PERSON] wrote the first version of the manuscript. [PERSON] elaborated the infographics. [PERSON], [PERSON], [PERSON] and [PERSON] contributed to the manuscript correction and critical reading. All authors have read and agreed to the published version of the manuscript. This publication is part of the R&D project \"PID2022-142403 OA-I00 (BIOCROPPING)\", funded by MCIN/AEI/10.13039/501100011033/FEDER, UE. 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.