## 4 Discussion  
In this study, we confirmed that the loss of the symbiotic microbiota of the rice weevil caused a lethal effect, while the lesser grain borer, devoid of microbiota, showed a stable survival rate. It has also been proven that the lack of obligatory symbionts in the world of insects may cause, apart from the impaired utilization of nutrients, developmental impairment leading to death. Most of the research related to the role of the symbiotic microbiota concerns the gut microbiota and its important role in insect nutrition and immunology. A group of scientists [33] described the role of bacteria in the feeding of Asian long-horned beetle (_Anoplophora glabripennis_), which is an insect that feeds on the wood  
Figure 6: Heatmap showing the parameters of metabolism and enzymatic activity of the rice weevil microbiota and the lesser grain borer; So: _S. oryzae_, Rd: _R. domitica_, C: control, Bg: background, Ant: antibiotic, +: alive, -: dead. of deciduous trees. This insect is incapable of degrading lignin and efficiently releasing bioavailable sugars. Nevertheless, the microbiome in the insect's intestine facilitates this process by allowing the insect to eat the sugars it has released. This group of scientists sequenced the microbiome of the digestive system of _A. glabripennis_ and thus identified the genes of the microorganisms involved in the degradation of wood, including lignin. This group includes lactases, peroxididases, and \(\beta\)-esterases, as well as 36 families of glycosidic hydrolases, i.e., cellulases and xylanases, along with genes responsible for the bioavailability and increase in nutrient assimilation and their detoxification. In addition to the function of the microbiota, it is also important to pay attention to the taxonomic groups of symbiotic bacteria associated with insects. [PERSON] et al. [34] analyzed the intestinal microbiome of _Holotrichia parallels_ larvae, whose larvae feed in the soil and cause severe crop yield losses. Based on 16S rRNA, ARDRA (amplified ribosomal DNA restriction analysis) and biochemical tests, a cellulolytic bacterial community was identified (Proteobacteria (70.05%), followed by Actinobacteria (24.15%), Firmicutes (4.35%) and Bacteroidetes (1.45%), which included the following genera: _Pseudomonas_, _Chlorostrum_, _Rhizobium_, _Cellulosinicobium_, _Microbacterium_, _Bacillus_, _Dyadobacter_, _Siphonobacter_, _Paracoccus_, _Kaistia_, _Devosia_, _Labrys_, _Ensifer_, _Variorox_, _Shinella_, _Citrobacter_ and _Stentopomonas_). Like in the present study, it was observed that the Proteobacteria-order bacteria were the prevailing symbiotic microorganisms, regardless of their function. _Sodalis pirantinis_ was the eudominant species colonizing the digestive tract of the rice weevils. Among the microbiota considered to be rare, but having a significant share in the intestinal community, the following were also classified: _E. coli_, _Sodalis praceptivus_, _Klebsiella pneumoniae_, _Edwardsiella ictaluri_, and _Salmonella enterica_. The group of occasional species with a relatively high abundance included _Proteus mirabilis_, _Enterobacter hormoneachi_, _Pectobacterium carotovorum_, _Dickeya dianthicola_, and _Providencia rettergi_. These results clearly show that _Sodalis pierantinis_ colonized the gastrointestinal tract as the eudominant bacterium. The remaining taxa were small in number and belonged to Enterobacteriaceae, typical representatives of the intestinal microbiota and, interestingly, other representatives of Petobacteriaceae and _Proteus_ sp., whose importance in the digestive system is unknown. In turn, the _Sodalis_ spp. genus bacteria have been identified as free-living bacteria, and a large group of species and strains were classified as insect symbionts. There was considerable genetic variation at the genomic level between free-living and symbiotic _Sodalis_. It was shown that symbionts had characteristic features such as a smaller genome size or a large number of pseudogenes.