Background Chitin, a long-chain polymer of N-acetylglucosamine, is a major structural component of the insect exoskeleton and the peritrophic membrane (PM). Chitinases are able to effectively break down glycosidic bonds of chitin polymer thus can be used in agriculture to control plant pathogen insects. These enzymes can be synthesized by higher plants, animals, protista, bacteria, and viruses. Results In this study, viral and bacterial chitinases were compared for their potential activity on a laboratory test insect. The genes encoding chitinases of Autographa californica nucleopolyhedrovirus (AcNPV) and Cydia pomonella granulovirus (CpGV) were amplified from genomic DNAs by PCR and cloned into the pET-28a (+) expression vector. The chitinase proteins of these 2 viruses (AcNPV-Chi, CpGV-Chi) and Serratia marcescens chitinase C (ChiC) protein which was previously cloned were overexpressed in Escherichia coli. Expressed proteins were purified and confirmed by western blot analysis as 50, 63, and 68 kDa for AcNPV, CpGV, and S. marcescens chitinases, respectively. Enzyme activities of the chitinases were confirmed. Chitinases were also compared to each other in silico. The insecticidal effects of these proteins were evaluated on Galleria mellonella L. larvae. Bioassays were performed on the 3rd instar larvae for each chitinase protein in triplicate. The results showed that although there were differences in enzymatic activities and domain organizations, all 3 microbial chitinases produced almost the same level of insecticidal activity on the test insect. LC50 and LT50 values were compatible with the mortality results. These results were a preanalysis for comparing the effects of microbial chitinases. Conclusion Potential activity experiments should be carried out on more insects to provide detailed information on the insecticidal effects of bacterial and viral chitinases.

Background The importance of bees for environmental health is known. Within the scope of this importance, it is of great importance to protect the health of bees and to prevent colony extinction. In this context, it is very important to develop effective methods in combating microorganisms, parasitoids, mites and organisms that cause disease or harm in bees. Both use different methods in terms of bee health. Result In this study, the possibility of the bacteria isolated from Varroa destructor mite being bioinsecticide was investigated. Accordingly, six bacteria were isolated from the mite. Isolated bacteria were analyzed according to biochemical tests, molecular analysis, optimum growth pH and phylogenetic tree drawn as Pantoea dispersa (GV1), Lysinibacillus macroides (GV3), Bacillus mycoides (GV4), Lysinibacillus fusiformis (GV5), Pseodomonas lutea (GV5), Lysinibacillus varians (GV7). Lysinibacillus sp. The entomopathogenic feature of Lysinibacillus sp. ranked it as the most important species. When the insecticidal properties of bacteria were examined, they were determined as 53, 90, 62, 95, 74 and 83% for GV1, GV3, GV4, GV5, GV6 and GV7, respectively. Conclusion Based on these results and literature review, Lysinibacillus sp. species had a high potential to be used as bioinsecticide against V. destructor mite.

Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae: Spilomelinae) is a primary pest on boxwood. The larvae of this pest cause damage by eating the leaves. They prevent the plant from performing photosynthesis, gnaw the bark of the shoots, damage the cambium layer and thus dry the boxwood shoots and branches. The boxwood moth, which is an exotic species in Türkiye, was first found in gardens and parks in Istanbul in 2011 and subsequently in Artvin and Düzce in 2015, and Bartın in 2016. The aim of this study is to develop a control method for this pest by considering the damage of the species. In this context, bacteria were isolated from the larvae collected from Artvin in May 2021 and bacteria screening was conducted to obtain an effective isolate. At the end of this isolation, Bacillus thuringiensis (Berliner, 1915) (Bacteria: Bacillaceae) was found. When cry gene analysis of this bacterium was performed, it was determined that it contained cry1, cry3 and cry4 genes. The insecticidal activity of this bacterium was tested on C. perspectalis and a mortality rate of 85% was obtained.

Beekeeping provides important contributions to the agricultural economy and crop production through pollination both in Turkey and the world. It is evaluated that without bees, the plant production can decrease by 47%. Many factors affect honey production negatively. Among these reasons, besides diseases caused by microorganisms, diseases and dangers originating from organisms are at the forefront. Today, many methods are used in the control these pests and yet they are still unavoidable. Among these methods, the biological control method is not used commonly. The aim of the study is to create a basis for the development of biopesticides to control bee diseases. In this context, as a result of the study, 16 bacteria were isolated from honey bees. While, 12 bacteria belonging to the genus Bacillus, two bacteria belonging to the genus Lysinibacillus, one bacterium belonging to the genus Paenibacillus and one bacterium belonging to the genus Pantoea were obtained. Molecular and biochemical identifications of these bacteria were done and registered in GenBank and their accession numbers were obtained. cry gene analyzes of 15 bacteria belonging to the genus Bacillus were performed. As it is known, cry genes have the potential to be used against pests. In the future, these bacteria and their genes will have the potential to be used as biopesticides. According to these results, the cry1 gene was observed in 8 bacteria and the cry3 gene was observed in 3 bacteria. cry2 and cry4 genes could not be detected in these bacteria. Bacteria that including cry genes are of great importance for honey bee health. Bacteria have the potential to be developed as internal biopesticides and used against different bee diseases to improve honey bee health.

Disaster is a natural, technological and human-based phenomenon that requires the coordination of many institutions and organisations and causes physical, economic and social losses for human rights, interrupts normal life and human activities. Biological disasters are situations caused by organic origin or biological carriers. These biological carriers can be disease-bearing microorganisms, toxins, and bioactive products. When this situations occur, many deaths can occur, as well as injuries, illness or health problems. Moreover, these biological factors can turn into agricultural production losses, pasture-grazing diseases, social and economic breakdowns or even an environmental disaster depending on the type. The emergence of all kinds of negative effects of pesticides, the abundance of natural enemies that can be exploited in nature and the increase of environmental awareness should be the reasons for focusing on an environmentally friendly, sustainable and cheap control method such as Biological Control. Entomopathogens used in biological control against insects include bacteria, fungi, viruses, protozoa and nematodes. In terms of biological disasters, insect infestation and epidemic diseases stand out among this group. The most important biological disasters are disasters caused by microorganisms, and COVID-19, which the whole world is trying to deal with today, is a global biological disaster. The epidemic started in Wuhan / China in late 2019 and is now spreading all over the world.