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Fungal pathogens of Hypera postica(Gyllenhall) (Coleoptera: Curculionidae) were collected from the vicinities of Adana and Igdir in Turkey. The pathogenicity of the fungal isolates against the pest were investigated. According to morphologic (colony morphology, spore shape) and molecular (sequences of ITS1-5.8S ITS2 region and EF1-α, Bloc, and RPB1 genes) characterizations, the isolates were identified as Beauveria bassiana(HpI-2, HpI-6, HpI-7, HpI-10, HpA-3, HpA-4, HpA-5) and Beauveria pseudobassiana(HpI-4). All these strains were isolated from H. posticafor the first time. In order to determine pathogenesis of all isolates on the target pest, bioassays were conducted against larvae and adults, as screening of (1 × 107conidia/ml) and dose-response (1 × 105, 1 × 106, 1 × 107, 1 × 108, conidia/ml), under laboratory conditions. The fungal isolates, closely related to each other, yielded significantly varied mortalities on larvae and adults. H. posticalarvae were found more susceptible than adults to the fungal isolates in all tests. The highest mortality rates (100 and 98%) for larvae and adults, respectively, were obtained by B. bassianastrain HpA-5 within 14 days at 1 × 108conidia/ml concentration. The median lethal concentration (LD50) of HpA-5 required to kill the larvae and adults of H. posticaat concentrations of 2.37 × 104and 1.4 × 105conidia/ml, respectively. These results are promising; therefore, the B. bassianastrain HpA-5 can potentially be used against H. postica.

Background: The aim of this study was to develop an oil formulation from a local betabaculovirus. Hyphantria cuneaDrury (Lepidoptera: Erebidae) granulovirus (HycuGV-Hc1) was isolated from the infected larvae to test its efficacy on the pest. The oil formulation was prepared by mixing the viral suspension with sunflower oil and some adjuvants and named HycuGV-TR61. Crude virus and the formulations were carried out on third instar H. cunealarvae using 1 × 104–8OBs /ml concentrations and were exposed to temperatures (28, 35, and 42 °C) and UV-B light at different periods (0, 1, 3, 5 h). Results: The mortality rate, which was 50% at the lowest concentration (1 × 104OB/ml), reached 99.86% at the highest concentration (1 × 108OB/ml). LC50values of fresh and old forms were calculated as 0.64 × 104and 0.87 × 104OBs/ml, respectively. Application of shelf life showed that there was non-significant change in the pathogenic activity of the formulation with time. In the experiments, it was observed that the activity decreased as the temperature and time of exposure increased. Significantly difference in larval mortality was observed when fresh and old formulations were exposed to 0, 1, 3 and 5 h to UV-B, (old: 96.7, 86, 80 and 60%; fresh: 97.1, 90, 85 and 62%, respectively). Conclusions: The results revealed superior aspects of HycuGV-TR61, which was developed as a local viral biopesticide, its resistance to abiotic factors and its potential to be used in pest control.

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 marcescenschitinase 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. marcescenschitinases, 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 mellonellaL. 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. LC50and LT50values 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.