Deka, Mukul KumarRokozeno2023-12-142023-12-142020https://krishikosh.egranth.ac.in/handle/1/5810203059Field and laboratory experiments were carried out at the Department of Entomology and Department of Agricultural Biotechnology, Assam Agricultural University, Jorhat during 2018 and 2019 to study the management of greater wax moth, Galleria mellonella (Lepidoptera: Pyralidae), a serious pest of the honey bee using different integrated modules and to characterized the gut bacterial community. Different life stages of the wax moth were studied to provide a concise information on the population trend. Laboratory studies confirmed the occurrence of multiple generations of G. mellonella in a year. In the present study, five generations of G. mellonella were recorded in a single year. The duration of each developmental stages showed variation in each generation. Mean incubation period was found to be 4.60 ± 0.49 days (1st generation), 4.40 ± 0.49 days (2nd generation), 3.20 ± 0.40 days (3rd generation), 4.20 ± 0.75 days (4th generation) and 8.00 ± 0.63 days in the 5th generation. Throughout each generation a total 6 (six) numbers of larval instars were recorded. Mean duration of the total larval period was observed to be 32.40 ± 2.33 days (1st generation), 25.20 ± 0.40 days (2nd generation), 25.40 ± 1.62 days (3rd generation), 25.60 ± 1.36 days (4th generation) and 45.80 ± 1.17 days (5th generation). The mean duration of the pre- pupal period was recorded to be 5.20 ± 0.75 days (1st generation), 3.40 ± 0.49 days (2nd generation), 3.80 ± 0.75 days (3rd generation), 4.20 ± 0.40 days (4th generation) and 10.60 ± 0.80 days (5th generation). The mean duration of the pupal period was found to be 9.80 ± 1.17 days (1st generation), 9.60 ± 0.49 days (2nd generation), 8.00 ± 0.63 days (3rd generation), 8.60 ± 0.49 days (4th generation) and 18.00 ± 1.67 days in the last generation. The longevity of the male adult wax moth recorded a mean duration of 17.80 ± 0.75 days (1st generation), 20.60 ± 1.02 days (2nd generation), 20.20 ± 0.75 days (3rd generation), 21.40 ± 1.02 days (4th generation) and 8.40 ± 0.80 days (5th generation).The adults recorded a longer period of longevity over the adult female moths. The longevity of the adult female moth recorded a mean duration of 10.40 ± 2.33 days (1st generation), 11.40 ± 1.85 days (2nd generation), 11.20 ± 0.40 days (3rd generation), 11.20 ± 0.40 days (4th generation) and 13.40 ± 1.02 days (5th generation). The larval stages of wax moth are the damaging stage of the pest, in order to manage them, different integrated module incorporating cultural, biological and cold treatment was carried out. In determining the effectiveness of different integrated modules, all the treatments were found to be effective over the control. Combs kept in deep freezer at - 7°C recorded least damage of 1.53 per cent comb in the initial period however, with the elapsing of time Bt. var. kurstaki at 1 per cent in module III(b) proved to be better over the other modules. Pertaining to larval mortality, Bt. var. kurstaki at 1 per cent showed highest mortality as compared to the other modules and exhibited mortality per cent up to 36.66 per cent. In the context of reducing adult emergence as a measure of managing wax moth, the least per cent adult emergence of 33.33 per cent was recorded in module III where Bt. var. kurstaki @1 per cent was incorporated. All the modules comparatively showed satisfactory performance in managing the wax moth over the control in which no external intervention was employed. For best preventive measures all the modules can be suggested, with emphasis on regular and timely monitoring. For an effective and desirable management, module III with Bt. var. kurstaki at 1 per cent would be recommended against the pest. G. mellonella larva has been reportedly known to degrade polyethylene (PE), as such it has been assumed that certain microbes residing in the gut may be responsible. The investigation of the gut led to the isolation of 14 microbial isolates. The morphological characteristics of the fourteen isolates were mostly circular in shape, and had an entire margin, the colony color was chiefly white with raised elevation and exhibited smooth surface. Utilising 16S rRNA sequencing and analysing them on BLAST, the isolates were identified: it constituted of thirteen numbers of bacteria and one microalgae. The bacterial species ascertained were shown to be 2 strains of Acinetobacter radioresistens, 2 strains of Bacillus circulans, 2 strains of Enterococcus faecalis, Agrobacterium sp., Exiguobacterium aestuarii, Microbacterium zeae, Microbacterium paraoxydans, Sphingomonas pseudosanguinis, Sphingobium yanoikuyae, and one number of uncultured bacterium. The lone algae out of the 14 (fourteen) microbes isolated was confirmed as Picochlorum oklahomensis. A number of the above species has been reportedly known to degrade aromatic hydrocarbon, low density polyethylene, high density polyethylene, polystyrene etc. The precise mechanism of this microbes in degrading PE, function of the host i.e. G. mellonella larva and the microbes in degrading the plastic whether individually or together, merits further investigation. The process of PE degradation could be used to devise a biotechnological solution on an industrial scale for managing polyethylene waste.EnglishThesis