Sangha, K. S.Gurveer Singh2023-12-112023-12-112023Gurveer Singh (2023). Biology and management of molsari leaf webber, Nephopteryx eugraphella Ragonot (Lepidoptera : Pyralidae) (Unpublished M.Sc. thesis). Punjab Agricultural University, Ludhiana, Punjab, India.https://krishikosh.egranth.ac.in/handle/1/5810202579Molsari (Mimusops elengi Linn.) is a large-sized ornamental tree with several medicinal properties. It is attacked by a number of insect-pests, the most important being the leaf webber- Nephopteryx eugraphella Ragonot. The larvae of N. eugraphella feed on leaves, apical shoots and flower buds, thereby giving a burnt appearance to the tree. In the present study, research on biology and management of molsari leaf webber, were carried out at Forest protection laboratory and forestry research area, Department of Forestry and Natural Resources, Punjab Agricultural University, Ludhiana, during 2021-2022. Biology was studied on molsari leaves with five generations (Generation I - Generation V) with a life span ranging between 32 to 45 days. Biological studies revealed that incubation period increased from 3.17 to 4.54 days, while the percent egg hatchability decreased from 90.83 to 72.99 per cent with increase in generation number. The mean duration of I, II, III and IV larval instars ranged between 2.96 to 3.92, 4.08 to 5.12, 3.56 to 4.96 and 4.69 to 5.40 days respectively during the different generations. The prepupal and pupal weight ranged between 47.20 to 55 mg and 45.20 to 60.60 mg. The length of I, II, III, IV, full grown larval instars; pre-pupa; pupa; adult female and adult male varied between 1.22 to 1.31, 4.18 to 4.48, 13.22 to 13.36, 19.22 to 19.88,19.40 to 21.61; 12.41 to 13.44; 9.72 to 10.88; 10.05 to 10.57 and 9.62 to10.32 mm respectively, whereas, breadth varied between 0.31 to 0.38, 0.46 to 0.67, 0.66 to 0.76, 0.66 to 1.11, 1.19 to1.51; 2.81 to 3.14; 2.97 to 3.23; 19.92 to 20.74 and 19.03 to 19.73 mm respectively. Duration of larval period, pre-pupa, pupa, adult female and adult male varied from 15.28 to 19.41, 0.60 to 2.11, 6.52 to 9.24, 6.00 to 9.38 and 3.86 to 6.33 days respectively. Interestingly, per cent survival of larva and pupa decreased in the successive generations. Additionally, sex ratio (male : female) ranged from 1:1.13 to 1:1.40. It was found that pre-mating, mating, pre-oviposition, oviposition and post-oviposition periods varied from 1.22 to 1.93, 0.42 to 0.62, 1.64 to 2.55, 2.28 to 3.62 and 2.08 to 3.21 days respectively. The larvae of N. eugraphella feed on leaves, apical shoots and flower buds, thereby giving a burnt appearance to the tree. Peak activity of the insect was recorded in the months of July, August and September with Tmax, RHm, RHe and rainfall showing significant positive correlation with insect infestation. Apis dorsata, Apis florea, Ischiodon scutellaris, Vespa orientalis were recorded as the casual visitors of molsari while among parasitiods Cotesia flavipes, Compislura sp, Eurytoma sp and Xanthopimpla sp were observed. Among predators, five Spiders (Marpissa mandala, Xysticus sp, Phidippus punjabensis, Rhene indicus and Sparassus sp) and one beetle (Parena nigrolineata) were recorded. Spinosad 48% SC (0.9 ml/l) proved to be the best treatment in suppressing the webs and larval population followed by Bacillus thuringiensis @ 4 g/l and Beauve ria bassiana @ 12 g/l.EnglishThesis