Biology and morphometry of molsari leaf webber, Nephopteryx eugraphella ragonot (Lepidoptera: Pyralidae) on Molsari

Molsari (Mimusops elengi Linn.) is a large-sized ornamental tree attacked by many insect-pests with leaf webber-Nephopteryx eugraphella Ragonot being the key pest. Biology of N. eugraphella was studied on Molsari leaves at PAU, Ludhiana. In all five generations per year were observed and incubation period increased from 3.17 to 4.54 days, while the percent egg hatchability decreased from 90.83 to 72.99 per cent in successive generations. Mean larval period varied from 15.28 days in June to 19.41 days in December. The size of the larvae varied from 1.18-1.41 × 0.26-0.45 mm in I instar to 19.24-21.88 × 0.99-1.78 mm in full grown larva. Pre-pupal and pupal period ranged between 0.50 2.34 days and 5.89-9.62 days with pupal survival being the highest i.e. 92.79 % in the months of August and September. Adult female and male were 9.50-11.25 mm and 9.00-11.21 mm long and lived for 5.31 to 9.79 and 3.32 to 6.75 days respectively. Gravid female laid 42 to 101.80 eggs and the sex ratio (male: female) ranged between 1:1.13 to 1:1.40. The total life cycle of the insect ranged between 32-45 days. Pest was found to be more active during July, August and September.