Vol. 11, Special Issue 7 (2022)

Author(s):
Aravinthraju K, Moorthy AV and Roopika M

Abstract:
Spodoptera litura (Fab.) is a polyphagous pest which gained its importance by affecting different agricultural and horticultural crops, causing severe damage and economic losses. It has wide range of hosts including pulses, oil seeds, fiber crops, vegetable crops, fruit crops etc. Likewise this pest feeding on cassava was noticed in Madurai district, Tamilnadu and hence a study on biology of S. litura with cassava as its host was carried out in Agricultural college and Research Institute, Vazhavachanur. Observation on egg, larval, pre pupal and pupal periods along with adult longevity was done, by which total life cycle was calculated. S. litura has four stages in its life cycle viz., egg, larvae, pupa and adult stages, hence it undergo complete metamorphosis. The mean egg period was found to be 2.0 ± 0.71 days, with 20.6 ± 2.07 days of mean larval period (six instars), 2.4 ± 0.55 days of mean pre pupal period, 10.2 ± 1.10 days of pupal period and 4.8 ± 0.84 days of mean adult longevity. Hence the total life cycle was found to be 40 ± 2.83 days. Comparatively the larval and pupal period of S. litura feeding on cassava was high, but the adult longevity and fecundity rate was very low and so cassava was not found to be potential main host for S. litura.