Temperature dependent developmental biology and survival of Spodoptera litura life stages on soybean

Abstract

The effect of temperature on development of different life stages of Spodoptera litura (Fabricius) on soybean
(Glycine max L.) was assessed under laboratory conditions in environmental growth chambers at six constant temperatures viz., 15, 20, 25, 30, 35 and 36 ± 1 °C. Temperature had a pronounced effect on S. litura reared on soybean. Development was linear for immature life stages in the temperature range of 20 and 35°C. Developmental durations of different life stages decreased with increase in temperature till 35 °C. The decrease in duration for egg stage was from 10.7 to 1.9 days, for larva from 28.0 to 10.8 days, for pupa from 16.0 to 5.9 days and total immature development (egg to adult emergence) was from 49.0 to 18.7 days. At 36 °C, development durations increased for all life stages indicating non-linear relationship at higher temperatures. Completion of life cycle was affected at lower extreme temperature (15°C). Highest probability of survival was observed at 20 °C from Kaplan-Meier survival analysis. Oviposition period, fecundity and longevity were also influenced by temperature with peak fecundity at 25°C.