Department of Agricultural Entomology, Bidhan Chandra Kirshi Viswavidyalaya, P.O. Krishi Viswavidyalaya, Mohanpur-741252, West Bengal, (India).
*Address for correspondence: c/o. Shri Anindya Chakrabarty, North Nimta, Paikpara, Amrakanan, P.O. Nimta, Calculta-700049, West Bengal, (India)
1Present place of work: Bidhan Chandra Krishi Viswavidyalaya, Regional Research Station, Old Alluvial Zone, Majihan, Patiram-733133, Dakshin Dinajpur, West Bengal, (India).
The cumulative effects of some ecological factors (temperature, food and population density) on the development biology of Dysdercus koenigii Fab. were studied at 80% R.H. for three successive generations. Combined stress due to crowding, temperature and food produced clear symptoms in the form of reduced fecundity, fertility, life span, survival rate, body length and increased egg length, and fluttering. Differential combinations of temperature (36, 25 or 16°C), food (0.2 or 4 seeds/individual) and population density (10 or 100 pairs/cage) recorded 108.20–150.67 eggs/female. 72.12–89.26% fertility (hatchability), life span of 23.12–30.14 days for male, and 21.42–27.49 days for female. The mortality ranged from 4.11–25.32% for nymphs and 0–35.35% for adults. The body length (including rostrum) varied from 30.01 to 32.74 mm in male and 33.27–35.12 mm in female, and the egg length being 1150.62–1268.32 μ. Metathetely lind prothetely were observed under extremes of temperature aud crowding.
