Sandhu, Inderpal SinghCheema, Rupinder Singh2018-12-022018-12-022018http://krishikosh.egranth.ac.in/handle/1/5810085030The studies on influence of different temperature and carbon dioxide levels on biology, food consumption and nutrional indices of Plutella xylostella Linnaeus on cauliflower were conducted by collecting insect population from two locations viz. Ludhiana and Malerkotla. Study was conducted at six different combinations of temperature and CO2 levels viz. 25:11ºC and 28:14ºC at 350, 400, 450 ppm carbon dioxide concentrations. The incubation period of eggs decreased non-significantly with increase in temperature and CO2 levels in population of both the locations. In Ludhiana population total larval duration, pupal duration, female adult longevity, male adult longevity decreased from 11.68, 4.32, 14.17, 20.51, respectively at 25:11ºC to 10.02, 3.71, 11.14, 16.62 days respectively, at 28:14ºC. Similarly when CO2 levels increased from 350 ppm to 450 ppm total larval duration, pupal duration, female adult longevity, male adult longevity decreased from 11.43, 4.22, 13.85, 20.17, respectively to 10.30, 3.77, 11.37, 16.90, respectively. Whereas fecundity P. xylostella increased significantly from 165.56 to 186.00 eggs female-1 with increase in temperature and from 167.50 to 183.67 with increase in CO2 levels which indicate reduced generation time ultimately more number of generations per year. Similar results were found in Malerkotla population. Likewise food consumption, consumption index, relative growth rate, approximate digestibility, efficiency of conversion of ingested food of third instar larvae of Ludhiana population increased significantly from 5.36, 0.92, 0.47, 50.96, 45.83 to 5.59, 1.20, 0.53, 55.29, 50.71, respectively with increase in CO2 levels from 350 ppm to 450 ppm. Similarly in fourth instar larvae of both the populations, value of food consumption, CI, RGR, AD and ECI increased significantly with the increase in temperature and CO2 levels. Thus it can be concluded that elevated temperature and carbon dioxide and their interactive effect influences the different biological and nutritional indices of P. xylostella.ennullThesis