Population, Host Preference and Feeding Potential of Chrysoperla Carnea (Stephens) on Different Insect Hosts in Cotton and Mustard Crops

Abstract

Studies on the population, host preference and feeding potential of Chrysoperla carnea (Stephens) on different insect hosts were conducted in field and laboratory conditions in the year 2011. The results revealed that the maximum numbers of Bemisia tabaci 19.84 (±2.46), Aphis gossypii 23.14 (±0.84), Amrasca devastan 13.42 (±2.10) and mealybug 50.62 (±5.44) per leaf were found on cotton crop. Similarly, maximum population of B. tabaci, A. devastan, and eggs of Bagarada Picta was recorded as 9.44 (±1.14), 6.44 (±0.74), 38.13 (±1.44) and 22.144 (±7.83), respectively on mustard crop. More activities of C. carnea (0.32±0.10) per plant were recorded on mustard as compared to cotton (0.32±0.14). The population of C. canea was negatively correlated with B. tabaci population (-0.019 NS) and positively with A. devastan (0.145 NS), A. gossypii (0.700**) and mealybug (0.834**), respectively on cotton. Similarly, negative correlation with B. tabaci population (-0.193 NS) and positive correlations with A. devastan (0.202NS), L . erysimi (0.923**) and B. picta (0.925**), respectively were recorded on mustard crop. The 3rd instar larvae voraciously fed on 3rd instar nymphs of all sucking insects. They consumed 66.14 (±2.18) A. gossypii, 61.14 (±1.06) P. solinopsis, 32.78 (±1.32) B. tabaci and 19.66 (±1.34) A. devastans, respectively. The green lacewing fed 30.37 (±1.51) aphid day-1 , followed by mealy bug (12.30± 1.48), whiteflies (1.94± 0.30), and jassid (0.43±0.095). It is concluded from the results that C. carnea displayed its maximum activities when pest population were at their peaks. The third instar grubs were voracious on 3rd instars of all prey hosts. A. gossypii was the most preferred host in cotton and L. erysimi in mustard crop. B. tabaci had no impact on population activities of C. carnea.