Effect of Population Density on Fecundity of Chrysoperla Carnea (Neuroptera: Chrysopidae) Under Laboratory Conditions.

Abstract

The reproductive potential of Chrysoperla Spp. has been examined by a number of researchers and reported that population density of insects in rearing cages play a major role for their mass production of adult green lacewings. Therefore, an experiment was conducted for efficient and quality production of the generalist predator, Chrysoperla carnea (Stephen) with respect to laboratory rearing programme. Different population densities i.e. (5, 10, 15 and 20) were paired in glass chimneys of 1750 cm3 to determine the effect of adult density of C. carnea on its biology. Studies revealed that five pairs (male and female) of adults produced maximum mean number of eggs (1797.0±76.05) while highest hatching (1452.8±44.55), pupae recovered (1196.8±49.10) and adult emergence (838.2±42.14). Whereas, minimum number of egg laying (814.25± 121.83), hatching (655.25±105.13), number of pupae (506.0± 97.23) and adult emergence (268.0±44.50) was recorded in treatment when 20 pairs were confined. The lower percentage of deformed adults (19.82±1.03) was recorded at 5 pairs density followed by 10 (28.0±0.91) and 15 (35.3±0.64) pairs. Maximum deformed adult percentage (42.25± 0.47) was observed in treatment where 20 pairs were confined. Therefore, findings of this study suggested that five pairs adult density of C. carnea in particular given space was the best among all treatments.