Effect of Prey Availability on Development and Reproduction of the Predatory Lacewing Dichochrysa prasina (Neuroptera: Chrysopidae)

Preimaginal development and reproduction of the predatory lacewing Dichochrysa prasina Burmeister (Neuroptera: Chrysopidae) when its larvae had access at different nymphal numbers of the aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) were studied under laboratory conditions at 25 ± 1°C and a photoperiod of 16:8 (L:D) h. Preimaginal development decreased from 46.0 to 31.6 d for females and from 41.4 to 31.5 d for males, with an increase in the number of available aphids from five to 110 nymphs of M. persicae per larva of D. prasina. Preimaginal survival ranged from 55.8% at the lowest to 86.0% at the highest aphid numbers. Prey consumption by D. prasina larvae increased with an increase in aphid numbers, with the third instar being the most voracious. Longevity of D. prasina females ranged from 38.2 to 54.5 d, and total egg production ranged from 59.2 to 369.7 eggs per female at the lowest and highest prey numbers tested, respectively. The estimated values for the intrinsic rate of increase (rm) were affected by prey availability and the highest rm (0.0838) was recorded at the highest prey number tested. Based on the results of the current study, it is likely that D. prasina can develop and reproduce either at high or low density aphid populations in the field, and effectively suppress them.