Biological parameters and feeding efficiency of Chrysoperla Carneastephens (Neuroptera: Chrysopidae) feed on Citrus mealy bug Planococcus Citri (Risso) (Hemiptera: Pseudococcidae) under controlled conditions

Abstract

Experiment was conducted to check the biological parameters and feeding efficiency of Chrysoperla carnea fed on Planococcus citrimealy bugunder controlled environment (24±1 °C with 60 ± 5 % RH), during 2018. Results regarding developmental time indicated that egg incubation, larva and pupal periods were 3.60±0.1, 9.65±0.19 and 6.01±0.17 days respectively. Apparent mortality (100qx) was maximum (11.11) for pupa and minimum (5.00) was during 3 rd instar. Life expectancy (ex) for egg phase was highest (5.69) and lowest for pupal phase (1.88).Killing power (K-value) was found minimum (0.02) for 1 st and 3 rd instar while maximum (0.2) was recorded for adult stage. Feeding on artificial diet consisted of honey + sugar + Yeast + honey, the pre-oviposition, oviposition and post oviposition periods recorded for C. carnea were 8.2±0.41, 31.4±0.50 and 5±0.30 days, respectively. First and last mortality were observed at the age of 13 and 45 days while fast step down decrease was observed after 27 days when fed on the same food. Total number of eggs laid per female were 341.2±6.90 eggs. Main feeding efficiency and efficiency per day feeding on two different host stages were also found for C. carnea. The maximum (233.85±4.43 and 75.25±3.13) crawlers and adult were consumed by larva stage while minimum (27.10±1.35 and 8.70±0.48) crawlers and adult were consumed by 1 st instar. The consumption day -1 were highest (37.06± 0.28 and 9.67± 0.68) for 3 rd instar while the 1 st instar consumed lowest 9.67±0.56 and 2.89±0.21 crawlers and adult respectively.