Life Cycle of the Ladybird Beetle. Cheilotnenes lunata Fab. (Coleotera: Coccincllidae), A Potential Biocontrol Agent of the Cowpea Aphid, Aphis croccivora (Koch.) (Homoptera: Aphididae)

Abstract

The life cycle of the ladybird beetle, Cheilomenes lunata Fab.(Coleoptera: Coccinelidae) on Aphis craccivora Koch was studied under fluctuating laboratory condition of 25 – 32°C and 33 – 73° RH. The average incubation period was 3.2 days with a hatchability of 93.1 %. There were four larval instal’s with developmental duration averaging 3.0, 2.2, 2.2 and 4.2 days for the 1st, 2nd , 3rd and 4th larval instars, respectively. The total larval developmental period ranged from 9.7 – 13.5 days and the pupal period lasted for 4.8 days. Mortality at these stages were 37.6 and 7.5% respectively. Pre-oviposition period averaged 3.7 days. The mean number of eggs per female was 1257.4 and the mean oviposition period was 47.0 days. The longevity of mated males and females averaged 87.9 and 72.1 days, respectively, while those of unmated males and females averaged 80.8 and 61.5 days, respectively. The male to female ratio was 1: 1. Information were given on the moulting process and copulation of the ladybird beetle.