Biology ofCryptolaemus montrouzieriMulsant on mealy bugs and aphids

Abstract

A study on biology of Cryptolaemus montrouzieri on mealy bugs and aphids indicated that the incubation period of C. montrouzieri was observed to be significantly minimum to the extent of 4.59 days on P. solenopsis followed by 4.94 days (M. hirsutus) and 5.29 days (A. gossypii). The significantly maximum egg hatching of C. montrouzieri (91.40 per cent) was observed on M. hirsutus followed by P. solenopsis (85.80 per cent) and A. gossypii (79.20 per cent). The significantly shortest larval duration (22.99 days) and highest growth index (3.88) were observed in the case of those larvae of C. montrouzieri which were grown on P. solenopsis followed by M. hirsutus (25.02 days and 3.46). the larval development of C.montrouzieri was completed by passing through four instars on mealy bugs and aphids under investigation. the mean larval instar duration of C. montrouzieri was observed to be minimum to the extent of 4.60 days on P. solenopsis followed by M. hirsustus (5.00 days) and A. gossypii (5.66 days). The significantly lowest pupal duration to the extent of 7.97 days was observed when grown on P. solenopsis followed by 9.95 days on M. hirsutus and 11.66 days on A. gossypii. Significantly the highest adult emergence of C. montrouzieri to the tune of 84.84 per cent was observed in the case of those larvae which were reared on P. solenopsis followed by M. hirsutus (80.38 per cent) and A. gossypii (72.11 per cent). The significantly lowest developmental period of C. montrouzieri to the extent of 38.29 days was recorded on P. solenopsis. The significantly highest longevity of male and female beetles of C. montrouzieri was recorded on P. solenopsis and M. hirsutus, respectively. Significantly the shortest life-cycle duration to the extent of 102.39 and 110.19 days by male and female beetles of C. montrouzieri was observed on A. gossypii. The significantly lowest pre-oviposition period of C.montrouzieri to the tune of 7.56 days was recorded on M. hirsutus followed by P. solenopsis (7.70 days). The significantly highest oviposition period (42.06) of C. montrouzieri was observed when fed on P.solenopsis followed by M. hirsutus (34.24 days). the female beetle of C.montrouzieri laid significantly highest eggs (205.2) when its immature stage fed on M. hirsutus followed by P. solenopsis (96.33). while its egg laying was significantly lowest (51.80) on A. gossypii.