Biology of spotted ladybird beetle, Harmonia octomaculata (Fabricius) (Coccinellidae: Coleoptera) on Lucerne aphid, Acyrthosiphon pisum (Harris) (Aphididae: Hemiptera) under laboratory conditions

Abstract

Ladybird beetles are important biological control agents for soft bodied insect pests viz., aphids, mealybug, scales etc. Augmentation and use of biocontrol agents are important strategies of IPM for any crop. An investigation on the biology of spotted ladybird beetle, Harmonia octomaculata (Fabricius) on Lucerne aphid, Acyrthosiphon pisum (Harris) was conducted under laboratory conditions. The results revealed that mean incubation period was 3.44 ± 0.50 days. The average hatching percentage was 94.37 ± 2.00 per cent. The first, second, third and fourth instar larva lasted for about 1.38 ± 0.49, 1.86 ± 0.35, 2.60 ± 0.49 and 3.58 ± 0.50 days, respectively. The total larval duration was 9.42 ± 0.95 days. The average pre-pupal and pupal duration were 1.1 ± 0.3 and 4.14 ± 0.57 days, respectively. The adult emergence of H. octomaculata was 92.17 ± 2.91 per cent. The sex ratio (Male: Female) was 1:1.39. The pre-oviposition, oviposition and post-oviposition period of H. octomaculata was 8.28 ± 1.11, 19.42 ± 1.44 and 7.80 ± 0.93 days, respectively. The fecundity was 396.16 ± 54.57 eggs during her ovipositional period. The male and female adult lived for 28.02 ± 1.48 and 35.50 ± 1.71 days, respectively while average total lifespan of male and female were recorded as 46.14 ± 1.69 and 53.64 ± 1.97 days, respectively.