Comparative Biology of Ladybird Beetle, M. Sexmaculatus Fab. on Different Aphid Species

Abstract

Freshly laid eggs of M. sexmaculatus were cigar shaped, yellow in colour with smooth chorion without any reticulation. The average incubation period was varied from 3.08 to 3.60 days on different aphid species. Freshly emerged grub was dark grey in colour with shining dark head capsule and legs. The duration of first instar was maximum on L. erysimi (2.68 days), while duration of second instar was maximum recorded on L. erysimi and A. nerri i.e. 2.88 days. Minimum duration of first and second instar grub was observed on A. nerri (1.96 days) and on A. gossypii (2.32 days), respectively. The maximum duration of third and fourth instar grub was found on L. erysimi (3.00 days) and H. coriandari (3.20 days), respectively. The significantly lowest total larval duration was found on T. maculata (10.24 days) and was at par with A. craccivora (10.88 days), A. gossypii (10.56 days), A. nerri (10.36 days) and B. brassicae (10.36 days). Maximum pupal period was recorded on A. craccivora (5.16 days) and minimum on B. brassicae (4.08 days). The average egg laying capacity of single female was 311.10 to 346.50 eggs, when reared on different aphid species. Longevity of male beetle was found maximum on A. gossypii (16.60 days), while female beetle lived longer on A. nerri (22.10 days). A. nerri had highest growth index (2.71) followed by A. craccivora (2.68). Thus, A. nerri proved to be the most suitable host for the development of M. sexmaculatus followed by A. craccivora, A. gossypii, H. coriandari, L. erysimi, T. maculata and B. brassicae. The mean entire life span was 28.2 to 31.8 days for male and 35.2 to 39.8 days for female on different aphid species.
DOI: 10.17762/ijritcc2321-8169.150712