Biological traits and predation efficiency of Menochilus sexmaculatus (F.) (Coleoptera: Coccinellidae) on different hosts

Abstract

Menochilus sexmaculatus (Fab.) (Coleoptera: Coccinellidae) is an important bio control agent against bean aphid, mustard aphid, wheat aphid. A detailed research work was carried out in the laboratory of the Department of Entomology, HSTU, Dinajpur to study the Consequence of hosts on the Biology and predation efficiency of Menochilus sexmaculatus (Fab.) (Coleoptera: Coccinellidae) on three aphid species such as bean aphid, mustard aphid and wheat aphid (Aphis craccivora, Lipaphis erysimi and Rhopalosiphum maidis). During November 2014 to April 2015.The average incubation period was varied from 3.80 to 3.95 days on three different aphid species. The duration of first instar was maximum on R. maidis (2.60 days), while duration of second instar was maximum recorded on L. erysimi i.e. 2.70 days. Minimum duration of first and second instar larvae was observed on Aphis craccivora (2.40 and 2.50 days) respectively. The maximum duration of third and fourth instar larvae was found on L. erysimi (3.20 and 2.60 days) respectively. Significantly lowest total larval duration was found on R. maidis (9.70 days) while the highest on L. erysimi (11.00 days). Maximum pupal period was recorded on R. meidis (3.20 days) and minimum on L. erysimi (3.00 days). The average egg laying capacity of single female was 286.00 to 365.00 eggs, when reared on different aphid species. Adult longevity of the beetle was found maximum on L. erysimi (42.60 days), and minimum on A. craccivora (34.60 days).The duration doubling times varied significantly among the aphid species. The mean generation time (T) among the varieties of aphids were 29.299, 28.704, 29.299 days, respectively. The longest duration was found in wheat and mustard aphids respectively and the shortest duration was in bean aphid .The gross reproductive rate (GRR) was highest (257.13) for the wheat aphid and lowest (202.88) for the bean aphid. The average predation efficiency of mustard aphid (1660.80), wheat aphid (1465.00) and bean aphid (1624.90) respectively.