A study on the comparative predatory efficiency and development of Micraspis discolor (F.) and Menochilus sexmaculatus (F.) on tea aphid Toxoptera aurantii (Boyer de Fons.)

摘要

The tea aphid Toxoptera aurantii Boyer (Sternorrhyncha: Aphididae) is a major pest of the tea plant (Camellia sinensis (L.)). Micraspis discolor (F.) and Menochilus sexmaculatus (F.) (Coleoptera: Coccinellidae) are the most common predators of these pests in tea plantations of North East India. A laboratory study was conducted to evaluate the suitability of the tea aphid Toxoptera aurantii, as prey for these two ladybird beetles. The life cycle of M. sexmaculatus was found to be shorter than that of M. discolor. Aphid consumption by M. sexmaculatus was significantly higher than that by M. discolor. Aphid consumption by larvae of M. discolor and M. sexmaculatus was noticed to be higher in later instars. Females of both ladybird species consumed a significantly greater number of aphids per day than males. As for biological parameters and the predatory potential of the two ladybird species, the study results proved that M. discolor and M. sexmaculatus are effective biocontrol agents of the tea aphid and can be used in integrated pest management programs successfully