Growth and development of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) on cultivated and indigenous graminaceous host plants
Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) is an economical y importent pes of graminaceous crops such as maize, sorghum and pearl millet. Although C. partellus infestations are common in graminaceous crops, this species prefers to lay eggs on certain indigenous grasses. Indigenous graminaceous hosts that are preferred for oviposition bu that result in poor larval survival have been used as trap crops in habitat management systems for this pest. In this study the growth and development of C. partellus on different host plants was investigated. These hosts were maize (Lea mays), sorghum (Sorghum bicolor), sweet sorghum (Sorghum bicolor), pearl millet (Pennisetum glaucum) and the grasses, P. purpureum (Napier grass) and Hyparrhenia tamba (blue thatching grass). Head capsule width larval and pupal numbers and weight and development period for larvae and pupae were recorded. While larval survival on crops was high, no larvae pupated on indigenous grasses. Eclosion was observed from the pupae collected from maize, sorghum, sweet sorghum and pearl millet but not from the grasses. This study determined that the indigenous gasses, H. tamba and P. purpureum are poor hosts for C. partellus compared to the cultivated crops and that they therefore have characteristics that qualify them as potential trap crops for this pest.