Notes on Sugarcane Trash Caterpillars (noctuidae) and Effects of Defoliation on the Crop

At least 7 species of Noctuid moths have been reared from caterpillars collected beneath trash in cane fields, and some at least feed at night on leaves of young ratooning sugarcane, the chief offender being Mythimna phaea Hamps. Feeding appeared to be initiated by onset of darkness, but a reduction in numbers feeding occurred before dawn. Natural enemies included 6 Tachinid flies, an Ichneumonid wasp, a species of Entomophthora and what appeared to be a polyhedral virus. Insecticide trials showed that, despite the trash blanket's protective covering, a measure of control was achieved with the following insecticides:Endosulfan, DDT, carbaryl, Bacillus thuringiensis. The moths have been caught in light traps, which may have some practical application as indicators of forthcoming infestations Artificial defoliation could cause a reduction in yield of 18,6 tons cane per hectare, accompanied by reduction in size of internodes.