A compendium of insect pests and natural enemies associated with soyabean (Glycine max (l.) Merrill in Calabar, a humid area

Abstract

Field studies were carried out in 1992 and 1993 late cropping seasons to identify the species of insects and their effect on soyabeans in Calabar, a humid tropical environment. Two treatments were used, (that is sprayed and un- sprayed). Nuvacron (Monocrotophos), a systemic insecticide was applied at the rate of 400g a.i/ha using a CP3 knapsack sprayer. Spraying started six weeks (42 days) after planting and continued at three weekly intervals until three weeks to harvest. A total of three sprays were applied. Insect population was sampled using the direct observation and ground cloth methods. A total of thirty-seven insect species were recorded. Thirty-two of these insects were pests while five were predators. The most abundant insect pests were Coptosoma spp. belonging to the order Hemiptera, Family: Plataspidae. Others were Coleoptera (example, Lagria villosa; Chrysolagria cynicolis; Podagrica spp.; Chnootriba similis (=Epilachna similis Muls); Medythia quarterna; Chaetonecma pulla chapius) Pentatomid bugs such as Aspavia armigera (F), Nezara viridula (L) and Acrosternum acuta (Ray), Coreid bugs-Clavigralla spp. Riptorus dentipes, Alydidae, Cletus notatus, Mirperus spp and Paederus sabeaus); Orthoptera- e.g. Gymnogrillus lucens (Walker) Gryllidae). Others were unidentified lepidopterous caterpillars. Five predators were also recorded. These were Cheilomenes sulphurea (Coleoptera: Coccinellidae), Rhincoris bicolor (Hemiptera: Reduviidae), Black ants (unidentified), Sphrodomantis spp. and a number of unidentified spiders (Arachnidae).

Journal of Applied Chemistry and Agricultural Research Vol. 4 1997: pp. 33-36