Observations on the insect fauna of shaded and unshaded Amelonado cocoa

Abstract

AbstractThe insect fauna of a block of Amelonado cocoa trees at Tafo, Ghana, partly shaded by Gliricidia sepium and partly unshaded was sampled. Crematogaster clariventris (Mayr) and Oecopyhlla longinoda (Latr.) were the most numerous species of ants, the former occurring on 84% of the trees and the latter on 17%. There was a considerable overlap in the distribution of the two species. Thirty-two other species of ant were collected by pyrethrum knockdown sprays from the cocoa canopy, and 47 species were collected from leaf litter beneath the trees. More species of ant were recovered from litter on shaded plots than on unshaded ones. There was some avoidance of trees occupied by O. longinoda by certain canopy .ants. A greater number of Lepidoptera larvae, Orthoptera and the mirid Sahlbergella singularis Hagl were collected by pyrethrum knockdown sprays from unshaded plots than from shaded ones, whereas Diptera and Hymenoptera other than ants were more numerous on shaded plots. The most abundant coccid was Stictococcus sjostedti Ckll., a species tended for its honeydew by both dominant ants; it was more common on shaded plots. Mealybug species, of which Planococcoides njalensis (Laing) was the most common, were more abundant on unshaded plots.