Spatial distribution of cocoon nests and egg clusters of the silkmoth Anaphe panda (Lepidoptera: Thaumetopoeidae) and its host plant Bridelia micrantha (Euphorbiaceae) in the Kakamega Forest of western Kenya

Abstract

A study on the spatial distribution of the silkmoth Anaphe panda (Boisduval) cocoon nests, egg clusters and the host plant Bridelia micrantha (Hochst) Baill. was conducted in two different habitats of the Kakamega Forest of western Kenya: Ikuywa (indigenous forest) and Isecheno (mixed indigenous forest). The mean densities of cocoon nests, egg clusters and B. micrantha were significantly different in the two blocks and were not semi-randomly distributed in the two habitats. The host plants were underdispersed in the indigenous forest, whereas they were overdispersed in the mixed indigenous forest. The cocoon nests were overdispersed and the silkmoth egg clusters were underdispersed in the two blocks of forest. This study reveals that A. panda tends to distribute its egg clusters uniformly over the lower and middle crown of B. micrantha with a preference to eastern localization and confirms the insufficient presence of populations of this silkmoth in a mixed indigenous forest compared with an indigenous forest. Consequently, indigenous forests should be managed in a sustainable way and more indigenous tree species should be used in reforestation campaigns.