Variations in abundance of Imbrasia epimethea (Lepidoptera: Saturniidea) on Petersianthus macrocarpus in different forest types in Central Cameroon

Abstract

Edible caterpillars are of vital importance to rural communities in developing countries providing high protein values and income. However, their ecology particularly seasonal fluctuations in their numbers is still poorly understood. With the ongoing climate change and increasing deforestation, their survival is a crucial issue. The aim of this study was to assess the structural characteristics of Petersianthus macrocarpus (Lecythidaceae) on the abundance of edible caterpillars of Imbrasia epimethea (Saturniidea). The forest area on the outskirts of Yaoundé is an important production basin for edible caterpillars making a perfect medium to answer questions on the variations in the abundance of caterpillars of I. epimethea in relation to the forest type of P. macrocarpus. Concerning biometric parameters, the [20-30[ cm diameter class in agroforest had more edible caterpillars (31.1 %). In the secondary forest and swamp forest, it was the [50-60[ cm diameter class with respectively 34 % and 27.4 %. In terms of height, the [30-40[ m height class contained more edible caterpillars (68.50 %), whereas the [60-70[ m height class represented the stratum with the least edible caterpillars (5.10 %). In different forest types, the abundance of caterpillars of I. epimethea according to the social status of P. macrocarpus individuals showed that caterpillars are found in abundance preferentially on dominant individuals (52.7 % in swamp forest, 49.7 % in secondary forest and 45.6 % in agroforest). The mean abundance of I. epimethea caterpillars was higher in secondary forest (563 ± 62 caterpillars) compared to agroforest and swamp forest. In contrast, swamp forest had the lowest mean abundance of edible caterpillars (375 ± 24 caterpillars) according to the social status of P. macrocarpus. These results point way to a better understanding of the use and management of an economically important NTFP.