Diversity and abundance of litter insects within some exotic tree species in the arboretum of Ruhande, Rwanda.

Abstract

Insects are the most diversified animals, equivalent to 55% of all identified and named species on earth and play great role in ecosystem functions. This has motivated to study insect diversity in the arboretum of Ruhande where they were not yet studies. Three tree plantation species were selected for the study including Pinus patula, Grevillea robusta, and Cedrela serrata . Litter insects were hand collected, and transported in the laboratory for identification. Results indicated the predominance of three orders, including Hymenoptera, Coleoptera, and Lepidoptera . Classification at family level obtained 29 families, and Formicidae family was the largest. Biodiversity analysis indicated that insects were the most diversified in the litter of Grevillea robusta followed by Cedrela serrata plantations. It is suggested that the abundance and diversity of insects were related to habitat conditions such as litter cover, shade, and soil chemical conditions. This study provides baseline information on litter insect population as affected by plantation species. Further studies are needed in order to investigate the most suitable tree plantation species for insect diversity conservation in Rwanda. Keywords : Insects; Insect abundance; Insect diversity.