Diversity and distribution of lepidopteran floral visitors in different land-use types in Mabira Central Forest Reserve, Uganda

Abstract

Globally, the population of insect pollinator species is in decline at local and landscape levels due to land-use intensification occurring in different land-use types. Insect pollinators in Uganda are not well researched despite the use of pollinator unfriendly farm management practices. Majority of food and cash crops grown in this country depend on insects for improved yield and quality of fruits and seeds. Mabira Central Forest Reserve and the surrounding agricultural areas were sampled for Lepidoptera known to play critical roles in pollination services to plants. The species richness, number of individuals of each species, and factors that affect their diversity across forest-agricultural landscape were determined. Sweep nets and light traps were used to sample butterflies and hawkmoths respectively across forest-agricultural landscapes. Result show significant decline in Lepidoptera species richness and relative abundance from forest to agricultural landscapes. Similarly, species richness and relative abundance of forest-dependent species (specialist) declined across forest to agricultural landscape. Presences of different plant forms and vegetation cover types had significant effects on species richness and abundance. The observed trends in species richness and distribution among different ecotypes across the different land uses highlights the need to protect forests habitats neighbouring or within agricultural areas for increased pollination services that improves crop yields and quality