Diversity and Abundance of Butterfly Species and Farmers’ Pesticide Use Practices and Perceptions on Insect Pollinators in Farmland and Ngangao Forest, Taita Hills, Kenya

Abstract

Ngangao Forest is one of the relics of the Taita Hills ecosystem that forms the northernmost Eastern Arc Mountains (EAM). The mountains are globally regarded as biodiversity hotspots with a degree of endemism in both flora and fauna. Continuous anthropogenic disturbances threaten the rich biodiversity in Taita Hills. Farmers in Taita Hills use chemical pesticide to manage pests and diseases often at the expense of biodiversity and the environment. This study aimed at assessing the diversity of butterflies at the edge of Ngangao Forest and adjacent farmlands, and to document farmers’ pesticide use practices and their perception on insect pollinators for conservation. Data on diversity and abundance of butterflies was collected for six months from December 2017 to May 2018 using line transect walks and butterfly-baited-traps. A survey on farmer pesticide use practices and perception on pollinators was conducted in small scale farms surrounding Ngangao Forest in March and April 2018. Seventy farmers were sampled randomly within ten farming villages and a structured questionnaire was administered. A total of 17,438 specimens of butterflies were collected belonging to five families, 62 genera and 144 species. There was a significant difference in the number of butterfly species and their abundance along the forest edge compared to the farmlands. Mean species richness and abundance of butterflies among months sampled was also significantly different (p<0.05). The most abundant species in both habitats were Belenois margaritacea kenyensis 7.6%, Eurema brigitta brigitta 6.3%, Zizula hylax 5.9%, Mylothis sagala 5.4% and Papilio nireus lyaeus 5.2%. Three butterfly species that are endemic to Taita Hills, namely; Cymothoe teita, Papilio desmondi teita and Charaxes xiphares desmondi, were detected in the study area. These findings show that Ngangao forest edge harbors a higher diversity of butterfly species and endemism compared to the farmlands. Measures should be put in place to protect the