Insect diversity on Calotropis gigantea (L.) in Sri Lanka

Abstract

Calotropis gigantea is a drought-resistant and salt-tolerant medicinal plant native to Sri Lanka. Although C. gigantea is widely distributed in Sri Lanka, information on insects associated with the plant is less understood. The objective of the study is to identify the diversity of insect fauna associated with C. gigantea. Surveys were conducted in 120 sites covering all provinces of Sri Lanka to document the insect fauna associated with C. gigantea and their biotic associations. The insects found in C. gigantea were cataloged as pests, pollinators, and occasional visitors. A total of thirteen morphospecies of phytophagous pests, six species of pollinators, and fourteen species of occasional visitors were documented. Dacus persicus and Paramecops farinosa were the highly damaging pests while Sphaeroderma sp. was more widespread. Xylocopa spp. were the most abundant insect pollinators. Dacus persicus and P. farinosa were identified as monophagous species of C. gigantea. Occasional visitors belonged to five orders and their diversity was very high. As the initial record from Sri Lanka, the findings of the study provide information on the identification of the insect fauna associated with Calotropis and their association with C. gigantea.