An appraisal of select insect taxa in Sri Lanka

Abstract

The chapter provides information on diversity of selected insect taxa, namely, Isoptera, Aphididae, Thysanoptera, Formicidae, and Apidae, and of the rice fields in Sri Lanka. Isoptera of the island comprises 76 species in 29 genera and 4 families, with 33 species restricted to the island. Fauna is rich in wood-feeding foragers and fungus-growing wood feeders and poor in humus and soil feeders. Seventy-four species of aphids in 40 genera and 8 subfamilies have been documented with the exception of subfamily Anoeciinae. Host plant specificity is not so pronounced among aphids except for a few restricted to endemic plants and specific weeds. Thysanoptera are represented by 113 species in 63 genera. Among them are many cosmopolitan pests and several potential viral vector species with vegetables, ornamentals, and cut flowers harboring a large majority of thrips. Ants comprise 181 species in 61 genera and 12 subfamilies. Of special interest is the endemic SF Aneuretinae, solely represented by the relict ant, Aneuretus simony, now known to be widely distributed and abundant. Bees comprise 144 species of pollen bees and 4 species of honeybees in 38 genera and 4 families. Pollen bees are best known for their nesting habits as ground, hollow stem (leaf-cutter bees), and wood (carpenter bees) nesters. Among them are several specialist bees. Rice fields are rich in insects, due to their habitat heterogeneity, harbored 317 species, belonging to 19 orders and 104 families, during the two cultivation cycles, Yala and Maha.