Full body sensillar diversity of pumpkin fruit fly, Bactrocera tau (Walker) (Diptera: Tephritidae)

Abstract

The pumpkin fruit fly, Bactrocera tau (Walker) (Diptera: Tephritidae) is one of the most serious insect pests of fruits, vegetables and nuts over the world due to its polyphagous nature and high reproductive rate. To gain insight into their sensory system, the external morphology, typology, density, and distribution of sensilla on full bodies of both adult male and female B. tau were observed using a scanning electron microscope. The observed sensilla showed organ as well as sex specific differences. Seven previously described sensilla (two non-olfactory, five olfactory with 17 subtypes) and a new sensillum named as “branched sensilla” (two subtypes) were identified and observed on the different body parts. Olfactory sensilla named as sensilla trichodea and sensilla basiconica were reported on the compound eyes for the first time. Majority of the olfactory sensilla were reported on the head appendages. The presence of species-specific as well as sex-specific branched sensilla in females showed different typology patterns of sensilla. The potential roles of observed sensilla were hypothesized through comparative analysis with prior research. The current findings can provide a reference for understanding the diversity of various olfactory and non-olfactory sensilla in B. tau as well as sex-specific morphological differences and functions of various body parts; thereby, aiding in the development of precise methods for regulating and managing insect behaviour.