A study on antennal sensilla of the female worker castes of Tetragonula iridipennis (Smith) (Hymenoptera: Apidae)

Tetragonula iridipennis are a group of stingless bees which are effective pollinators of the tropics.  They are believed to be endowed with efficient chemo (olfactory and gustatory) and visual sensory systems.  Sensory perceptions in these insects are understood minimally, so the primary sensory organ – the antenna of the insects was probed to understand the sensilla diversity and distribution. Antennal sensilla profile of an insect often reflects the sensory repertoire of the insect. Light and scanning electron microscopic studies were carried to understand the antennal sensilla organization. Sensilla were typified by their morphological features. Sensilla basiconica, four subtypes of sensilla trichodea, sensilla trichodea curvata, sensilla placodea (pore plates) were the major types of antennal sensilla we could identify from Tetragonula iridipennis. The hygroreceptive sensilla ampullacea and CO₂ receptive sensilla ampullacea were conspicuously absent on the antenna of Tetragonula  iridipennis suggesting differences in the sensory ecology of this bees.