Antennal sensilla of phytophagous and predatory pentatomids (Hemiptera: Pentatomidae): a comparative study of four genera

Abstract

Antennal sensilla of four genera of Pentatomidae (Hemiptera: Heteroptera) belonging to two subfamilies viz., Pentatominae and Asopinae were examined using scanning electron microscopy. The representatives selected from the subfamily Pentatominae (phytophagous)—Dolycoris indicus (Stål) and Plautia crossota (Dallas), and from the subfamily Asopinae (predatory)—Perillus bioculatus (Fabricius) and Eocanthecona furcellata (Wolff). They were studied in order to morphologically differentiate the sensilla present on the antennae. This study indicated the presence of six types of sensilla, most of which were found on the flagellar segments rather than on the scape or pedicel. Sensilla campaniformia were recorded on the flagellar segments as well as the scape and pedicel. Phytophagous species (D. indicus and P. crossota) showed a higher number of sensilla trichodea, basiconica and chaetica whereas sensilla coeloconica were restricted to the predatory species studied (E. furcellata and P. bioculatus). These differences may be related to their evolutionary history. The presence of multiporous chemo-sensilla as basiconic sensilla type and sensilla placoidea reflect the ability of the antennae to perceive chemical stimuli. A relatively higher abundance of mechanoreceptors could be considered as potential detectors for various mechanical functions and these appeared to be correlated with the genus and type of feeding but not with the sex of the studied species.