Fine structure of sensory apparatus on the head of Cixiopsis punctatus.

The external morphology of the heads of adult male and female Cixiopsis punctatus (Matsumura) (Hemiptera: Fulgoromorpha: Tropiduchidae) was studied using scanning electron microscopy. Eleven types of sensilla or sensory organs were identified: trichoid sensilla on the pedicel, scape, maxillae, and labium; campaniform sensilla on the antennal pedicel, antennal scape, maxillae, and labium; plate organs on the antennal pedicel; coeloconic sensilla in Bourgoin's organ and styloconic sensilla on the expanded flagellar base; Evans' organ and button-like sensilla on the maxillary plates; basiconic sensilla, peg sensilla, and coin-shaped sensilla on the labium. Styloconic sensilla on the expanded flagellar base and peg sensilla located between the dorsal sensory field and the opening of the maxillae and mandibles were first reported in Tropiduchidae. The external morphology, distribution, and abundance of sensilla located on antennae, maxillae, and labium in C. punctatus were illustrated.