Objective To determine the type, distribution and quantity of sensilla on antennae and mouthparts of the first instar larvae of Dastarcus helophoroides.

Method The first instar larvae of D. helophoroides were selected within 12 h of hatching. After pretreatment, field emission scanning electron microscopy (FESEM) was used to observe sensilla.

Result The head of the first instar larvae of D. helophoroides consisted of a pair of antenna, a pair of mandible, a pair of maxilla and a pair of labium. The antennae are filamentous, consisting of scape, pedicel and flagellum. A Bohm’s bristle was distributed on the scape, one sensilla pit basiconica, one sensilla basiconica Ⅰ and three sensilla basiconica Ⅱ were distributed on the pedicel. None of the sensilla was distributed on the flagellum. The mouthparts were prognathous and chewing-lapping type, there were one sensilla trichodea and one Bohm’s bristle on the mandible. The labium had nine digitiform sensilla and the maxilla has six digitiform sensilla.

Conclusion Antenna and mouthpart of the first instar larvae of D. helophoroides have five types of sensilla, a total of 23, including physical sensilla and chemical sensilla. The digitiformsensilla are distributed in clusters, the other sensilla shows a scattered distribution.