Ultrastructure of the Sensilla on Larval Antennae and Mouthparts of the Simao Pine Moth, Dendrolimus kikuchii Matsumura (Lepidoptera: Lasiocampidae)

Abstract

The ultrastructure of sensilla on the antennae and mouthparts of Dendrolimus kikuchii Matsumura caterpillars was investigated using scanning electron microscopy. The following sensilla were found on the antennae: a) three sensilla basiconica and two sensilla chaetica on the pedicel; b) one sensillum styloconicum and three sensilla basiconica on the flagellum. The mouthparts bear a variety of sensilla. The labrum bears six pairs of sensilla chaetica. The epipharynx bears three pairs of flattened sensilla chaetica, a pair of sensilla digitiformia, and three pairs of epipharynx sensilla. Each mandible has eight teeth and two sensilla chaetica on the ventrolateral corner. The maxillae have three sensilla chaetica on the dorsolateral surface of the cardo, four sensilla basiconica and two sensilla styloconica on the galea, and one sensillum chaeticum on the stipes. Each maxillary palp has eight sensilla basiconica, three sensilla placodea, and one sensillum digitiformium. The labial palp possesses one sensillum styloconium and one sensillum chaeticum on the distal surface. The distribution of sensilla on the antennae and mouthparts of D. kikuchii were compared with those of other lepidopterous larvae. Roles of the sensilla are discussed based on previous studies.