Surface structures of the antenna of Mantophasmatodea (Insecta)

The cuticular fine structure of the antenna in Mantophasmatodea (Austrophasmatidae: Hemilobophasma montaguense, Austrophasma gansbaaiense) is described based on SEM images. The armature of sensilla (=s.) on the basiflagellum (14 basal flagellomeres, the distal ones of which are subdivided) and distiflagellum (7 distal flagellomeres) differs strongly. A basiflagellomere has a sporadic vestiture of prominent s. chaetica B as well as distal s. scolopidia and scattered s. coeloconica. The distiflagellum also bears scattered s. chaetica B and s. coeloconica but is also densely covered with sensilla of various other types: numerous s. trichodea and s. basiconica, sporadic s. coelocapitula, and a probably new type of branched sensilla; the distiflagellum is probably the main sensory region, including gustatory and olfactory chemoreception, mechanoreception, and hygroreception. The scape and pedicel also bear s. chaetica B, and s. chaetica A arranged in 4 (scape) or 2 (pedicel) hair-plates. Terminal s. campaniformia are only found on the pedicel. A ‘dark spot’ is present apically on distiflagellomeres 6 (as reported previously) and 1. The two spots are of similar structure and are possibly associated with glands; each comprises a complicated external aperture and a larger internal pouch enclosing a cavity; projections protrude from the pouch walls into the cavity. The surface structure of the basiflagellomeres shows differences that are possibly species specific. An overview is given on antennal apomorphies in Mantophasmatodea.