AntennAl sensillA of pArthenogenetic And bisexuAl Lissorhoptrus oryzophiLus (coleopterA: curculionidAe)

Antennal sensilla were compared in parthenogenetic females and bisexual adults of rice water weevil, Lissorhoptrus oryzophilus Kuschel (coleoptera: curculionidae), using scanning electron micrographs. the antenna of parthenogenetic females and of both sexes of bisexual reproductive weevils consisted of the scape, pedicel, and 6 flagellar segments. females, regardless of mode of reproduction, had longer antennal segments than males. the 3 adult forms/genders can be correctly classified into their respective groups with a set of discriminant mathematical functions based on 4 morphological measurements of length or maximum width of segments of the antennae. for both sexes, 6 morphological sensilla types were found on the antennae, including hydrofuge scales i (hsi), trichoid sensilla (ts), 2 types of squamiform sensilla (ssi, ssii), tuft hairs (th), and böhm bristles (bb). no remarkable sexual differences in the types or distribution of sensilla were found on the antennae among parthenogenetic and both sexes of bisexual reproductive weevils, except for hsi. both the length and basal diameter of hsi of females were significantly greater than those of the males. the hsi of the parthenogenetic females were significantly longer than those of the bisexual females. the numbers of branches of hsi on the sixth flagellum of the parthenogenetic females were significantly more than on both sexes of bisexual adults. the numbers of branches of hsi of the females were significantly more than those of the males. from the information gained from this scanning electronic microscope study of antennae, we can separate rice water weevils by gender and reproductive mode.