title: Sexual dimorphism in antennal morphology and sensilla ultrastructure of a pupal endoparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae).
abstract: Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae), a pupal parasitoid of a great number of Lepidoptera pests, has a great potential for biological control. To investigate the olfactory system of this parasitoid, we examined the morphology and ultrastructure of the antennal sensilla of both male and female T. howardi using scanning and transmission electron microscopic techniques. Antennae of male and female T. howardi were geniculate in shape, which consisted of scape, pedicel and flagellum with 5 and 4 flagellomeres, respectively. The sexual differences were recorded in the types, structure, distribution and abundance of antennal sensilla of T. howardi. Fourteen morphologically distinct types of antennal sensilla were found on the female antennae, while seventeen on the male antennae. They were: multiporous plate sensilla (MPS1-4), chaetica sensilla (CH1-3), multiporous trichodea sensilla (MTS), aporous trichodea sensilla (ATS1-5), multiporous grooved peg sensilla (MGPS), coeloconic sensilla (COS), campaniform sensilla (CAS), terminal finger-like hairy sensilla (TFI), cuticular pore (CP), and ventral sensory plaque (VSP). MPS4, ATS (3-5), and VSP only occurred on the male antennae, while MPS2 and MPS3 only on the female antennae. The MPSs, MTS, MGPS, TFI, and CP may function as olfactory sensilla involving in detecting odor stimuli whereas the ATSs, CHs, and CAS may serve as mechanoreceptors. COS were presumed to play a role as chemo-, thermo- or hygro-receptor. The results could facilitate future studies on the biology of olfaction in T. howardi.
authors.affiliation: Laboratory of Insect Ecology, South China Agricultural University, Guangzhou, 510642, China.|Key Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, 510642, China.
authors.forename: Yihua
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: College of Agronomy, Jiangxi Agricultural University, Nanchang, 330045, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Plant Protection Institute, Guangdong Agricultural Science Academy, Guangzhou, 510640, China.
authors.forename: Yonglin
authors.initials: Y
authors.lastname: Liao
authors.affiliation: Laboratory of Insect Ecology, South China Agricultural University, Guangzhou, 510642, China.|Key Laboratory of Bio-Pesticide Creation and Application of Guangdong Province, Guangzhou, 510642, China.
authors.forename: Weijian
authors.initials: W
authors.lastname: Wu
mesh_terms: D000818:Animals; D057506:Arthropod Antennae / Q000648:ultrastructure*; D005260:Female; D006927:Hymenoptera / Q000648:ultrastructure*; D008297:Male; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D058618:Sensilla / Q000648:ultrastructure*; D012727:Sex Characteristics
keywords: SEM; TEM; antennae; antennal sensilla; parasitoid