Several species of the genus Aphidius are used in biological control programs against aphid pests throughout the world and their behavior and physiology are well studied. While the importance of sensory organs in their behavior is understood, their antennal structure remains largely unknown. In this study, the external morphology and distribution of the antennal sensilla on the antennal of both female and male adults of A. colemani were described using scanning electron microscopy (SEM). Generally, the filiform antennae of males (1,515.2±116.5 ㎛) are longer than females (1,275.1±103.4 ㎛). Antennae of this species are made up of radicle, scape, pedicel and flagellomeres. Male and female antennae differed in the total number of flagellomeres as 15 in males and 13 in females. The result of SEM observation was characterization and grouping of seven types of receptors into morphological classes: Bohm bristles, Sensilla placodea, 2 types of S. coeloconica and S. trichodea, and S. basiconica as with a tip pore and with wall pores. In addition, the possible functions of the above sensilla types are discussed in light of previously published literature, mechanoreception (Bohm bristles, S. coeloconica Ⅰ & Ⅱ and S. trichodea) and chemoreception (S. placodea, S. basiconica type Ⅰ & Ⅱ).
A solitary endoparasitoid, Cotesia plutellae, parasitizes diamondback moth, Plutellae xylostella. It bas been suggested that its antennae are a major sensory organ to search host and recognize host developmental and other physiological condition during parasitization. This research was performed to understand the parasitic behavior of C. plutellae by analyzing sensory types and their numbers on the antennae using scanning electron microscope. There was no significant difference in antennal length in both male and female C. plutellae, in which both sexes had 16 flagellomeres. Three different types of sensilla (trichoid, seta, and placodea sensilla) were located mostly on flagella and analyzed in their density on the different antennomeres. Trichoid sensillum was the major sensory type and showed about 87% density among all sensilla. Both trichoid and placodea types of sensilla exhibited even numbers on all flagellomeres with some decrease at terminal segments. In contrast, seta form of sensilla showed drastic increase in its density at distal part after 9th flagellomere. When distal half of flagellomeres were cut off, the C. plutellae could not parasitize host larvae. Even when only four distal flagellorneres were removed, the parasitism showed only 30%. These results indicate that C. plutellae antennae are required for parasitism and suggest that seta form of sensilla may play significant roles in recognizing host for parasitization.
The antennal receptors of the adult male and female of the American leafminer, Liriomyza trifolii (Diptera: Agromyzidae) was studied using the scanning electron microscopy. This antennal receptors were developed to accept the chemical or mechanical signal in the environment. The antennae of L. trifolii is 317.52 ㎛ long and composed of the scape, pedicel, funicle, arista. Antennae located between compounds eye on the middle in the head. The result of SEM observation, four types of receptors were characterized and grouped into morphological classes: Trichoid, Basiconic, Coeloconic, Chetiform sensilla. Trichoid sensilla are located on the all segment. As a rule, female is more than male. This sensilla are long and slender hair with straight or slightly curved, and taper to a sharp point apically. Basiconic sensilla are observed only on the funicle. The number of basiconic sensilla in male and female are almost same in both sexes. This sensilla are long and thick hair with stright or slightly curved, and taper to a blunt point apically. Coeloconic sensilla are observed only on the funicle. This sensilla were showed a finger-like projections the peg apex. The number of basiconic sensilla in male and female are almost same in both sexes. Chetiform sensilla are located on the all segment. This sensilla are needle-like, tapering sharply. Pedicel are more than scape. The number of Chetiform sensilla in male and female are almost same in both sexes.
주사전자현미경 및 광학현미경을 이용하여 밝혀낸 담배나방(Heliothis assulta Guenee) 유충의 촉각 및 구기의 감각기 구조는 다음과 같다. 촉각은 세마디로 되어있지만 마지막 두마디에만 감각기가 분포하고, 기절은 단순히 촉각을 머리에 부착시킨다. 병절은 2개의 털 감각기와 3개의 방망이형 가각기를 가며, 편절은 3개의 방망이형 감각기와 2개의 2마디로된 방망이형 감각기를 갖는다. 큰 턱은 측면에 2개의 털 감각기를 가지며, 작은턱의 외엽에는 2개의 털, 3개의 방망이형 및 2 개의 종상형 감각기가 있다. 작은 턱 수염의 2마디중 첫째마디는 1개의 digitiform 감각기만을 갖는다. 그러나 둘째마디는 11개의 감각기를 갖는데. 1개의 digitiform 과 2개의 종상형 감각기는 측면에, 8개의 방망이형 감각기는 마디 끝에 위치한다. 윗입술은 외표면에 12개의 털, 내표면에 6개의 털, 2쌍의 함몰형과 1쌍의종상형 감각기를 갖는다. 퇴화된 아랫입술은 작은턱과 융합되어서, 하인두, spinneret, 수염을 지지하며, 이들중 아랫입술염에만 2개의 방망이형 감각기가 있다. 구조적 측면에서 감각기의 기능을 추정해보았으며 구기 전체 감각기의 70%를 차지하는 작은턱 감각기가 먹이 선택 행동에 중요한기능을 할 것으로 보인다.