Morphology and distribution of antennal sensilla of two tortricid moths,Cydia pomonellaandC. succedana(Lepidoptera)

Abstract

Morphology of antennal sensilla and their distributions were investigated in male and female adults of two tortricid moths, Cydia pomonella and C. succedana using scanning electron microscopy. The antennae of both sexes of the two species were filiform, and the overall lengths of the antennae and the number of consisting segments were greater in males than in females. Six types of sensilla (s.) were identified from the antennae of both sexes in the two species: s. trichodea, s. basiconica, s. coeloconica, s. auricillica, s. chaetica, and s. styloconica, in varying numbers and distribution along the antennae. Among them, surface of four sensilla types (s. trichodea, s. basiconica, s. coeloconica, s. auricillica) were multiporous in the two species, indicating that the primary function of these sensilla is olfactory. The s. trichodea were the most numerous on the antennae in both sexes of the two species. Male C. pomonella has a greater number of s. trichodea than the female. The four sensilla types were further divided into different subtypes in the two species; s. trichodea into three subtypes, s. basiconica into two subtypes, s. coeloconica into two subtypes in C. pomonella and one subtype in C. succedana, and s. auricillica into two subtypes. Sexual dimorphism was observed in the subtypes of s. trichodea. The long subtype of s. trichodea occurs only on male antennae, whereas the short subtypes mainly on female antennae. These findings would be helpful for further studies on detailed chemo-receptive functions of each subtype of the antennal sensilla.

Morphological and functional heterogeneity in olfactory perception between antennae and maxillary palps in the pumpkin fruit fly, Bactrocera depressa

“…It has been suggested that the wall‐pores and longitudinal grooves are the entry points of odor molecules into the sensillum lumen (Maitani, Allara, Park, Lee, & Baker, ; Shields & Hildebrand, ; Steinbrecht, ; Zacharuk, ). Our study indicated that multiple nanoscale wall‐pores are present in trichoid and basiconic sensilla of male and female B. depressa , suggesting that their sensory function is olfactory, as demonstrated in other dipteran species such as P. tricuspis (Chen & Fadamiro, ), P. terraenovae (Setzu et al, ), and Stomoxys calcitrans (Muscidae; Tangtrakulwanich et al, ) as well as in other groups of insects (Roh et al, ; Wee et al, ). Extracellular recordings from coeloconic sensilla in some insect species have shown that their main function is olfactory (Hallberg et al, ; Pophof, ; Pophof et al, ; Yao et al, ), therefore, the main function of the coeloconic sensilla in the antennae of B. depressa is suggested to be olfactory.…”

“…Despite diverse external morphology, the olfactory sensilla in insects usually share a common feature containing multiple nanoscale wall‐pores (Kim et al, ; Onagbola & Fadamiro, ; Roh et al, ; Wee, Oh, & Park, ). An exception is coeloconic sensilla, which exhibit longitudinal grooves instead of multiple wall‐pores (Diongue, Yang, & Lai, ; Faucheux, Kristensen, & Yen, ; Roh et al, ).…”

“…Despite diverse external morphology, the olfactory sensilla in insects usually share a common feature containing multiple nanoscale wall‐pores (Kim et al, ; Onagbola & Fadamiro, ; Roh et al, ; Wee, Oh, & Park, ). An exception is coeloconic sensilla, which exhibit longitudinal grooves instead of multiple wall‐pores (Diongue, Yang, & Lai, ; Faucheux, Kristensen, & Yen, ; Roh et al, ). It has been suggested that the wall‐pores and longitudinal grooves are the entry points of odor molecules into the sensillum lumen (Maitani, Allara, Park, Lee, & Baker, ; Shields & Hildebrand, ; Steinbrecht, ; Zacharuk, ).…”

“…Members of each taxonomic group of insects appear to share some characteristic morphological types of antennal olfactory sensilla (Bleeker, Smid, Aelst, van Loon, & Vet, ; Chinta et al, ; Ploomi et al, ; Roh, Park, Oh, & Park, ). In addition to the well‐developed olfactory sensilla in the antennae, the maxillary palps also contain a number of olfactory sensilla in different groups of insects, although their functional significance in most species is not well understood.…”

Olfactory attraction mediated by the maxillary palps in the striped fruit fly, Bactrocera scutellata: Electrophysiological and behavioral study

“…The antennae are the major olfactory sensory organ in insects, housing various types of olfactory sensilla of which olfactory function can be morphologically characterized as having multiple cuticular pores (Chen & Fadamiro, ; J. Kim et al, ; Onagbola & Fadamiro, ; Roh, Park, Oh, & Park., ; Setzu, Poddighe, & Angioy, ; Wee, Oh, & Park, ; Zacharuk, ). Pheromones and other semiochemicals are mainly detected by the olfactory sensilla in the antennae of insects (Baker et al, ; Larsson, Leal, & Hansson, ).…”