Scanning Electron Microscopy(SEM) Observations of Antennal Sensilla of Chrysopa pallens Rambur(Neuroptera:Chrysopidae)

[Objectives]The paper was to provide background information for ongoing research on relationship between smell and behavior of the green lacewing Chrysopa pallens( Rambur)( Neuroptera: Chrysopidae). [Methods]The submicroscopic structure of antennal sensilla of C. pallens was examined using scanning electron microscopy. [Results]Antennae of female and male C. pallens were linear in shape and( 1. 52 ± 0. 08) and( 1. 58 ± 0. 23) cm in length,respectively. The scape and pedicel were composed of single sub-segment,while the flagellum consisted of 116 sub-segments,on which most sensilla distributed. The flagella of female and male antennae were( 1. 44 ± 0. 04) and( 1. 47 ± 0. 13) cm in length,respectively. Nine morphological sensilla types were recorded in both sexes,including four types of highly abundant and widely distributed sensilla trichodea( ST Ⅰ,ST Ⅱ,ST Ⅲ and ST Ⅳ),three types of sensilla basiconica( SB Ⅰ,SB Ⅱ,and SB Ⅲ),and one of each type of sensilla chaetica and B9 hm bristles. Although the shape,structure,numbers,and distribution of antennae of females and males were basically similar,major differences were recorded between the sexes in the length of some sensilla types. Both the ST Ⅲ and SB Ⅰ in female adults were significantly longer than that in male ones. Notably,SB Ⅱ was found only in female. [Conclusions]The paper laid a foundation for revealing the relationship between smell and behavior,playing a crucial role in promoting the important biological control effect of C. pallens in farmland ecological system.