Diaphania angustalis Snellen (Lepidoptera: Crambidae) is the main defoliator of Alstonia schalaris. In this article, observation of external morphological and ultrastructure structure of adult antennae of D. angustalis was carried out using the scanning and transmission electron microscope. The results showed that both male and female antennae were filiform and could be divided into scape, pedicel, and flagellum. There are eight types and two subtypes of antennal sensilla, namely, sensilla trichodea, sensilla chaetica (I & II), sensilla coeloconica, sensilla auricillica, sensilla styloconica, sensilla squamiformia, capitate peg, and Böhm bristles. Most sensilla are concentrated in venter and the sides of antennae. Analyses on morphological and quantitative differences of antennal sensilla between male and female adults. The size of SCo is significantly different between male and female. In terms of quantity, only SSt and CP have no significant differences between male and female. By comparing the existing antennal sensilla of Crambidae, it is found that STr, SCh, SCo, and SAu are common sensilla. These results can contribute to further research on the function of sensilla of D. angustalis relating to its behavior. A detailed description is provided of the antennal sensilla in Diaphania angustalis. Diaphania angustalis has the rare sensilla of capitate peg in Crambidae. No sexual dimorphism of sensillum types is found in the species. The number and distribution of sensilla trichodea, sensilla chaetica, sensilla coeloconica, and sensilla auricillica sensillum are different.

1. Male animals usually raise their sperm allocation after detecting sperm competition risk. To date, only a few studies have investigated the cues used by males to sense

The antennal sensilla of Copidosomopsis nacoleiae (Eady) (Hymenoptera: Chalcidoidea: Encyrtidae) were observed under scanning and transmission electron microscopy in this study. The antennae of C. nacoleiae are geniculate, and the flagellum is composed of five subsegments in males and six in females. Six types of sensilla were observed, including sensilla trichodea, sensilla chaetica, sensilla basiconic capitate pegs, sensilla placodea, sensilla basiconica, and Böhm's bristles. Sensilla trichodea were evenly distributed throughout the antennae. Sensilla chaetica, sensilla basiconic capitate pegs and sensilla placodea were found on the flagellomeres. Sensilla basiconica were only found on the club, and Böhm's bristles were found on the radicle and the pedicel. Sensilla trichodea, sensilla placodea, sensilla chaetica, and sensilla basiconic capitate pegs were found to be the most common sensilla of the parasitoids in the superfamily Chalcidoidea. The external and internal characteristics, types, number, distribution, and dimensions of these sensilla are described, and their possible functions are discussed in accordance with host‐detection behavior. Future studies on the host location mechanisms of C. nacoleiae will be based upon these observations.

Endoclita signifer is a major wood-boring pest of eucalyptus trees in China, and its third instar larvae can accurately find and infest eucalyptus trees in mixed-species forests, although it can also feed on another 51 tree species in the same planted area. A total of 34 volatile compounds were identified from eucalyptus trunks, including non-infested and infested trunks with single or multiple (more than three) larval entrance cover packets, and forest floor humus. Of these, o-cymene showed a strong gas chromatography-electroantennographic detection (GC-EAD) activity and significant attraction of the third instar E. signifer larvae. Higher abundance of alpha-phellandrene, o-cymene, and the unique 2-phenyl-2-propanol in the volatile profile from infested eucalyptus trunks indicated that they were herbivore-induced plant volatiles (HIPVs). The larvae showed significantly higher attraction to volatile blends, especially those from infested eucalyptus trunks, than to single volatiles. A blend of the three HIPVs, α-pinene, D-limonene, and n-butyl ether may serve as an attractant for the control of E. signifer larvae in eucalyptus plantations. Further, exposure of third instar E. signifer larvae to some of these volatiles which also elicited electroantennogram and behavioral responses, influenced expressions of some olfactory proteins. Our results show that third instar E. signifer larvae can recognize o-cymene from host eucalyptus trunks and are attracted to the trunk by the three HIPVs when they shift their habitats from the forest floor humus to the tree trunks.