Four sympatric tortricid (Lepidoptera) species in New Zealand, Epiphyas postvittana (Walker), Planotortrix octo (Dugdale), Cydia pomonella (L.), and Cydia succedana (Denis and Schiffermüller), were studied for the morphology of antennal sensilla and the chemical communication systems using scanning electron microscopy (SEM), electro-antennogram (EAG), gas chromatography-electroantenno-detection (GC-EAD), single sensillum recording (SSR) and field tests. Antennal flagella of adult have four main types of olfactory sensilla (s.); s. trichodea, s. basiconica, s. auricillica, and s. coeloconica in the four species. The s. trichodea subtype I was longest and male-specific in all the species. The antennae of males of the four species showed characteristic higher EAG, GC-EAD and SSR responses to 12, 14-carbon acetates or alcohol. Some of the selected chemicals selected from the electrophysiological experiments caused significant antagonistic or agonistic activities to the sex pheromone of each species in the field. In this study, the four species showed distinct chemical communication systems according to sub-family, which possibly serve as a factor in species isolation.

Insect antennae play important roles in finding mates and in locating food source and oviposition sites. Riptortus pedestris is an important pest of soybean and sweet persimmon in Korea. The male R. pedestris adult produce the aggregation pheromone attracting the conspecific nymphs and both sexes of adults. The pheromone was known as a cue for food finding, but the 1st instar nymph can develop to the 2nd instar without food. This phenomenon may suggest that the 1st instar nymph may have different sensilla system from other instars. Thus, we investigated the morphology and distribution of antennal sensilla and antennal response to the aggregation pheromone (AG) of each nymphal stage using Scanning Electron Microscope (SEM) and Electroantennography (EAG). As expected, first instar nymph did not have sensilla trichodea 3 (T3) and chaetica 3 (Ch3) which existed in other instar nymphs. The antennae of the 1st instar nymph did not responded to AG, with no difference from control. For further elucidation of the functions of sensilla T3 and CH3, single sensillum recording to AG will be done.

Sensory system of insect is important for their fitness in the environment. Riptortus pedestris (Hemiptera: Alydidae) is a major pest of bean plants and some fruit trees in Korea, Japan, China, and South Asian countries. This study was conducted to investigate morphology and distribution of antennal sensilla of R. pedestris, using scanning electron microscopy. Antennae of R. pedestris was 11 and 9.84 mm in length in male and female, respectively, and consists of four segments; scape, pedicel, flagellum 1 and 2 (F1 and F2). Five types of sensilla (s.) trichodea, four types of s. basiconica, two types of s. chaetica, and one type of s. coeloconica were preliminary identified in both sexes of adult R. pedestris, based on their size, shape, presence of socket and surface structure. Three types of trichoid sensilla, four types of basiconic sensilla, one type of chaetic sensilla and coeloconic sensilla had numerous pores along the surface of the sensilla, suggesting their olfactory function. Eight types of sensilla (3 trichoid, 2 basiconic, a chaetic and a coeloconic) showed a distinct socket structure at the base of each sensillum. Different types of sensilla showed different distribution along the antennal segments. Two types of trichoid sensilla and two types of basiconic sensilla were distributed on scape, pedicel and F1 flagella subsegment. However, the distribution of eight other types of sensilla was limited to one of two flagella subsegments.

Insecticidal and repellent activity of sandalwood oil (Santalum austrocaledonium) and its components was tested against cotton aphid , Aphis gossypii in laboratory and field. The activity was estimated by calculating survival rate of aphid after application of sandalwood oil and its components. Analysis by gas chromatography-mass spectrometry led to identification of 5 compounds, alpha-santatol, bergamotol, epi-beta-santalol, and beta-satalol. The components of sandalwood oil was isolated by column chromatography for testing insecticidal and repellent activity. Santalol showed strong insecticidal and repellent activity as a commercial insecticide, imidachloprid. Sandalwood oil and isolated alpha-santatol and beta-santatol also showed strong insecticidal and repellent activity, however there was no significant difference among them.