Morphology of the Brush-Organs of the Limabean Pod Borer, Etiella zinckenella TREITSCHKE : Lepidoptera : Pyralidae

The male limabean pod borer, Etiella zinckenella TREITSCHKE, has a pair of brush-organs on the thorax and on sternite 8, and a scale mass on each of the antennae. The brush-organs on the thorax and the scale mass on the antennae are characteristic of the Phycitinae among the Heterocera. The brush-organs on the thorax arise from the top of a slender sclerotized plate diverging from the episternum of the metathorax, close to the bases of the hindwings. The brushes are white and ca. 3 mm in length. Normally the brushues are hidden between the meso- and metathorax, but they are probably exposed during male courthip, when the male raises his abdomen towards the abdominal end of a calling female. The brushes consist of three types of scales : long, short and cover-like scales. Long scales in the center of the brushes are considered disseminators of males scent because of their porous surface and mesh-like internal structure. The brushes on sternite 8 are extruded, and the scale mass on the antennae touches a calling female, during courtship, but no pores could be found on the surface of either scales. Thus, they seem to have other functions insetead of disseminators of male scent.