Systoloneura geometropis

Description

Systoloneura geometropis is a moth of the family Gracillariidae. It is known from Hong Kong, Taiwan and Japan (Honshū, Kyūshū, Satunan and Shikoku). The wingspan is 4.5-6.2 mm. The larvae feed on Gardenia augusta, Gardenia jasminoides and Gardenia radicans. There are four instars in larval period, the first two are of sap-feeding type with a flat head, and the last two are of tissue-feeding type with a round head and a cylindrical body as in Aristaea species. First instar larva mine the lower layer of spongy parenchymal tissues and makes a short linear mine along the vein. A short time after it broadens the mine into a blotch. In the second instar, it continues to make a blotch-mine, which finally occupies a more or less full area between two branching veins. In the third and fourth instars the larva, with tissue-feeding mouthparts, feeds on the remaining tissues within the blotch-mine. When fully grown, it leaves the mine through an exit hole to pupate. In this stage the mine is tentiformed, with a strong longitudinal wrinkle on the lower side. Pupation takes place inside a whitish, boat-shaped cocoon which is usually located on the lower surface of the leaf near the apex. At the spinning site the leaf is always folded downwardly.