Farfiugium japonicum [Compositae], called "Tsuwabuki" in Japanese, is an edible perennial plant growing naturally around the edges or inside forests in southwestern Japan. It has traditionally been used for medical or ornamental purposes. In recent years, this plant has been brought under cultivation for food, particularly in southern Kyushu. With increasing use of the plant, fundamental information of associated insects has become necessary to be gathered.
Larvae of the farfugium petiole gall fly (new name), Paratephritis fukaii SHIRAKI, produce elongated spindle-shaped galls on the petiole or peduncle of F. japonicum. Pupation and emergence take place in the gall, and adults come out of the gall through one or two small exit holes produced on its surface. The formation of galls results in losses of the edible petiole production. In order to contribute something to the knowledge of the life history of P, fukaii, the exit holes were surveyed several times a month from April 1989 to March 1990 at the census field in Kagoshima City. The age structure of the gall fly was also examined occasionally by dissecting the galls collected from the station. The field survey, the dissection of galls and other rearing experiments indicated the outline of the life history of this species in Kagoshima City as follows: (1) this gall fly overwintered as pupae and emerged from February to March, (2) adults of the first generation appeared in June, (3) the longevity of adults of the first generation was 18.3±7.4 days in males and 24.7±9.8 days in females, (4) there were 2 or more generations overlapping from June to September, (5) the duration from oviposition to adult escaping was estimated to be 64 days on average in summer, (6) galls were produced also on peduncle in fall, and (7) no adults emerged after September until the following February.
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