Faunal make-up, host range and infestation rate of weevils and tephritid flies associated with flower heads of the thistleCirsium(Cardueae: Astaraceae) in Japan.

Nakamura, Akinori; Nakamura, Koji

From 1988 to 1998, we collected flower heads of 39 thistle taxa (35 taxa ofCirsium, one species each ofBreea,Synurus,SaussureaandArctium; Cardueae; Astaraceae) in Japan, mainly from Hokuriku and other parts of central Honshu, and kept them in the laboratory to breed weevils and tephritid flies, the core fauna. We report the faunal make-up, host plants, geographic distribution and the attack levels of the insects. Results indicated that (i) threeLarinusspecies (Curculionidae) and three species of tephritid flies (Tephritis,UrophoraandXyphosia) comprised the core fauna; (ii) two insect species belonging to the same taxonomic group (either Curculionidae (Larinus) or Tephritidae) tended to use different host plant species; (iii) two sympatricLarinusspecies (L. latissimusandL. meleagris) segregated the host plants seasonally in central Honshu (Cirsiumblooming in spring and autumn, respectively); and (iv) two tephritid fly species,Xyphosia punctigeraandUrophora sachalinensis, segregated geographically (the former on the Japan Sea side and the latter on the Pacific Ocean side). In comparison with their European counterparts, the weevils and tephritids of the JapaneseCirsiumare characterized by a lower species richness and a lower degree of specialization in usage of the thistle flower heads, with gall-formers being distinctly under-represented, and callus tissue-feeders being absent. This reflects the fact that Japanese thistles are so closely related that hybridization frequently occurs, and also that the thistles have had a short history of interaction with the insects since the thistles’ arrival in Japan.

JAPAN; BEETLES; TEPHRITIDAE; THISTLES; CIRSIUM; HOST plants; FLOWERS

Entomological Science, 2004, Vol 7, Issue 4, p295

1343-8786

Academic Journal

10.1111/j.1479-8298.2004.00077.x