Abai, MR

6th International Congress of DipterologyGoldenrod gall midges revisited: cecidomyiid biodiversity onSolidago and Euthamia (Asteraceae) in North AmericaDorchin, N & W.G. AbrahamsonDepartment of Biology, Bucknell University, Lewisburg PA, 17838, USAGoldenrods are hosts to 24 recorded species of gall-inducingcecidomyiids in North America, making these plants one the most speciesrichhost taxa for gall midges, second only to Artemisia among theAsteraceae. While much ecological research has been done on some of thegoldenrod-infesting midges, most species are only superficially known,several seem to be synonymous, and some have not been found since theirdescription almost 100 years ago. The major cecidomyiid generaassociated with goldenrods are Rhopalomyia, Asteromyia, and Dasineura,which account for 16, 4, and 4 described species, respectively. The generaAsphondylia, Lasioptera, and Schizomyia are each represented by 1-2described species. Galls induced by these species are found on most plantorgans, from rhizomes to stems, leaves, buds, and flowers, and exhibitgreat diversity in size, shape and structure. However, the life history ofmost species is virtually unknown.Along with studies focused on behavioral ecology and systematics ofcertain species in this group, we conducted a field survey of goldenrod gallmidges in an attempt to rear little-known species and learn about theirbasic biology. This survey has yielded numerous new host and gall records,which might prove to represent undescribed species, especially in thegenus Asphondylia. Life-history data gathered elucidate complex lifecycles in Rhopalomia and Dasineura spp., including induction of differenttypes of galls at different times of the year, and the occurrence of naturalenemies. While the large number and biological diversity of goldenrod gallmidges make them ideal models for evolutionary ecology and systematicstudies, lack of knowledge of their basic biology and taxonomy hashindered such research. The information we are gathering will not onlylead to a better understanding of basic life-history strategies of the gall63