Ag. Wheeler et Ca. Stoops, ESTABLISHMENT OF UROPHORA-AFFINIS ON SPOTTED KNAPWEED IN PENNSYLVANIA, WITH NEW EASTERN US RECORDS OF UROPHORA-QUADRIFASCIATA (DIPTERA, TEPHRITIDAE), Proceedings of the Entomological Society of Washington, 98(1), 1996, pp. 93-99
The Old World tephritid Urophora affinis (Frauenfeld) is a gall-induci
ng seedhead fly released in western and eastern North America for the
biological control of knapweeds, Centaurea spp. (Asteraceae). Its esta
blishment and spread in the West are well documented, but recoveries i
n the East have been few: in New York near release sites in Essex and
Warren counties and at unspecified localities in Quebec and Virginia (
presumably at or near release sites). Urophora affinis is reported as
a new state record from Pennsylvania (7 counties), and its establishme
nt in central New York State is recorded. Urophora quadrifasciata (Mei
gen), another Palearctic species introduced for knapweed control, is r
ecorded for the first time from Maryland, Virginia, and West Virginia,
and its known range in Pennsylvania is extended.