@article {932, title = {Variation in selection pressures on the goldenrod gall fly and the competitive interactions of its natural enemies}, journal = {Oecologia}, volume = {79}, year = {1989}, month = {1989///}, pages = {15 - 22}, author = {Abrahamson,W.G. and Sattler,J.F. and McCrea,K.D. and Weis,A.E.} }