Occurrence of two pest gall midges, Obolodiplosis robiniae (Haldeman) and Dasineura gleditchiae (Osten Sacken) (Diptera: Cecidomyiidae) on ornamental trees in Sweden

In 2008, Dasineura gleditchiae (the honey locust pod gall midge) and Obolodiplosis robinia (the black locust gall midge) were found for the first time in Sweden (Skaane). Both species originate from North America and both form leaf galls. O. robinia forms marginal leaf roll galls on robinia (Robinia pseudoacacia L., Fabaceae) and the larvae of D. gleditchiae induce globular or pod-like leaflet galls on gleditsia (Gleditsia triacanthos L., Fabaceae). We successfully used sex pheromone traps to monitor and compare the swarming of D. gleditchiae in Alnarp, Sweden on one thorned and one thornless gleditsia variant.