On a Polyhedral Disease of Trichiocampus viminalis (Fall.) Larvae (Hymenoptera: Tenthredinidae)

The poplar sawfly, Trichiocampus viminalis Fall., is indigenous to Europe, where it is common and widespread, but is also prevalent in the north-eastern United States, Eastern Canada and British Columbia. For the past five or six years it has caused serious defoliation to Populus nigra and P. deltoides in the vicinity of Quebec City.