Sawflies are exciting first captures of spring. As soon as most of the snow is gone, many sawflies fly over a tan and gray landscape, to be caught by enthusiastic hymenopterists.
Sawflies as larvae are generally significant defoliators of important agricultural crops and trees (see section entitled "Economic Importance"). In Canada we are endowed with a rich sawfly fauna. At present 705 species are recorded in this country, and an additional 150 species that occur in the northern United States are expected to be found eventually in Canada. An unknown but no doubt large number of undescribed species also await discovery. The known Canadian species are divided into 121 genera.
Sawflies are members of the suborder Symphyta, and adults are easily distinguished from those of all other Hymenoptera by the broad joint between the abdomen and the thorax and by the first tergum clearly associated with the abdomen rather than with the metathorax. Sawflies are divided into 14 families, 12 of which are recorded in Canada. Of these families Tenthredinidae is the largest in number of species (565) and genera (89).