RES Handbook Vol 6 Part 2b. Hymenoptera - Symphyta

Tenthredinidae is the predominant sawfly family in almost all parts of the world except Australia, where it is mainly replaced by PERGIDAE. There are already more than 4,000 species in over 250 genera grouped into 5 sub- families; there are some 8-900 species known from Europe and over 380 from Britain. The predominance of this family over all the others increases northwards in the northern hemisphere; taking the world sawflies the proportion of species of Tenthredinidae to species of all other families together is about 3:1; in Britain it is about 5:1.