Diprionidae: Brief Summary
provided by wikipedia
The Diprionidae are a small family of conifer-feeding sawflies (thus the common name conifer sawflies, though other Symphyta feed on conifers) restricted to the Northern Hemisphere, with some 90 species in 11 genera worldwide. Larvae are often gregarious, and sometimes there can be major outbreaks, thus these sawflies can be major forest pests at times.
The family is distinctive in having antennae with about 20 flagellomeres, and serrate or pectinate.
Sawfly infestation in Scots pines
provided by Catalog of Hymenoptera in America North of Mexico
A small family found in the coniferous forests of the Northern Hemisphere with about 91 world species in 11 genera. Though more common in the cool northern regions, representatives are found as far south as north Africa, Pakistan, north India, Thailand, El Salvador, and Cuba. Hosts are restricted to conifers; consequently, they are commonly called conifer sawflies. Larvae defoliate the host, and sporadic outbreaks may occur in forest stands resulting in loss of growth and sometimes tree mortality. Many are also a nuisance in plantations, nurseries, and ornamental plantings. All larvae feed on the needles except for those of Augomonoctenus libocedrii Rohwer which feeds in the developing cones of incense cedar. In addition to the foliage, some may also feed on the tender bark of new twigs. Most larvae are gregarious at first but later disperse on the tree in search of new food. Overwintering is either as an egg in the needles or as a prepupa in a cocoon in the forest litter. Adults are short-lived and are most easily obtained by rearing. Depending on the species and sometimes the latitude, there may be from one to five generations a year; however, sometimes it takes more than one year to complete a life cycle. Diapause is common in many species. ~Because this is an economically important group, literature references are numerous. The literature cited here for many species is not complete and would take many more pages. Some early literature, expecially prior to 1943, is not reliable because the taxonomy has changed to such an extent that it is impossible to tell to which species the articles refer. The taxonomy of some groups, Neodiprion in particular, is still flexuous.