Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay their eggs. The name is associated especially with the Tenthredinoidea, by far the largest superfamily in the suborder, with about 7,000 known species; in the entire suborder, there are 8,000 described species in more than 800 genera. Symphyta is paraphyletic, consisting of several basal groups within the order Hymenoptera, each one rooted inside the previous group, ending with the Apocrita which are not sawflies.
The Orussidae or the parasitic wood wasps represent a small family of sawflies ("Symphyta"). Currently, about 93 extant and four fossil species are known. They take a key position in phylogenetic analyses of Hymenoptera, because they form the sister taxon of the megadiverse apocritan wasps, and the common ancestor of Orussidae + Apocrita evolved parasitism for the first time in course of the evolution of the Hymenoptera. They are also the only sawflies with carnivorous larvae.
The superfamily Siricoidea is an archaic group of the order Hymenoptera, consisting of six families of xylophagous sawflies. The group is well represented in early Tertiary and Mesozoic times, but a number of living taxa remain, including the family Anaxyelidae, which has recently been linked to this group. The female ovipositor is typically long and projects posteriorly, and is used to drill into wood.
Anaxyelidae is a family of incense cedar wood wasps in the order Hymenoptera. It contains only one living genus, Syntexis, which has only a single species, native to Western North America. Fossils of the family extend back to the Middle Jurassic, belonging to over a dozen extinct genera, with a particularly high diversity during the Early Cretaceous. Syntexis lay eggs in the sapwood of conifers, preferring recently burnt wood.
The Xyelidae are a comparatively species-poor family of sawflies comprising about 80 extant species in five genera worldwide and is the only family in the superfamily Xyeloidea. The fossil record of the family is extensive, comprising more than 120 species and including the oldest fossil Hymenoptera species dating back to the Triassic, between 245 and 208 million years ago. Xyelidae are to be regarded as living fossils since they represent one of the oldest lineages of insects and include still extant forms.
The Pamphilioidea are a small superfamily within the Symphyta, containing some 250 living species restricted to the temperate regions of Eurasia and North America. These hymenopterans share the distinctive feature of a very large, almost prognathous head, which is widest ventrally.
Argidae is a large family of sawflies, containing some 800 species worldwide, primarily in tropical regions. The larvae are phytophagous, and commonly can be found feeding in groups, though very few attain pest status.
Cimbicidae is a family of sawflies in the order Hymenoptera. There are more than 20 genera and 200 described species in Cimbicidae. Larvae are solitary herbivores.
The Diprionidae are a small family of conifer-feeding sawflies restricted to the Northern Hemisphere, with some 140 species in 13 genera. Larvae are often gregarious, and sometimes there can be major outbreaks, thus these sawflies can be major forest pests at times. These sawflies have the ability to compromise the health and ecological balance of forests. When the temperatures begin to rise, the sawflies become strengthened pests to these conifers. In doing so, they cause damage to a certain extent.
Tenthredinidae is the largest family of sawflies, with well over 7,500 species worldwide, divided into 430 genera. Larvae are herbivores and typically feed on the foliage of trees and shrubs, with occasional exceptions that are leaf miners, stem borers, or gall makers. The larvae of externally feeding species resemble small caterpillars. As with all hymenopterans, common sawflies undergo complete metamorphosis.
Trigonalidae is one of the more unusual families of hymenopteran insects, of indeterminate affinity within the suborder Apocrita, and presently placed in a unique superfamily, Trigonaloidea, and the only extant taxon in the superfamily. The other putative related taxon is the extinct family Maimetshidae, known from the Cretaceous period. Trigonalidae are divided into 2 subfamilies; Orthogonalinae and Trigonalinae. These wasps are extremely rare, but surprisingly diverse, with over 90 species in 16 genera, and are known from all parts of the world. It is possibly the sister group to all Aculeata.
Acantholyda is a genus of sawflies.
Nematinae is a subfamily of sawflies belonging to the family Tenthredinidae. It contains over 1250 described species in ~40 genera. Members of this subfamily feed on a wide range of plants and employ a wide range of feeding habits, both internally and externally, on their host plants.
Allantinae is a subfamily of sawflies in the family Tenthredinidae, and the largest subfamily of that family, with about 110 genera. The subfamily is considered to consist of five to six tribes, and are medium to large sawflies.
Cephidae is a family of stem sawflies in the order Hymenoptera. There are about 27 genera and more than 160 described species in Cephidae.
Cimbex quadrimaculatus is a species of sawflies in the family Cimbicidae.
Monostegia is a genus of sawfly. The authority is based on the description by Achille Costa and Oronzio Costa, although earlier work grants this to Fabricius 1798., though the commonest species, M. abdominalis, bears the authority of Fabricius.
Thynnoidea is a superfamily of hymenopterans in the order Hymenoptera. There are at least 2 families and about 10 described species in Thynnoidea.
Karatavitidae is an extinct family of sawflies, known from the Jurassic period, they are the only members of the superfamily Karatavitoidea. While once proposed to be grouped with the Orussoidea in the infraorder Orussomorpha, they are now considered to be the closest relatives of clade containing Orussoidea and Apocrita. There are about 7 genera in Karatavitidae.
Fenusa pumila, the birch leafminer, is a species of sawfly in the family Tenthredinidae. It is found in Europe and has been introduced into North America.
