The Hymenoptera

Hymenoptera

Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...

n superfamily Platygastroidea (sometimes incorrectly spelled Platygasteroidea) has, in the past, often been treated as a lineage within the superfamily Proctotrupoidea

Proctotrupoidea

The Hymenopteran superfamily Proctotrupoidea is a somewhat confusing assemblage of taxa, with new families being added with surprising frequency, and very little to unify them all into a single natural group...

, but most classifications since 1977 have recognized it as an independent group, composed of two families, the Platygastridae

Platygastridae

The Hymenopteran family Platygastridae is a large group of exclusively parasitoid wasps, mostly very small , black, and shining, with elbowed antennae that have an 8-segmented flagellum...

 and the Scelionidae

Scelionidae

The Hymenopteran family Scelionidae is a very large cosmopolitan group of exclusively parasitoid wasps, mostly small , often black, often highly sculptured, with elbowed antennae that have an 9- or 10-segmented flagellum...

, with a combined diversity of some 4000 described species. The two groups are unified by a number of features, the most important of which are shared unique features synapomorphies

Synapomorphy

In cladistics, a synapomorphy or synapomorphic character is a trait that is shared by two or more taxa and their most recent common ancestor, whose ancestor in turn does not possess the trait. A synapomorphy is thus an apomorphy visible in multiple taxa, where the trait in question originates in...

 of the ovipositor

Ovipositor

The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...

 and details of the female antenna

Antenna (biology)

Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....

. They are exclusively parasitic in nature. See families for details.

The former family Scelionidae is now considered to be a subfamily of Platygastridae, along with the subfamilies: Teleasinae and Telenominae.