Euplectrus is a cosmopolitan genus and are easily distinguished from other members of the subfamily Eulophinae by three characteristics i.e. the hind tibial spurs are very long and strong with the longest spur being no less than half as long as hind tarsus and is used to anchor the female wasp to the dorsum of the host caterpillar during oviposition; the scutellum has no lateral grooves or pit-rows; and propodeum has a single strong median carina.

[1] Euplectrus wasps have been found as parasitoids on the caterpillars of the families Erebidae, Euteliidae, Geometridae, Lasiocampidae, Noctuidae, Nolidae, Notodontidae, Sphingidae and Tortricidae.

[2][1] The larvae of all species of Euplectrus are greenish-yellow and are very obvious on the host caterpillar's cuticle to which they are very firmly attached.

[1] The larvae of the wasps in the genus Euplectrus are external parasitoids of the caterpillars of various species of Lepidoptera.

The larva undergoes 3–5 molts before pupation and the development from oviposition to imago is normally no longer than two weeks.