Osmylidae are a small
family of
winged insects of the net-winged insect
orderNeuroptera. The osmylids, also called lance lacewings, stream lacewings[1] or giant lacewings[note 1],[2] are found all over the world except North and Central America. There are around 225 extant species.[3]
Description and ecology
Adult osmylids are small to moderately-sized net-winged insects, with wingspans ranging from 1.4 to 3 cm. Smaller members resemble typical
green lacewings, and larger species resemble
antlions. Many species, namely those of the
type genusOsmylus, have spotted wings. The thin
antennae are short. They have two
compound eyes, as well as three
ocelli in between. Adult osmylids, like green lacewings (some of which are colloquially known as "stinkflies"), have
prothoracal glands which produce foul-smelling compounds used to deter would-be
predators.
Their
larvae are superficially similar to those of spongillaflies (
Sisyridae). They have peculiar
mouthparts which look like a thin
forceps with the ends bending outwards. The body is elongated and slender and terminates in two extensible graspers bearing tiny hooks; these are used to aid in locomotion and to grasp prey. The larvae are associated with damp, mossy habitats and are
amphibious. They hunt small invertebrate prey, from which they suck the body fluids with their mouthparts.
The adults are
diurnal or
crepuscular weak-flying insects which mostly prey on small
invertebrates, supplemented with some
pollen. Eggs are deposited in damp places, usually near
freshwater.
Osmylids are generally placed with the extant families
Sisyridae (spongillaflies) and
Nevrorthidae within the clade Osmyloidea, which is the second earliest diverging clade of Neuroptera after
Coniopterygidae (dustywings). The group also contains
Archeosmylidae from the Permian-Triassic and
Saucrosmylidae from the Middle Jurassic, both of which are thought to be closely related to Osmylidae. The earliest records of Osmylidae date to the Early Jurassic, some of which are already assignable to extant subfamilies, and were diverse during the Jurassic and Cretaceous. At least 278 species have been described in 25 extant and 38 extinct genera.[4]
The following subfamilies and genera are largely after Winterton et al., 2019[4]