''Euderus set'', the crypt-keeper wasp, is a tiny

chalcid wasp Chalcid wasps (, , for their metallic colour) are insects within the superfamily Chalcidoidea, part of the order Hymenoptera. The superfamily contains some 22,500 known species, and an estimated total diversity of more than 500,000 species, me ...

from the family

Eulophidae The Eulophidae are a large family of hymenopteran insects, with over 4,300 described species in some 300 genera. The family includes the genus ''Elasmus'', which used to be treated as a separate family, "Elasmidae", and is now treated as a subf ...

from the United States, described in 2017 as a

parasitoid In evolutionary ecology, a parasitoid is an organism that lives in close association with its host (biology), host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionarily stable str ...

of the

gall wasp Gall wasps, also incorrectly called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this generall ...

Bassettia pallida ''Bassettia pallida'' is a species of gall wasp found in the Southern United States. This species was described by American entomologist William Harris Ashmead in 1896. ''B. pallida'' reproduces asexually in galls it induces on oak trees. The ...

'', and the description of its life cycle attracted widespread publicity.

Description

The predominant colour of the adult wasp is metallic green to turquoise to

iridescent Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterfl ...

blue, depending on age, with a yellow scape and white tarsi which have a dark brown terminal segment. Females are 1.6mm to 2.3mm in length, males are 1.2mm to 1.6mm. One of the parasitologists to describe the species was Kelly Weinersmith.

Distribution and habitat

The type locality of ''Euderus set'' was Inlet Beach, Florida and it has since been recorded throughout the midwestern, southcentral and southeastern United States. Specimens have been collected from galls on oaks from several subsections of the genus ''

Quercus An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably '' ...

.''

Biology

The female ''Euderus set'' searches for the

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to be ...

s or "crypts" induced by the

gall wasps Gall wasps, also incorrectly called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this genera ...

Andricus quercuspetiolicola ''Andricus quercuspetiolicola'', also called the oak petiole gall wasp, is a species of Cynipini, oak gall wasp in the Family (biology), family Gall wasp, Cynipidae. Galls in which the larvae live and feed are formed along the midrib or Petiole ( ...

'', and possibly others. The female ''E. set'' then oviposits in the chamber of the gall. When the egg hatches, the larva of ''E. set'' burrows into the larva of host wasp. It then manipulates the host so that it speeds up its development,

metamorphoses The ''Metamorphoses'' ( la, Metamorphōsēs, from grc, μεταμορφώσεις: "Transformations") is a Latin narrative poem from 8 CE by the Roman poet Ovid. It is considered his ''magnum opus''. The poem chronicles the history of the wo ...

into an adult and chews its way up to the surface months earlier than normal. When the host does this, the burrow is not wide enough for it to emerge from the stem and its head becomes stuck. The ''E. set'' larva then consumes the host and chews through its head to emerge as an adult. The larvae overwinter in the gall, eating the host, and emerge in the following spring. The mechanism used to manipulate the host is not known. If the adults of ''E set'' have to excavate their own exit tunnel through the plant tissue themselves, they are three times more likely to die than are those that have the host excavate the tunnel for them. ''E. set'' appears to be most closely related to ''Euderus crawfodii'' and ''E. multilineata'', in the sub-genus ''Neoeuderus'', together with another wasp which is a

of a pin oak gall wasp. The wasps in the sub-genus ''Neoeuderus'' appear to be specialist parasitoids of the gall wasps of the family

Cynipidae Gall wasps, also incorrectly called gallflies, are hymenopterans of the family Cynipidae in the wasp superfamily Cynipoidea. Their common name comes from the galls they induce on plants for larval development. About 1,300 species of this genera ...

Naming

The specific name is the name of the Egyptian god

Set Set, The Set, SET or SETS may refer to: Science, technology, and mathematics Mathematics *Set (mathematics), a collection of elements *Category of sets, the category whose objects and morphisms are sets and total functions, respectively Electro ...

, who trapped his brother

Osiris Osiris (, from Egyptian ''wsjr'', cop, ⲟⲩⲥⲓⲣⲉ , ; Phoenician: 𐤀𐤎𐤓, romanized: ʾsr) is the god of fertility, agriculture, the afterlife, the dead, resurrection, life, and vegetation in ancient Egyptian religion. He was ...

in a sarcophagus before killing him and cutting him up into little pieces.

References

{{Taxonbar, from=Q29540541 Eulophidae Insects described in 2017 Hymenoptera of North America