Dolichogenidea xenomorph, the Alien-wasp

Views of a Dolichogenidea xenomorph specimen (Image courtesy Erinn Fagan-Jeffries. All rights reserved)
Views of a Dolichogenidea xenomorph specimen (Image courtesy Erinn Fagan-Jeffries. All rights reserved)

An article published in the “Journal of Hymenoptera Research” describes the discovery of some new species of parasitoid wasps endowed with particularly long ovipositors. The most interesting one was named Dolichogenidea xenomorph, a name suggested by the really gruesome life cycle in which its needle-shaped ovipositor is used to inject its eggs into a host and then its larvae devour it from the inside until they burst out of its body, like the xenomorph seen in the movie “Alien” and its sequels.

Wasps are insects belonging to the order Hymenoptera, in which there’s the family Braconidae, which includes parasitoid wasps, which in turn includes the subfamily Microgastrinae down to the genus Dolichogenidea, composed by various species discovered since the beginning of the 20th century. There are 81 genera of Microgastrinae for over 180 species described over the decades.

Erinn Fagan-Jeffries is studying for her Ph.D. at the School of Biological Sciences of the Australian University of Adelaide and under the supervision of Professor Andrew Austin and with the collaboration of Professor Steven Cooper, both of the University’s Australian Center for Evolutionary Biology and Biodiversity, carried out a research on Australian wasps identifying three new species of the genus Dolichogenidea.

The researchers collected over 500 specimens of the subfamily Microgastrinae from all over Australia and determined that there are over 200 species just in that small sample. It’s a remarkable biodiversity and probably many species still have to be identified. The ones described in this research are Dolichogenidea finchi, Dolichogenidea mediocaudata and the most interesting one named Dolichogenidea xenomorph, with its particularly gruesome life cycle.

It’s no coincidence that it was nicknamed Alien-wasp since this small wasp less than 5 millimeters long has a very long needle-like ovipositor it uses to injects its eggs into the body of moth caterpillars. The eggs hatch and the larvae that are born from them start devouring the caterpillars from within until they burst out of their body.

This life cycle is gruesome even for the standards of these parasitoid wasps but various species have a similar one, so much that it’s reported that the xenomorph of the movie “Alien” was created thinking about one of those species. In essence, naming a new species that has also an all-black and shiny body Dolichogenidea xenomorph is a homage but also sort of goes full circle.

These wasps play a role in their ecosystem by controlling the populations of the moths used as hosts. For this reason the cases in which they’re introduced in agricultural areas to eliminate parasite caterpillars that infest crops are common. This is the reason why getting to know new species of parasitoid wasps is not only interesting from a scientific point of view and curious for the homage in the name of the species Dolichogenidea xenomorph but also because it offers new possibilities to replace the use of pesticides.

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