‘Alien’ parasitic wasps lay eggs in caterpillars that burst through them

This is the parasitic wasp Dolichogenidea xenomorph. Credits: Photo by Erinn Fagan-Jeffries

The inspiration for the chestburster creature from “Alien”, a very rare subfamily of parasitoid wasps reproduce by literally placing or injecting its eggs in an unsuspecting caterpillar, which leads to the eggs literally eating their way to freedom.

According to research published in the Journal of hymenoptera Research, three new species of Microgastrinae wasps are called, of which the name Dolichogenidea xenomorph, xenomorph is the name of the creature in the 1979 sci-horror film, “Alien.”

“Dolichogenidea xenomorph acts as a parasite on caterpillars in a similar way that the fictional Alien in its human host,” lead researcher Dr. Erinn Fagan-Jeffries of the University of Adelaide, School of Biological Sciences, said in a statement.


“The wasp is black and shiny as the stranger, and has a number of strange features of the genus — so xenomorph, what ‘strange shape’, fits really well,” Dr. Fagan-Jefferies added.

D. xenomorph is small, only 0.2 inch (5 mm) long, but it sports a pair of black antennas that are more than double the length of the body. Females are equipped with a very long ovipositor which they inject the eggs into the unsuspecting hosts, the researchers noted.

In addition to the D. xenomorph, the researchers describe two others, Dolichogenidea finchi and Dolichogenidea mediocaudata, but it is the D. xenomorph that is understandable, grabbing the most attention.

“This species is named after the fictional creature from the movie franchise ‘Alien’, which was allegedly inspired by the life cycle of the parasitic wasps,” the researchers wrote in their paper. “The name of the fictional creature comes from the Greek ‘xeno’ (strange) and ‘morphe’ (form) that is also appropriate.”

Researchers believe that as many as 10,000 of Microgastrinae wasps on the planet, but only a few thousand have actually been identified, LiveScience reports.

Female D. xenomorph wasps generally lay their eggs in the Australian moth caterpillars known as Antipterna euanthes. The female D. xenomorph adds dozens of small eggs in the caterpillars and, after they hatch, the begin to eat the host body from the inside. Or in the words of actor Tom Skerrit, who played the character Dallas in the film, “like he exploded from inside.”

Once they’ve gorged on their share of the blood, and there is no extra space on the inside of the butterfly caterpillars grow in the larvae chew through the body in the span of a few weeks. From there, they spin a communal cocoon as they embark on their next phase of development, the researchers added.

In the assumption that the caterpillar does not die after the xenomorph larvae burst through, it would be a bodyguard for the newly hatched wasps, LiveScience added. Eventually, the caterpillar does die (bad zombie caterpillar) and then the cycle repeats, with the newly-formed xenomorphs in search of other hosts.


It is unclear exactly how widespread the species is (so far, they’ve only found in southeastern and southwestern coasts of Australia, according to the researchers), but the cruelty is undisputed.

“Less than 5 mm in length, Dolichogenidea xenomorph seems to be lacking the punch of its fearsome namesake,” Fagan-Jeffries said. “But the size is relative; a host caterpillar, it is a great predator.”

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