New ‘horror’ wasp species hatches inside fruit flies, bursts out and kills them

In a horrifying and fascinating act of nature, a researcher from Mississippi State University discovered a new parasitic wasp in his backyard that hatches inside adult fruit flies. Worthy of a sci-fi horror flick, when the baby wasp bursts from their abdomen, the host evidently dies.

As stated in their study published in Nature, there’s nothing new about parasitoid wasps. In fact, over 200 have been described. However, “all known parasitoid wasps of flies attack and develop inside immature life stages,” lead author Matthew Ballinger told Mississippi University. This new species, Syntretus perlmani, attacks adult flies, so it diverges from the classic behavior exhibited by this group.

“Our results emphasize the need for ongoing research investment in insect biodiversity and systematics,” study authors write, to understand the mechanisms of nature more profoundly.

The killer wasp bursts forth from the abdomen of adult flies

In a classic story, “You never know what you’ll find in your own backyard,” Logan Moore, a Ph.D student, was collecting Drosophila affinis fruit flies in his yard. He unexpectedly found an S. perlmani in the abdomen of a male D. affinis.

Once identified as a “euphorine braconid wasp,” according to the study, known an “unusual strategy of ovipositing and developing within adult insects,” he understood he stumbled upon a new species with this genus.

Described as a “spectacular example of undescribed biology hidden in plain sight,” the species was easily extracted from backyards across the Eastern US inside the Drosophila melanogaster fruit fly, one of the most studied animals in biolog y because 60% of the fly’s genes are found in humans and 75% of those are known to cause diseases in humans.

Drosophila possesses more than 90 percent of the genes that can trigger cancer in humans, even, so scientists use the fruit fly to study the genetic function of disease in humans.

Now, scientists have a new reason to study the fruit fly: It might be housing an S. perlmani wasp .

A sickening strategy in nature might teach us something about it

In the lab, they collected and screened over 6,000 D. affinis from Mississippi, Alabama, and North Carolina as per the study and confirmed the gestation period of the new wasp lasted between seven to eighteen days, “at which point the wasp larva and teratocytes grow large enough to swell the abdomen and obstruct the view of the host’s brightly pigmented testes.”

“It will effectively emerge out of the side of the fly,” Moore told Live Science . “And just to add an additional layer of horror, the fruit fly will normally remain alive for several hours after that.” Then, they buried themselves in a substrate and cocooned for about 23 days to emerge as adults . Their DNA also contained “mashed-up Drosophila melanogaster,” so they spawn from infection.

Such an insect might make one squirm, but “studying how parasites and pathogens influence Drosophila biology and behavior has helped researchers learn more about fundamental biological processes like immunity and reproduction,” Ballinger said, the university’s official statement concludes.