New Parasitic Wasp Species Discovered in Eastern US

Syntretus perlmani infects the adult stage of fruit flies in the genus Drosophila, including one of the most deeply studied model organisms in biology, Drosophila melanogaster.

Evolutionary conflict between parasites and their hosts is a driving force behind some of the most specialized adaptations observed across the tree of life.

Among the insects, such adaptations are used by the parasitoid wasps, which lay their eggs and develop in or on a live host.

The newly-described species of parasitoid wasp infects the adult stage of several divergent host species in the genus Drosophila, including Drosophila affinis and Drosophila melanogaster.

Named Syntretus perlmani, this wasp is distinct from other species in the genus Syntretus by virtue of its small size (body length about 1.5 mm).

It can be easily collected from backyard fly baits and has a broad geographic distribution throughout the Eastern U.S.

“Syntretus perlmani is a spectacular example of undescribed biology hidden in plain sight across a species that attacks the adult stage, until now,” said Dr. Matthew Ballinger, a researcher at Mississippi State University.

“All known parasitoid wasps of flies attack and develop inside immature life stages, and despite 200 years of research on parasitoid wasps of Drosophila and other flies, we have never come.”

The researchers began the project by collecting infected fruit flies from his backyard in Starkville, Mississippi.

They then used a combination of field collections and public data to show the new species lives across the Eastern U.S.

“Studying how parasites and pathogens influence Drosophila biology and behavior has helped researchers learn more about fundamental biological processes like immunity and reproduction,” Dr. Ballinger said.

The scientists also documented the wasp’s complete life cycle and provided instructions for others to raise adult wasps in the laboratory.

“We’re excited to learn more about the new species, and we hope other researchers will begin their own projects to better understand its infection biology, ecology and evolution in the coming years,” Dr. Ballinger said.

The discovery is reported in a paper in the journal Nature.

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L.D. Moore et al. Drosophila are hosts to the first described parasitoid wasp of adult flies. Nature, published online September 1, 2024; doi: 10.1038/s41586-024-07919-7