 |
| Syntretus perlmani Shaw & Ballinger, in Moore, Amuwa, Shaw et Ballinger, 2024. |
Abstract
Parasitoid wasps are exceptionally diverse and use specialized adaptations capable of manipulating the physiology and behaviour of host organisms. In more than two centuries since the first records of Drosophila-parasitizing wasps, nearly 200 described and provisional parasitoid species of drosophilids have been identified. These include endoparasitoids and ectoparasitoids, as well as species attacking larval and pupal hosts. Despite a deep history of research attention and remarkable biodiversity, a wasp species that attacks and develops inside the adult stage of a fly host has not been described previously. Here we report the discovery of a wasp species that infects the adult stage of fruit flies in the genus Drosophila, including one of the most deeply studied model organisms in biology, Drosophila melanogaster. Notably, this wasp can be easily collected from backyard fly baits and has a broad geographic distribution throughout the eastern USA. We document its life history and unique host interactions, including egg-laying into and larval emergence from adult flies, and provide protocols to raise wasps from wild-caught host flies. Our results emphasize the need for ongoing research investment in insect biodiversity and systematics. As parasitoid research continues to uncover unusual biology and supports fundamental mechanistic insights into immunity, metabolism, ecology, evolution and behaviour, we anticipate that this wasp’s association with the laboratory model organism, D. melanogaster, will provide new research opportunities across the life sciences.
 |
| a, The life cycle of S. perlmani, including oviposition (1), early larval development (2), appearance of teratocytes (2′), late larval development and reduction in teratocyte number (3), larval emergence (4), cocoon formation and metamorphosis (5) and adult emergence (6). |
 |
| a,b, The development of wasp larvae inside host flies (a) is accompanied by growth of wasp teratocytes (b, black arrows), which can be seen through the host abdominal cuticle and obstruct the view of the testes (b, white arrow). c, The second and following larval instars lack a head capsule and tail spike, and the final instar grows to nearly the length of the host fly (see Supplementary Video 2). d, Pupal development takes place within a white silken cocoon as is typical of euphorine wasps. e, Larval emergence is always from the abdomen and has been observed to occur between the second and third tergites (dorsolaterally) or laterally through a tear in the abdominal cuticle. f, The adult wasp (male shown) is small, yellowish brown and approximately 1.5 mm in length. Scale bars, 0.5 mm (a–d) and 1 mm (e,f). |
 |
| Syntretus perlmani sp. nov. a, Holotype lateral habitus. b, Holotype propodeum. c, Holotype forewing venation. Scale bars, 1 mm (a), 100 μm (b) and 400 μm (c). |
Family Braconidae Latrielle, 1829
Subfamily Euphorinae Foerster, 1862
Tribe Syntretini Shaw, 1985
Genus Syntretus Foerster, 1862
Subgenus Syntretus Foerster, 1862
Syntretus perlmani sp. nov. Shaw & Ballinger, 2024
Differential diagnosis. Syntretus perlmani sp. nov is a tiny species that is distinct from other known Syntretus species by virtue of its small size (body length about 1.5 mm) and utilization of adult Drosophila flies as hosts. The antenna is shorter than the head and mesosoma combined, and there are 12–13 flagellomeres. Often the antenna has only 12 flagellomeres (the lowest number recorded for any North American Syntretus species).
Of the North American species, S. perlmani is most similar to Syntretus brevicornis Muesebeck, which also has a small body size and short antenna. Of the two species, S. perlmani is the smaller, with a body length of about 1.5 mm, as compared to 2.2 mm for ...
Etymology. This species is named after Steve Perlman (University of Victoria, British Columbia, Canada), in recognition of his contributions to research and mentorship in the field of Drosophila–parasite interactions.
Logan D. Moore, Toluwanimi Chris Amuwa, Scott Richard Shaw and Matthew J. Ballinger. 2024. Drosophila are hosts to the First described parasitoid Wasp of Adult Flies. Nature. 633; 840–847. DOI: doi.org/10.1038/s41586-024-07919-7
reflector-online.com/30665/news/new-species-of-parasitoid-wasp-discovered-in-starkville
