| Scientific Name | Specimen Records |  Click photo to enlarge. Photo by Charles Staines. |
|||
| Acilius fraternus (Harris) | ATBI Database | ||||
| Common Name | |||||
| N/A | |||||
| Kingdom | Phylum | Class | Order | Family | |
| Animalia | Arthropoda | Insecta | Coleoptera | Dytiscidae | |
| Animals | Arthropods | Insects | Beetles | Predaceous Diving Beetles | |
Physical characteristics:
Adult: Body broadly oval, widest on apical fourth. Head reddish with diffuse black markings, lacking the distinct M-shaped spot of A. mediatus. Pronotum lighter with two black bands. Elytra dark, pale spot near apex of elytra outlined in solid black and lateral margin yellowish. Venter dark, abdominal sterna 1 and 2 entirely black. Elytral punctures dense, more or less rounded. Males with tufts of hairs on the inner margins of the first three tarsal segments. Females without four ridges on elytra. (Bergsten & Miller 2006)
Adult body length: 13-16 mm.
Larvae: Elongate, tapering anteriorly and posteriorly from widest point; convex dorsally, flattened ventrally; color brownish to yellowish-brown with vague darker markings. Head with six ocelli. Antennae 6-segmented, about ½ length of head. Pronotum glabrous, longer than wide. Abdomen 8-segmented, segments 2 and 3 widest, segments 1-6 sclerotized dorsally, 7 and 8 entirely sclerotized. Legs 5-segmented; femora longest segment. (Wolfe 1980)
Larval body length: 30 mm.
Distribution:
Global
This species is known from Massachusetts to Florida and west to Texas, Kansas, and Iowa (Bergsten & Miller 2006).
Park
This species is known only from the Cades Cove area of the park. Specimens have been collected in temporary pools and ponds from May to July.
Natural History:
Habitat
This species is most often collected in shaded ponds and pools with some leaf litter and no vegetation. It is also found in lakes, ditches, streams, and swamps. Adults are taken at lights. (Michael & Matta 1977; Larson et al. 2000; Ciegler 2003; Bergsten & Miller 2006)
Conservation Biology
The species is common, widespread, and not globally threatened.
Acknowledgements
Text:
Charles Staines.
Photographs:Charles Staines.
Web page:
References
Bergsten, J. & K. B. Miller. 2006. Taxonomic revision of the Holarctic diving beetle genus Acilius Leach (Coleoptera: Dytiscidae). Systematic Entomology 31:145-197.
Ciegler, J. C. 2003. Water beetles of South Carolina (Coleoptera: Gyrinidae, Haliplidae, Noteridae, Dytiscidae, Hydrophilidae, Hydraenidae, Scirtidae, Elmidae, Dryopidae, Limnichidae, Heteroceridae, Psephenidae, Ptilodactylidae, and Chelonariidae). Biota of South Carolina. Volume 3. Clemson University, Clemson. 207 pp.
Larson, D. J. Y. Alarie, & R. E. Roughley. 2000. Predacious diving beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with emphasis on the fauna of Canada and Alaska. NRC Press. Ottawa. 982 pp.
Michael, A. G. & J. F. Matta. 1977. The Dytiscidae of Virginia (Coleoptera: Adephaga) (Subfamilies: Laccophilinae, Colymbetinae, Dytiscinae, Hydaticinae, and Cybistrinae). Virginia Polytechnic Institute and State University, Research Bulletin 124. 53 pp.
Wolfe, G. W. 1980. The larva and pupa of Acilius fraternus fraternus (Coleoptera: Dytiscidae) from the Great Smoky Mountains, Tennessee. Coleopterists Bulletin 34(1):121-126.
