Adult B. hungerfordi have a yellowish brown coloring with irregular dark markings and narrow stripes of fine closely spaced darkish pigmented perforations on their wing covers. Brychius hungerfordi can be distinguished by the distinct shape of its pronotum, the dorsal plate between the head and base of the wings. Adults are generally 0.15-0.17 inches (3.70-4.35 mm) long and 0.07-0.09 inches (1.90-2.25 mm) wide with females tending to be larger than males. Males can also be differentiated from females by their front legs. On males, the first three segments have small tufts of hair. Tarsal segments are also thickened.
Brychius hungerfordi larvae have a stiff, light yellowish brown body with a cylindrical shape that tapers into a hooked tail. Larvae also have short legs with single tarsal hooks (Spangler, 1954; Hyde and Smar, 2000).
Brychius hungerfordi is located in isolated locations in Michigan's northern Lower Peninsula in the Cheboygan River watershed and Ontario's Bruce Peninsula in the North Saugeen River (Hyde and Smar, 2000).
Brychius hungerfordi lives in cool (15 to 25 deg C), clean, well-aerated, slightly alkaline streams with open to partially open canopy. Flows where B. hungerfordi are found are moderate to fast (Hyde and Smar, 2000;U.S.F.W.S. 1994).
Hinz and Wiley (1999) characterized known locations of B. hungerfordi by using the Michigan Valley Segment Ecological Classification System (MI-VSEC) (Seelbach et al 1997). The beetle was found in rivers with hardwater oligotrophic (low in nutrients) chemistries. Base flows in localities where B. hungerfordi was found were fair, and peak flows were low to moderate. Water temperatures were characterized as cold to cool July temperatures with moderate daily temperature fluctuations. Valley slope was low.
Adults and larvae occupy different microhabitats. Adults are usually found on gravel and stones in fast moving currents and well-aerated riffles. Larvae were observed in the slower currents of the stream where Chara or other macroalgae are dense (Hyde and Smar, 2000; U.S.F.W.S. 1994).
In the spring and early summer months, B. hungerfordi probably lays eggs on filamentous algae and aquatic plants. The larvae are believed to go through three instars before finally pupating to adults. Although the time between oviposition and final emergence of the adult depends on temperature, it generally takes about seven weeks (Hyde and Smar, 2000; U.S.F.W.S. 1994). Larvae may overwinter.
Fish, tadpoles and other aquatic insects prey on adult B. hungerfordi. They are most vulnerable to these predators when they must swim to the water surface for air. Otherwise, B. hungerfordi avoids predators by hiding among plants and filamentous algae and by preferring habitats in shallow swiftly flowing water which places them out of harms way of mid-water and benthic predators (Hyde and Smar, 2000).
Adults were observed to be strong swimmers, unlike other insects in their family. Aquatic insects usually disperse downstream as larvae and fly upstream as adults. However, B. hungerfordi shows little downstream dispersion and adults seem reluctant to fly. Adults may move upstream by swimming (Hyde and Smar, 2000).
Both adult and larval B. hungerfordi are herbivorous, probably feeding on algae and periphyton by scraping gravel and stones with their mandibles (Hyde and Smar, 2000; U.S.FWS, 1994).
Logging, beaver control management, pollution and other human stream modifications have likely contributed to the reduction of B. hungerfordi habitat (U.S.F.W.S. 1994). Introduction of sport fish which may prey on B. hungerfordi may have also contributed to its decline (Hyde and Smar, 2000). This species is listed as endangered by the U.S. Fish and Wildlife Service and by the state of Michigan.
Brychius hungerfordi was only recently discovered in 1952 by P.J. Spangler. Very little is still known about this species (Hyde and Smar, 2000).
Seann Clifford (author), University of California, Irvine, Rudi Berkelhamer (editor), University of California, Irvine.
Hinz, L., M. Wiley. 1999. Prediction of the distribution of *Brychius hungerfordi* Spangler in Lower Michgan Streams. Report to the Michigan Natural Heritage Program, Michigan Department of Natural Resources. 19 pp..
Hyde, D., M. Smar. 2000. "Special animal abstract for *Brychius hungerfordi* (Hungerford's crawling water beetle). Michigan Natural Features Inventory, MI. 4 pp." (On-line). Accessed February 20, 2003 at http://www.msue.msu.edu/mnfi/abstracts/zoology/brychius_hungerfordi.pdf.
Michigan Department of Natural Resources, "Hungerford's Crawling Water Beetle (*Brychius hungerfordi*)" (On-line). Accessed February 20, 2003 at http://www.michigan.gov/dnr/1,1607,7-153-10370_12145_12204-33001--CI,00.html.
Seelbach, P., M. Wiley, J. Kotanchik, M. Baker. 1997. "A landscape-based ecological classification system for river valley segments in lower Michigan (MI-VSEC version 1.0). Michigan Department of Natural Resrouces, Fisheries Research Report 2036, Ann Arbor." (On-line). Accessed (Date Unknown) at http://www.michigandnr.com/PUBLICATIONS/PDFS/ifr/ifrlibra/Research/reports/2036rr.pdf.
Spangler, P. 1954. A New Species of Water Beetle from Michigan (Coleoptera: Haliplidae). Entom. News, 65: 113-17.
U.S. Fish & Wildlife Service, 1994. "Determination of Endangered Status for Hungerford's Crawling Water Beetle" (On-line). Accessed Feb. 15, 2001 at http://endangered.fws.gov/r/fr94533.html.