Synuchus impunctatus (Say, 1823)

Hatten, Timothy D., Merz, Norm & Looney, Chris, 2011, Synuchus impunctatus (Say) (Coleoptera: Carabidae) in Idaho, U. S. A.: New State Record, The Coleopterists Bulletin 65 (3), pp. 325-326 : 325

SYNUCHUS IMPUNCTATUS (SAY) ( COLEOPTERA : CARABIDAE ) IN IDAHO, U.S.A.: NEW STATE RECORD

TIMOTHY D. HATTEN Invertebrate Ecology Inc., 121 W. Sweet Ave , Moscow, ID 83843, U.S.A. [e-mail]

NORM MERZ Fish and Wildlife Department, PO Box 1269, Kootenai Tribe of Idaho Bonners Ferry, ID 83805, U.S.A.

AND

CHRIS LOONEY Exotic Pest Survey, Washington State Department of Agriculture Box 42560, Olympia, WA 98504-2560, U.S.A.

Synuchus impunctatus (Say, 1823) is one of three species of Synuchus Gyllenhal native to North America. This eurytopic beetle occurs in a variety of habitats including light forest, vacant lots, and cultivated fields, and ranges from lowlands to montane communities (Larochelle and Larivière 2003). The species is primarily nocturnal, sheltering during the day among leaves, downed wood, moss, and other litter. Most individuals are brachypterous, although macropterous individuals have been taken at lights (Lindroth 1966). Adults tend to bury themselves in leaf litter when alarmed, and exhibit omnivory typical of some platynine ground beetles (Larochelle and Larivière 2003).

The known distribution of S. impunctatus is primarily eastern and midwestern USA ( Casey 1924; Bousquet and Larochelle 1993), with a few collections from northwestern Washington ( Hatch 1953). In Canada, the species is transcontinental (Lindroth 1966; Bousquet and Larochelle 1993). Here we present data for a specimen of S. impunctatus collected in Idaho, extending the known range and adding a new state record.

We collected one specimen of S. impunctatus in a non-baited pitfall trap during 2008 as part of a broad, interdisciplinary study examining the influence of river regulation (e.g., Libby Dam) on the flora and fauna of the Kootenai River floodplain. The trap was situated in a broadleaf riparian forest dominated by mature cottonwood trees ( Populus spp. ) with an understory of scattered shrubs ( Cornus sericea L., Sambucus sp. , Symphoricarpos albus [L.] S. F. Blake) and reed canary grass ( Phalaris arundinacea L.). The specimen was of brachypterous phenotype and was collected along with two specimens of Pterostichus melanarius Illiger and one specimen of Bembidion incrematum LeConte. It is deposited in the William F. Barr Entomology Museum at the University of Idaho. Specific collection data are: Site 7-207, elevation 544.5 m, latitude 48°43 ′ 35.0 ″, longitude -116°24 ′ 47.4 ″, 23, July 2008, R. Capilo and T. Gossen collectors. The site is located on the Kootenai National Wildlife Refuge in Boundary Co., ID approximately 7 km west of Bonners Ferry, ID and approximately 31 km south of Canada. Situated on the west side of the Meander Reach of the Kootenai River, the refuge encompasses a variety of wetland habitats (e.g., tree-lined ponds and creeks, water ponds, seasonal cattailbullrush marshes) which are managed primarily for migrating waterfowl. Upland habitats on the reserve include agricultural fields, meadows, dry grasslands, and mixed-conifer forests. Such diversity of habitats likely benefits the eurytopic S. impunctatus and other carabid species as well (Hatten et al. 2009).