Gondwanocrypticus platensis (Fairmaire, 1883)

Steiner Jr., Warren E. & Swearingen, Jil M., 2015, New Records of Three Non-Native Darkling Beetles (Coleoptera: Tenebrionidae) Established in California and Nevada, USA, The Coleopterists Bulletin (mo 14) 69, pp. 22-26 : 23-24

Gondwanocrypticus platensis (Fairmaire, 1883)

Mention or listing of this South American species as occurring in California ( Steiner 2010; Aalbu and Smith 2014; Steiner and Swearingen 2014) is substantiated below with specimen label data. Images have also been posted on Bugguide (2015b) with the following information: “Palm Springs, Riverside County, California, USA, June 26, 2012 ” (photograph by Stephen Luk ); “Long Beach, Los Angeles County, California, USA, April 8, 2014 ” [and January 27, 2012] (photograph by Kim Moore ); “University Community Park, Irvine, Orange County, California, USA, May 18, 2013 ” (photograph by Ron Hemberger); “Webb Canyon, ∼ 2000 ft. elevation, Los Angeles County, California, USA, March 18, 2009 ” and “ April 7, 2010 ” (photograph by Harsi S. Parker) .

Specimens Examined. “ C A L I F O R N I A: Alameda Co., Livermore, 37°40′54″N, 121°46′ 07″W, 11 October 2009, coll. W. E. Steiner & J. M. Swearingen” (4, + associated ant Tetramorium sp. possibly caldarium (Roger)); “ Fresno Co., Fresno, near airport, 36°46′22″N, 119°44′12″W, 18 October 2009, coll. W. E. Steiner & J. M. Swearingen” (1); “ Kings Co., 7 km N Avenal, 36°04′02″N, 120°06′21″W, 12 October 2010, coll. W. E. Steiner & J. M. Swearingen / Under stones and leaf litter, roadside turf on sandy clay soil” (1, + associated ants Solenopsis xyloni McCook ); “ Merced Co., Merced, 37°18′12″N, 120°29′54″W, 11 October 2009, coll. W. E. Steiner & J. M. Swearingen” (7, + associated ants Linepithema humile (Mayr)) ; “ Orange Co., Newport Beach, 33°38′24″N, 117°52′32″W, 16 December 2010 / W. E. Steiner, J. M. Swearingen, N. J. Vandenberg, M. A. Brown, collectors” (1); same data except “Back Bay, 33°38′02″N, 117°53′06″W, under matted dead grass at roadside, sandy soil” (1 seen but not captured); “ Riverside County, Palm Desert, 33°43′15″N, 116°21′45″W, 9 June 2010 / Under grass thatch and leaf litter, open edge of sandy turf; coll. W. E. Steiner & J. M. Swearingen” (12, + associated ants S. xyloni ); “ CALIFORNIA: San Mateo Co., San Bruno, Forest Lane Park, 37° 37′58″N, 122°25′05″W, 22 October 2010 / Under matted grass thatch on sandy soil, edge of open turf; colls. W. E. Steiner & J. M. Swearingen” (10, + associated ants L. humile ); “ Stanislaus County, 2 km SE. Turlock, 37°27′58″N, 120°49′ 37″W, 11 October 2009 / W. E. Steiner & J. M. Swearingen collectors” (1, + associated ants Tetramorium sp. possibly caldarium, Solenopsis probably aurea Wheeler); “ San Diego County; Fashion Valley, 32°45′56″N, 117°10′03″W, 12 December 2007 / W. E. Steiner & J. M. Swearingen collectors” (12, + associated ants L. humile ); same data except “ 12 December 2010 ” (3, + associated ants L. humile ).

Our 2007 collection of G. platensis in San Diego County is the earliest known record for the state; it has evidently spread rapidly northward to the San Francisco Bay area. We have searched suitable habitats in the Napa Valley and north to Chico during 2009–2014 without detecting the beetle, but its further spread to these areas is anticipated. Whether the beetle arrived in California via Mexico or was introduced from the southeastern US (e.g., transported in potted plants) is curious speculation. Earliest US specimen records indicate spread from Mobile, Alabama after 1929 across the southeastern states from Delaware to Texas (Steiner and Swearingen 2014), where it can be very abundant and often associated with debris around ant nests. It is thought to have been introduced to this region in association with imported fire ants ( Solenopsis Westwood ). This “weed species” has also reached the Bahamas (Steiner 2011) and Cayman Islands (Thomas et al. 2013). California collections with associated ants have involved primarily non-native ant species. The Argentine ant, L. humile , was also associated with Opatroides punctulatus Brullé in the Sacramento area (Aalbu et al. 2009).