Thoracophorus costalis (Erichson, 1840)

Ferro, Michael L., 2015, Review Of The Genus Thoracophorus (Coleoptera: Staphylinidae: Osoriinae) In North America North Of Mexico, With A Key To Species, The Coleopterists Bulletin 69 (1), pp. 1-10 : 5-7

Thoracophorus costalis (Erichson, 1840) furrowed rove beetle ( Figs. 1 , 4–5 )

Range. CANADA: Alberta, Manitoba, Ontario, Québec. UNITED STATES: Alabama, Arkansas, Colorado, Connecticut, District of Columbia, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, New Hampshire, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin. MEXICO (Irmler 1985; Herman 2001; Navarrete-Heredia et al. 2002) .

Collection Methods. Hand collection, pitfall trap, emergence chamber, Berlese funnel, fogging, UV light, flight intercept trap, Malaise trap, canopy trap, x-vane trap, ethanol-baited Lindgren funnel, cantharidin-baited Lindgren, alpha pinene-baited Lindgren funnel.

Habitat. Top soil in deep woods, forest litter, leaf litter, leaf mould, ground cover, ground cover edge of woods, litter under shrubs in draw, litter at base of rock bluff, litter under Populus stand, magnolia leaf litter, sawdust, slab pile, base of fungusy tree bole, rotten stump, standing barkless Ulmus sp. bole in woods, maple stump, oak stump litter and passalid beetle frass, debris under rotten Populus stump, old maple log, funguscovered logs, slime mold covered log, rotten Quercus log, sifted hollow log, fogging fungusy cut logs, under rotten log, dead tulip tree, under bark, under bark dead Pinus taeda , under deciduous bark, ex. hackberry bark, under pine bark, bark of dead pine, bark of bleeding Ostrya , tree hole, Populus tree hole debris, reared from elm, ex. Myxomycetes, misc. mushrooms, gilled mushroom, ex. Polyporus sp. , white crustose polypore, mouse nest in stump, Neotoma nest, nest of Lasius niger americanus - under bark encircling old stump, roof and floor of beaver lodge.

Comments. In total, 4,926 specimens of T. costalis were examined from 464 counties (or equivalents) within 41 states (or equivalents) in the United States and Canada ( Fig. 1 ). Specimens were collected during each month, and adults are probably available year-round throughout their range. Based on the known range and the wide variety of collection habitats, T. costalis is probably present in every US county and county equivalent along the southern border of Canada located east of 95° longitude. The few county records from Iowa, Maine, Minnesota, New York, Pennsylvania, and West Virginia are probably due to poor collecting rather than true gaps in distribution. No specimens were seen from Rhode Island, but T. costalis has been reported from that state (Sikes 2004).

The western records of the species were unexpected, especially records from Montana and Edmonton, Alberta, Canada. Additional collecting in the extreme western range is needed to resolve if the species is truly rare, restricted to a narrower “habitat”, or just overlooked by collectors. Thoracophorus costalis is probably also present in North Dakota, Wyoming, and Saskatchewan. Fauvel (1878) reported T. costalis from California, however, no specimens from California could be found, so this may be an error.

On a wider scale, T. costalis may not be restricted to North America north of Mexico. Irmler (1985) reported T. costalis from Mexico, but Navarrete- Heredia et al. (2002) were unable to confirm the record. However, a specimen of T. costalis (identification determined by U. Irmler and checked by myself) is in the MCZ collection with the label reading in full: “Mex.” More specimens are needed before the southern extent of the species’ range can be confirmed. Additionally, T. costalis has been collected from southern Florida and may extend into the northern Caribbean Basin.

Despite being widespread and well-represented in collections, little is known about T. costalis beyond collection data. Graves (1960) sampled organisms inhabiting a wide variety of woody shelf fungi and collected many T. costalis from Ganoderma applanatum (Pers.) Pat. (as Fomes applanatus ?). He reported that T. costalis would burrow through the conk and directly eat the fungi. In some instances, adults could be found in large numbers, and immatures and copulation were also observed within the conk. Ferro et al. (2012b) found that T. costalis had significantly higher abundance in later decay stages of coarse woody debris than earlier stages. Thoracophorus costalis also had significantly higher abundance in decay class V coarse woody debris than leaf litter (Ferro et al. 2012a).

References. Horn 1871 (as Glyptoma costale Erichson , figures and key separating T. costalis from T. brevicristatus ); Blatchley 1910 (as G. costale ); Notman 1920; Newton 1984 (fungivory), 1990 (generic key of immature Staphylinidae ); Irmler 1985 (key to species, illustrations of head, pronotum, and aedeagus, in German), 2010 (ecology); Burakowski and Newton 1992; Downie and Arnett 1996 (figure is not T. costalis ); Peck and Thomas 1998; Herman 2001; Navarrete-Heredia et al. 2002; Ferro and Gimmel 2011.

Figures

Fig. 1. Distribution of Thoracophorus costalis in the United States and Canada by county (or equivalent).

Figs. 4–7. Thoracophorus species, habitus. 4) T. costalis, teneral, contracted specimen; 5) T. costalis, mature, extended specimen; 6) T. brevicristatus; 7) T. guadalupensis.