Thoracophorus brevicristatus (Horn, 1871)

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 : 4

Thoracophorus brevicristatus (Horn, 1871) ( Figs. 2 , 6 )

Range. UNITED STATES: Arizona, Florida ,

Louisiana, Texas. MEXICO. WEST INDIES.

COSTA RICA. MASCARENE ISLANDS. PHILIPPINES (Herman 2001; Navarrete-Heredia et al. 2002). Blackwelder (1943) had “grave doubts” that T. brevicristatus var. deletus Fauvel (1902) from the Mascarene Islands and Philippines was truly a variety of T. brevicristatus . In that case, those ranges are in error. Thoracophorus brevicristatus is probably also present in southern Alabama, Georgia, and Mississippi, based on extrapolation from documented occurrences.

Collection Methods. Hand collection, Berlese funnel, floating pitfall trap, elevated flight intercept trap, Lindgren funnel trap.

Habitat. Floating aquatic vegetation, forest litter, cottonwood duff, rotten log, dense costal brush, under bark of dead cottonwood, under bark of dead sugarberry, Celtis laevigata Willd. (Cannabaceae) , dead sotol, Neotoma Say and Ord [packrat] nest, Trametes corrugata (Pers.) Bres. [polypore fungus], cedar-elm forest.

Comments. In total, 38 specimens of T. brevicristatus were examined from 13 counties (or equivalents) within four states in the United States. Specimens were collected during March through December, and adults are probably available year-round throughout their range. Based on this study, no clear distinction between preferred habitat of T. brevicristatus and T. costalis can be identified, and why T. brevicristatus is so rarely collected is unclear. Irmler (2010) reported that T. brevicristatus is an inquiline of Neotermes Holmgren termites ( Isoptera : Kalotermitidae ) based on observations by Boháč (1978). While Boháč (1978) observed adults and immatures living in a termite colony, he provided little evidence that T. brevicristatus were more than tolerated by their hosts. Information from specimens collected in the United States indicate that T. brevicristatus may be found in a wide variety of situations and its association with termites, at least in the United States, is unclear.

Collection localities of T. brevicristatus in Arizona may represent a narrow northern population extension from Mexico ( Fig. 8 ). The next nearest locality in the USA is 1,300 km east. In eastern Arizona , the synoptic insect collection at the Southwestern Research Station in the Chiricahua Mountains ( Fig. 8 , #6) does not possess specimens of T. brevicristatus . No specimens have been collected in or around that area by Louisiana State Arthropod Museum members despite extensive collecting (30,000+ specimens) during the past five years. The northern limit of the species may be south of extreme eastern Arizona, New Mexico , and western Texas.

References. Horn 1871 (as Glyptoma brevicristatus , figures and key separating T. costalis from T. brevicristatus ); Blackwelder 1943 (key separating T. brevicristatus from T. guadalupensis ); Newton 1984 (fungivory); Irmler 1985 (key to species, illustrations of head, pronotum, and aedeagus, in German), 2010 (general ecology of the genus); Burakowski and Newton 1992; Herman 2001; Navarrete-Heredia et al. 2002.

Figures

Fig. 2. Distribution of Thoracophorus brevicristatus in the United States by county.

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

Fig. 8. Map of the southeastern corner of Arizona, with collection localities of Thoracophorus brevicristatus. 1–4: approximate collection locations of specimens examined in this research; 5: approximate type locality; 6: Chiricahua Mountains and surrounding areas where no specimens of T. brevicristatus have been obtained despite intense collecting.