Nicrophorus americanus Olivier, 1790

Mullins, Patricia L., Riley, Edward G. & Oswald, John D., 2013, Identification, distribution, and adult phenology of the carrion beetles (Coleoptera: Silphidae) of Texas, Zootaxa 3666 (2), pp. 221-251 : 230-232

Nicrophorus americanus Olivier, 1790

Figs. 10, 11 , 24 , 37 , 50

Nicrophorus americanus Olivier, 1790: 6 (see Sikes et al. (2002) for synonymy).

Diagnosis. Body length 25–35 mm; black with frons and pronotal disc red-orange; elytron with anterior and posterior transverse maculae red-orange; entire epipleuron red-orange, anteriorly glabrous; anterior and posterior elytral maculae not joined laterally; anterior elytral macula transverse joining epipleuron, not reaching elytral suture, not extended forward below humerus; posterior elytral macula transverse, not joined to epipleuron, not reaching suture. Antennal club entirely orange. Pronotum orbicular with transverse anterior impression, disc glabrous, lateral margins broad. Dorsal surface of elytron without long hairs. Epipleural ridge extended to point below or almost below humeral callus. Lateral portion of metasternum densely covered with golden hairs. Posterior lobe of metepimeron glabrous or nearly so. Tarsal empodium quadrisetose.

Range. Nicrophorus americanus was listed in 1989 as an endangered species by the U.S. Fish and Wildlife Service (Lamson 1989). Its historical range encompassed 35 states, the District of Columbia, and three eastern Canadian provinces (Backlund et al. 2008, Amaral et al. 2008). The beetle now exists in less than 10% of its original range (Sikes & Raithel 2002). Localities with apparent extant populations are restricted to the western fringe of its original range (eastern Oklahoma, western Arkansas, southeastern Kansas, central and southern Nebraska, south-central South Dakota, and northeastern Texas) and Block Island, Rhode Island (Sikes & Raithel 2002, Godwin & Minich 2005, Raithel & Gingberg 2006, and Amaral et al. 2008).

Texas distribution. See Fig. 50 . Peck and Kaulbars (1987) in their study of the distributions of Nearctic Silphidae did not record N. americanus from Texas. This species has been recorded from Lamar and Red River counties in northeastern Texas. This area is part of the Texan biotic province and the post oak savannah vegetational area. Nicrophorus americanus populations remain present in Lamar County (Godwin & Minich 2005), though recent attempts to re-confirm the presence of the species in Red River County were unsuccessful (Amaral et al. 2008). There are four specimens in the Philadelphia Academy of Natural Sciences collection labeled “Wichita R. Texas J. Both 1880” (J. D. Weintraub, personal communication, 2012), and this is evidence that the historical distribution of this species in northern Texas was once greater than what is observed today. The confluence of the Wichita and Red Rivers (at 98° longitude, in present-day Clay County) is approximately 240 km west of the Lamar County population. This locality is on the border between the Kansan and Texan Biotic Provinces and on the border between the cross timbers-prairies and rolling plains vegetational areas. The collector of the Wichita River series is stated as “J. Both” on the machine-printed specimen labels; however, this is probably a transcription error for Jacob Boll, a general naturalist, entomologist, and collector of natural history specimens from that region and time period. For more than six months, beginning after the middle of December 1879, Jacob Boll explored the Wichita River and all its tributaries for more than 100 miles (Boll 1880). Where in the Wichita River drainage the N. americanus specimens originated is not known since the extent of Boll’s trip covered several present-day Texas counties.

A record of Nicrophorus americanus from the coastal bend region of Texas was mapped by Raithel (1991), Ratcliffe (1996), and Sikes and Raithel (2002). This record is apparently based on a single specimen in the Cornell University Insect Collection, labeled “Kingsville, Tex., C.T. Reed Coll., Cornell Univ., Lot 912 Sub / Nicrophorus americanus, Det. R.H. Arnett, Jr. 1941 / Nicrophorus americanus Ol., det. R. Madge.” (M.A. Quinn, personal communication, 22 September 2009). This disjunct record seems questionable. If the original range of this species extended from northeastern Texas south to the coastal bend, it seems plausible that early beetle collectors in Texas who either lived or travelled through these areas in the late 1800s and early 1900s (E.A. Schwarz, H.S. Barber, J.D. Mitchell) would likely have encountered and saved specimens of this large conspicuous beetle. Horace Burke, Professor Emeritus and entomological historian (Department of Entomology, Texas A&M University) states the following regarding C.T. Reed, supposed collector of the Kingsville specimen: “ … incessant traveler and collector, Theodore Reed (1891–1985), either attended, taught or administered at universities in Kansas, Maryland, New York, Iowa, Pennsylvania, Istanbul ( Turkey!), Texas, (Fort Worth, Corpus Christi, and Kingsville), Tennessee, Arkansas, and Florida from 1910 to 1944.” (Horace R. Burke, personal communication, 2004).

Our Texas occurrence records for this species were taken from one examined Texas specimen (SFAC), images of specimens and labels from the Philadelphia Academy of Natural Sciences collection, from one literature source (Godwin & Minich 2005), or were provided by Kendra Bauer and John Abbott (University of Texas, Austin).

Seasonality in Texas. See Fig. 37 . The adult seasonality profile of this species (based on 19 occurrence records: Appendix I) is unimodal, with a large peak in summer.

Biological notes. Nicrophorus americanus is the largest Nicrophorus species in North America . This species is univoltine (Backlund et al. 2008) and adults are fully nocturnal (Raithel 1991). Adults rear their young on large bird and small mammal carrion sources (Ratcliffe 1996). Crucial habitat features of the American burying beetle are based on the presence of carrion suitable for reproduction, vertebrate and invertebrate competitors for carrion, and soil sufficient for carcass burial (Amaral et al. 2008). There are numerous proposed explanations for the decline of the species (see Creighton et al. 2009, Sikes & Raithel 2002, Scott 1998, and Amaral et al. 2008 for reviews of major hypotheses).

Data from examined labels. Collecting methods: pit-fall trap. Habitat records: sandy meadow [pit-fall trap].

Figures

FIGURES 7 – 11. Details of Texas Silphidae. 7. Oiceoptoma inaequale, ventral view, wide elytral epipleuron; 8. Oiceoptoma rugulosum, ventral view, narrow elytral epilpeuron; 9. Nicrophorus carolinus, pronotum; 10. Nicrophorus americanus, pronotum; 11. Nicrophorus americanus, tarsal empodium quadrisetose.

FIGURES 24 – 30. Habitus of Texas Nicrophorus. 24, N. americanus; 25, N. carolinus; 26, N. marginatus; 27, N. mexicanus; 28, N. pustulatus; 29, N. orbicollis; 30, N. tomentosus. All scale bars = 10 mm.

FIGURES 37 – 42. Adult seasonality profiles based on occurrence records for Texas Silphidae, Nicrophorinae (part). 37, Nicrophorus americanus; 38, N. carolinus; 39, N. marginatus; 40, N. mexicanus; 41, N. orbicollis; 42, N. pustulatus. For an explanation of occurrence record calculations, see Methods.

FIGURES 50 – 55. Distribution maps for Texas Silphidae, Nicrophorinae (part). 50, Nicrophorus americanus; 51, N. carolinus; 52, N. marginatu s; 53, N. mexicanus; 54, N. orbicollis; 55, N. pustulatus.