Oiceoptoma inaequale (Fabricius, 1781)

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 : 226

Oiceoptoma inaequale (Fabricius, 1781)

Figs. 6 , 7 , 20 , 33 , 46

Silpha inaequalis Fabricius, 1781: 87 .

Diagnosis. Body length 13–16 mm, broadly oval to subparallel, entirely black. Head with short row of long, erect hairs behind each eye. Pronotum broadest at base, disc with short black hairs. Elytral apices conjointly rounded; humerus with tooth; disc tricostate, intervals distally with weak rugulose sculpturing; epipleuron wide in posterior half with upper oblique portion twice width of lower vertical portion, coloration not differing from remainder of body. Hind femur of males unmodified.

Range. Quebec south to Florida, west to Ontario, South Dakota and Texas (Anderson & Peck 1985, Peck & Kaulbars 1987).

Texas distribution. See Fig. 46 . This species is confined to the Texan and Austroriparian biotic provinces of Texas. It occurs in the following Texas vegetational areas: pineywoods, gulf prairies and marshes, post oak savannah, blackland prairies, and cross timbers and prairies. Confirmed counties (30): Brazos, Cherokee, Cooke, Dallas, Delta, Denton, Ellis, Falls, Fannin, Grimes, Harris, Harrison, Houston, Hunt, Jackson, Lamar, Leon, Madison, McLennan, Montague, Nacogdoches, Newton, Parker, Polk, Robertson, Sabine, San Jacinto, Smith, Tyler, Walker, Wood. Collections: BRC, EGRC, JAC, PLM, SFAC, SHSU, TAMU, TORC, TTU, UTIC, WTAM.

Seasonality in Texas. See Fig. 33 . The adult seasonality profile of this species (based on 117 occurrence records: Appendix I) is unimodal, with a large peak in spring.

Biological Notes. Anderson and Peck (1985) report that adults are mainly diurnal and appear to be restricted to deciduous forest habitats. In Kansas, this species prefers wooded areas but is often present in open fields (Lingafelter 1995).

Data from examined labels. Collecting methods: hanging sugarbait trap, flight intercept trap, UV light, Lindgren funnel trap, pit-fall trap, hanging carrion trap, elevated flight intercept trap, Malaise trap, baited pit-fall trap. Habitat records: grassland [Malaise], beech–magnolia forest [pit-fall trap and Lindgren funnel trap], upland forest [flight intercept trap], bottomland forest [hanging sugarbait trap], in leaf litter, beating Quercus marylandica , and in rotting logs. Carrion records: snake/squirrel [hanging carrion trap], deer, opossum, dog, tiger [dead zoo specimen], pig, cat, shad, and cow. This species is present in the eastern forested biotic provinces of Texas, with a few records in the open prairie vegetational areas in the northeastern area of the state. Anderson (1982), Schubeck (1983), Cole (1942) and Watson and Carlton (2005) provide details on the natural history of this species.

Figures

FIGURES 1 – 6. Details of Texas Silphidae. 1. Nicrophorus pustulatus, presence of epistomal suture; 2. Nicrophorinae, antenna; 3. Necrophila americana, absence of epistomal suture; 4. Silphinae, antenna; 5. Necrodes surinamensis, pronotum; 6. Oiceoptoma inaequale, pronotum.

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 18 – 23. Habitus of Texas Silphidae. 18, Necrophila americana; 19, Necrodes surinamensis; 20, Oiceoptoma inaequale; 21, O. noveboracense; 22, O. rugulosum; 23, Thanatophilus truncatus. All scale bars = 10 mm.

FIGURES 31 – 36. Adult seasonality profiles based on occurrence records for Texas Silphidae, Silphinae. 31, Necrophila americana; 32, Necrodes surinamensis; 33, Oiceoptoma inaequale; 34, O. noveboracense; 35, O. rugulosum; 36, Thanatophilus truncatus. For an explanation of occurrence record calculations, see Methods.

FIGURES 44 – 49. Distribution maps for Texas Silphidae, Silphinae. 44, Necrophila americana; 45, Necrodes surinamensis; 46, Oiceoptoma inaequale; 47, O. noveboracense; 48, O. rugulosum; 49, Thanatophilus truncatus.