Holostrophus bifasciatus ( Say, 1824 )

Pollock, Darren, 2008, Review of the Canadian Eustrophinae (Coleoptera, Tetratomidae), ZooKeys 2 (2), pp. 261-290 : 271-272

Holostrophus bifasciatus ( Say, 1824)

( Figs 3 , 10, 15 , 19 , 27 )

Eustrophus bifasciatus Say, 1824: 282 .— Melsheimer, 1853: 143; Blatchley, 1910: 1293; Leng, 1920: 238; Csiki, 1924: 9; Poole and Gentili, 1996: 299; LeSage, 1991: 246; Nikitsky, 1998: plate 9, figs 1-2; Young and Pollock, 2002: 416; Majka and Pollock, 2006: 53. Neotype (here designated), sex unknown, labelled “[faded pink circle] / E. bifasciatus Say 4-maculatus Mels.”, in MCZ (LeConte collection).

Eustrophus 4-maculatus Melsheimer, 1846: 58 .— Csiki, 1924: 9; Poole and Gentili, 1996: 299; LeSage, 1991: 246.

Diagnosis Holostrophus bifasciatus is the only Nearctic species of Eustrophinae with a distinct, quadrimaculate elytral color pattern.

Description TL 4.1-5.5 mm; GEW 1.9-2.5 mm. Body ( Fig. 3 ) elongate oval, distinctly tapered posteriorly; dorsal color dark rufous to almost black; in most specimens, color of pronotum lighter than color of elytra; elytra with 4 yellow-red, subquadrate maculae: anterior pair near humeri and not attaining suture, posterior pair in apical third of elytra, attaining suture in some specimens; antennomeres uniformly rufous in color, antennomere 11 slightly lighter in color than preceding articles; venter uniformly dark rufous; dorsal pubescence relatively short, inconspicuous; eyes ( Fig. 10 ) widely separated (space> 3x length of antennomere 1), inner margin of eye moderately deeply emarginate; antennae ( Fig. 19 ) relatively short, antennomeres 7-11 distinctly widened; antennomere 7 triangular, 8-10 distinctly wider than long; antennal sensilla completely annular (as in Fig. 25 ); last maxillary palpomere slightly widened, subsecuriform; procoxal process elongate, spatulate distally, extended to past posterior margin of procoxae, bent dorsally at distal end; prothoracic episternal suture absent; elytral punctation fine, not arranged in longitudinal striae; meso- and metatibiae with scattered short spines, oblique ridges absent ( Fig. 16 ).

Distribution ( Fig. 27 ) Holostrophus bifasciatus is an eastern species; in Canada, specimens have been collected from west of Lake Superior in northwestern Ontario,

east to Nova Scotia and Prince Edward Island. Most Canadian specimens are known from southern Ontario and Quebec. Th e species is very widespread in the eastern half of the United States, almost entirely east of the Mississippi. US distribution: AL, AR, CT, DC, DE, FL, GA, IA, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, NC, NH, NJ, NY, OH, PA, SC, TN, TX, VA, WI, WV.

Natural history Label data: Laetiporus sulphureus (AR); ex polypore in pine logs (AR); Trametes versicolor (AR); Schizopora paradoxa (AR); BLT (June, AL); ex polypore on cherry tree (AR); under loose pine bark (DE); under pine bark (GA); Malaise trap (March, June, GA); oak log (IL); sugar trap (May, IL); UV light (April, IL); flight trap (Aug-Sept, IL). According to Chantal (1985), specimens of H. bifasciatus have been taken under bark of dead Pinus strobus on which was growing polypore fungi, as well as from Polyporus betulinus .

Material examined Specimens were examined from the following Canadian localities: ONTARIO: Arnprior , 26.V.1935, W.J. Brown, ( CNC, 12) ; Essex Co., Windsor Ojibway Prairie , 7.VIII.2001, S. Paiero, Sweeps, ( DEBU, 1) ; Jeannette Creek , 3.VIII.1965, ( FSCA, 1) ; Ottawa , ( CNC, 6) ; same locality, ( CUIC, 1) ; Peel Co., Port Credit , 10.IV.1966, I.M. Smith, ( ROME, 1) ; Tillsonburg , 11.VII.1958, ( CNC, 1) ; Toronto , 20.XI.1895, R.J. Crew, ( CUIC, 1) ; no other data, ( DEBU, 3) ; London, W. Saunders, ( DEBU, 1) ; Ridgeway, ( DEBU, 2). QUEBEC: Gatineau , Aylmer , 17.V.1992, Y. Bousquet, in flight, ( SLC, 1). PRINCE EDWARD ISLAND: Queens Co., St. Patricks , 25.VI.2003, C.G. Majka, coniferous forest, ( CGMC, 2). NOVA SCOTIA: Halifax Co., Pt. Pleasant Park, 15.VII.2001, C.G. Majka, mixed forest, deciduous vegetation, ( CGMC, 1) .

Figures

Figs 1-7. Dorsal habitus of Canadian eustrophines. Fig. 1. Pseudoholostrophus impressicollis, TL = 4.3 mm; Fig. 2. Pseudoholostrophus discolor, TL = 4.8 mm; Fig. 3. Holostrophus bifasciatus, TL = 5.8 mm; Fig. 4. Eustrophus tomentosus, TL = 4.8 mm; Fig. 5. Eustrophopsis bicolor, TL = 5.6 mm; Fig. 6. Eustrophopsis confinis, TL = 5.4 mm; Fig. 7. Synstrophus repandus, TL = 6.8 mm.

Figs 8-16. Features of Canadian eustrophines. Figs. 8-14. Frontal view of head (same specimens as in Figs. 1-7). Fig. 8. Pseudoholostrophus impressicollis; Fig. 9. Pseudoholostrophus discolor; Fig. 10. Holostrophus bifasciatus; Fig. 11. Eustrophus tomentosus; Fig. 12. Eustrophopsis bicolor; Fig. 13. Eustrophopsis confinis; Fig. 14. Synstrophus repandus. Figs. 15-16. Hind tibia. Fig. 15. H. bifasciatus; Fig. 16. E. tomentosus.

Figs 17-25. Antennae of Canadian eustrophines. Fig. 17. Pseudoholostrophus impressicollis; Fig. 18. Pseudoholostrophus discolor; Fig. 19. Holostrophus bifasciatus; Fig. 20. Eustrophus tomentosus; Fig. 21. Eustrophopsis bicolor; Fig. 22. Eustrophopsis confinis; Fig. 23. Synstrophus repandus; Fig. 24. E. tomentosus, antennomeres 9-11 (sensillar field indicated by stippling); Fig. 25. S. repandus, antennomeres 9-11 (sensillar field indicated by stippling). Scale bar = 0.25 mm (Figs. 17-23); 0.1 mm (Figs. 24-25).

Fig. 27. Canadian distribution of Holostrophus bifasciatus. Inset shows US distribution, by state.