Difference between revisions of "Pachybrachis nigricornis"

Latest revision as of 14:39, 19 September 2013

Taxonavigation

Ordo: Coleoptera
Familia: Chrysomelidae
Genus: Pachybrachis

Name

Pachybrachis nigricornis (Say, 1824) – Wikispecies link – Pensoft Profile

• Cryptocephalus nigricornis Say, 1824: 436.
• Pachybrachys carbonarius Haldeman, 1849: 260.
• Pachybrachys autolycus Fall, 1915: 458.
• Pachybrachys autolycus var. Pachybrachis difficillis Fall, 1915: 459.
• Pachybrachys autolycus var. Pachybrachis wahsatchensis Fall, 1915: 459.
• Pachybrachys carbonarius var. Pachybrachis janus Fall, 1915: 462.

Recognition

Pronotum strongly alutaceous and opaque, more finely punctate than elytra. In subspecies Pachybrachis difficilis, black stripes usually complete and distinct (Habitus 9a), but in some specimens fused together. In subspecies Pachybrachis carbonarius, elytra largely black (Habitus 9b), margined with yellow, or with yellow at edge of elytra in some females (Habitus 9c); male size small: length 2.20 ± 0.14 mm, width 1.21 mm ± 0.06 mm (Pachybrachis difficilis); length 2.10 ± 0.07 mm, width 1.17 ± 0.04 mm (Pachybrachis carbonarius).

Distribution

The species Pachybrachis nigricornis is distributed across the eastern two-thirds of North America (Riley et al. 2003^[1]). The distribution of the subspecies remains a subject of debate (Balsbaugh and Tucker 1976^[2]; Barney and Hall 2009^[3]) (Map 9).

Material examined

NEW BRUNSWICK: Kent Co., Kouchibouguac National Park, 7.VII.1978, Code 7785K, H. Goulet [3♂, CNC]; same data except Code 7754F [1♂ 1♀, CNC]; same data, except 13.VII.1977, code 5599I, G.A. Calderwood [1♂ 1♀, CNC]; same data, except 4.VIII.1977, code 5779G [1♂, CNC]; same data, except 25.VIII.1977, code 5849Y, S.J. Miller [1♂ 1♀, CNC]; Queens Co., Jemseg, 18.VI.1981, ex. Potentilla simplex, L. LeSage & D. Ward [1♀, CNC].
ONTARIO: Carleton Co., Britannia, 14.VI.1949, R. de Ruette [2♀, CNC]; Constance Bay, 12.VII.1996, lot 3, B. F. & J. L. Carr [1♀, CNC]; Innis Point, 9–16.VII.1985, Interception trap, J. Denis & L. Dumouchel [1♂, CNC]; Ottawa, 17.VII.1912, G. Ouellet [1♀, IDM]; Hasting Co., Trenton, 28.V.2000, Evans [1♂, CNC]; Kenora Co., Berens River, 4–9.VII.1938, W. J. Brown [1♂ 1♀, CNC]; Hwy 17, 15 km east of Borups Corners, 23.VI.1996, lot 2, B. F. & J. L. Carr [1♀, CNC]; Leeds Co., Saint-Lawrence Island National Park, Grenadier Island Center, 27.V.1975, sweeping, E. Sigler [1♀, CNC]; Lennox - Addington Co. Kaladar, 21.VII.1996, lot 3, B. F. & J. L. Carr [1♂, CNC]; Muskoka Co., Bala, 24.VI.1956, W. J. Brown [3♂ 11♀, CNC]; Nipissing Co., Algonquin Provincial Park near Brent, 19.VIII.1980, R. Baranowski [1♀, CNC]; Hwy11, 30 km north of North Bay, 14.VII.1995, lot 3, B. F. & J. L. Carr [1♂ 1♀, CNC]; Hwy 17, 13 km west of Mattawa, 14.VI.1995, lot 1, B. F. & J. L. Carr [2♀, CNC]; Parry Sound Co., Parry Sound, 12.VII.1961, G. Brumpton [2♂, CNC]; same data, except 12.VII.1995, lot 1, B. F. & J. L. Carr [1♂, CNC]; Hwy 69, 12 km south Shawanaga, 13.VII.1995, Lot 3, B. F. & J. L. Carr [1♀, CNC]; Prescott Co., Alfred Bog, 8.VI.1982, breeding, ex. Cassandra calyculata, L. LeSage [4♂ 4♀, CNC]; same data, except 4.VI.1982, ex. Ericaceae [2♂ 4♀, CNC]; Prince Edward Co., 23.VI.1933, J. F. Brimley [1♀, CNC]; same data, except 1.VII.1936 [1♂, CNC]; same data, except 28.VI.1939 [1♂, CNC]; same data, except 19.VII.1942 [1♂, CNC]; same data, except 11–18.VI.1947 [12♂ 7♀, CNC]; same data, except 9.VI.1948 [8♂ 7♀, CNC]; same data, except 21.VI.1950 [2♀, CNC]; same data, except 17.VI.1953 [8♂ 14♀, CNC]; same data, except 19.VII.1961 [1♂, CNC]; same data, except 2.VII.2000, Evans [1♀, CNC]; Russell Co., Mer Bleue, 13.VI.1932, W. J. Brown [2♂ 1♀, CNC]; same data, except 30.VI.1932 [5♂, CNC]; same data, except 26.VII.1932 [1♂, CNC]; same data, except 30.VI.1934 [1♂, CNC]; same data, except 10.VIII.1936 [1♂, CNC]; same data, except 25.VII.1932, L. J. Milne [6♂ 3♀, CNC]; same data, except 29.VI.1954, E. C. Becker [2♂ 2♀, CNC]; same data, except 3.VII.1981, ex. Cassandra calyculata, L. LeSage [1♂ 1♀, CNC]; same data, except 30.VII.1979, sweeping, H. Goulet [1♂, CNC]; Sudbury Co., Sudbury, 1898 [1♀, CNC]; Thunder Bay Co., Manitouwadge, paper yard, 3.VII.1985, T. Baker [1♂ 1♀, CNC]; 59 km north junction of highways 516 & 599, 24.VI.1992, lot 1 B. F. & J. L. Carr [1♂, CNC].
QUÉBEC: Beauce Co., Beauceville, 21.VI.1937, Frère Étienne-Maurice [1♀, CEUM]; Bonaventure Co., Cascapédia, 22.VI.1933, W.J. Brown [1♂ CNC]; same data, except 9.VII.1933 [1♂, CNC]; same data, except 16.VIII.1933 [1♀, CNC]; Châteauguay Co., Ormstown, 12.VII.1977, E. J. Kiteley, sweeping [1♂, CNC]; Deux-Montagnes Co., La Trappe, VII.1933 [1♂ 1♀, Pachybrachis autolycus, var. Pachybrachis difficillis Fall, Fall-MCZ]; same data, except 25.V.1929, P. Leopold [4♀, CEUM]; same data, except 2–19.VI.1936 [1♀, CEUM]; same data, except 21.VI.1933, J. Ouellet [5♂ 3♀, CEUM]; same data, except 23.VII.1933 [1♂, CEUM]; same data, except 3–28.VII.1934 [2♂ 1♀, CEUM]; same data, except 3–17.VII.1935 [1♂ 1♀, CEUM]; same data, except 15.VI.1946 [1♂, CEUM]; Gatineau Co., Aylmer, 11.VI.1932, W. J. Brown [6♂ 4♀, CNC]; Gracefield, 22.VI.1937, O. Peck [1♂, CNC]; Kazabazua, 28.VIII.1928, W. J. Brown [1♀, CNC]; Lytton, 1.VII.1981, weeds, side of road, A. Larochelle [1♂, CNC]; Mont King, Parc de la Gatineau 7–14.VII.1997, L. LeSage & C. Lacroix [1♂ CNC]; Huntingdon Co., Saint-Antoine- Abbé, 16.VI.1983, fern, A. Larochelle [2♀, CNC]; Joliette Co., Joliette, 12.VII.1922, J. Ouellet [1♂ 2♀, CEUM]; Labelle Co., Nominingue, 21.VII.1932 [1♂, Pachybrachis autolycus, var. Pachybrachis difficillis Fall, Fall-MCZ]; same data, except 12–19.VII.1932, J. Ouellet [4♂ 3♀, CEUM]; same data, except 4.VII.1934, L. Daviault [1♀, CEUM]; Lac-Saint-Jean-Ouest Co., Mistassini, 28.VII.1944, A. Robert [1♂ 1♀, CEUM]; Montcalm Co., Parc du Mont-Tremblant, 22.VI.1956, A. Robert [1♀, CEUM]; same data, except 11.VII.1961 [1♀, CEUM]; Pontiac Co., Beech Grove, 10.VIII.1966, H. Goulet [1♂, CNC]; Portneuf Co., Sainte-Catherine, 3.VII.1956, J. C. Aubé [1♀, LEMC]; Territoires-du-Nouveau-Québec Co., Casa-Berardi, 22–29.VI.1997, interception trap, P. Paquin [2♂, LEM]; same data, except 6–27.VII.1997 [4♂ 2♀, LEM]; same data, except 3–24.VIII.1997 [3♂ 1♀, LEM]; Chemin Selbale, 6–27.VII.1997, interception trap, P. Paquin [1♂ 4♀, LEM].

Host plants

Although over 200 specimens were examined, the only potential host plants recorded by collectors were Cassandra calyculata (L.) D. Don (Ericaceae) and Potentilla simplex Michx. (Rosaceae). Balsbaugh and Tucker (1976)^[2] reported that they collected series of Pachybrachis carbonarius on wild strawberry (Fragaria sp.) (Rosaceae), and tick-trefoil (Desmodium sp.) (Fabaceae) in Alabama. Barney and Hall (2009)^[3] reared the same subspecies on Desmodium paniculatum L. DC and Lespedeza virginica (L.) Britton (Fabaceae) in Kentucky.

Comments

Balsbaugh and Tucker (1976)^[2] and Riley et al. (2003)^[1] recognized Pachybrachis nigricornis as having four subspecies in North America. Fall (1915)^[4] described Pachybrachis autolycus as a separate species with two “varieties”, and he added the variety Pachybrachis janus to Pachybrachis carbonarius, which he also recognized as a separate species. Specimens from each of the provinces of NB, ON and QC included an assortment of var. Pachybrachis carbonarius, var. Pachybrachis difficilis, and the yellow variation of Pachybrachis carbonarius as per Barney and Hall (2009)^[3]. In the “Material examined” section above, the QC specimens from Fall’s personal collection (Fall-MCZ) are listed, with an indication of his identification label of Pachybrachis autolycus, var. Pachybrachis difficillis.

Taxon Treatment

• Barney, R; LeSage, L; Savard, K; 2013: Pachybrachis (Coleoptera, Chrysomelidae, Cryptocephalinae) of Eastern Canada ZooKeys, 332: 95-175. doi

Other References

1. ↑ ^{1.0 1.1} Riley E, Clark S, Seeno T (2003) Catalog of the leaf beetles of America north of Mexico (Coleoptera: Megalopodidae, Orsodacnidae and Chrysomelidae, excluding Bruchinae). Coleopterists Society, Special Publication no. 1, 290 pp.
2. ↑ ^{2.0 2.1 2.2} Balsbaugh E, Tucker W (1976) Geographical variation in Pachybrachis nigricornis (Coleoptera: Chrysomelidae). The Coleopterists Bulletin 30(2): 117-131.
3. ↑ ^{3.0 3.1 3.2} Barney R, Hall S (2009) Pachybrachis nigricornis carbonarius Haldeman (Coleoptera: Chrysomelidae): abundance, distribution, and host plant associations with legumes (Fabales: Fabaceae) in Kentucky. The Coleopterists Bulletin 63(4): 467-474. doi: 10.1649/1180.1
4. ↑ Fall H (1915) A revision of the North American species of Pachybrachys. Transactions of the American Entomological Society 41: 291-486.

Images

Figure 6. Pronotum: a reddish, with close-up of marginal bead, Pachybrachis bivittatus b mottled, Pachybrachis spumarius c with black M-mark, Pachybrachis m-nigrum d almost black, Pachybrachis nigricornis carbonarius.  Figure 7. Elytral punctures and coloration: a in rows in deep striae, Pachybrachis luctuosus b confused in basal half, in rows in apical half, Pachybrachis calcaratus c all confused, Pachybrachis hepaticus d confused and mottled, Pachybrachis spumarius e vittate with marginal vitta interrupted, Pachybrachis bivattatus f black, margined with yellow, Pachybrachis nigriconis carbonarius g entirely black, Pachybrachis luridus.  Habitus 9a. Dorsal habitus of Pachybrachis nigricornis difficilis. Scale bar, 1 mrn.  Habitus 9b. Dorsal habitus of Pachybrachis nigricornis carbonarius. Almost black. Scale bar, 1 mm.  Habitus 9c. Dorsal habitus of Pachybrachis nigricornis carbonarius. Yellow at edge of elytra. Scale bar, 1 mm.  Map 9. The known distribution of Pachybrachis nigricornis in eastern Canada. SR – Saguenay River.