Pachybrachis othonus othonus (Say, 1825)

Barney, Robert J., LeSage, Laurent & Savard, Karine, 2013, Pachybrachis (Coleoptera, Chrysomelidae, Cryptocephalinae) of Eastern Canada, ZooKeys 332, pp. 95-175 : 124-125

Pachybrachis othonus othonus (Say, 1825) Habitus 11 ; Map 11

Cryptocephalus othonus Say, 1825: pl. 28.

Cryptocephalus marginaticollis Randall, 1838: 46.

Recognition.

Body robust. Pronotum black, with all margins and narrow median anterior stripe yellow; each elytron black, with rather narrow sub sutural, discal and marginal vittae yellow; legs yellow. Punctures of pronotum larger and denser than those on elytra; elytral punctures in somewhat regular rows on disc and sides ( Habitus 11 ); male size medium: length 2.63 ± 0.12 mm, width 1.56 ± 0.09 mm.

Distribution.

A typical eastern species distributed from North Dakota to Texas to the Atlantic Coast in the United States ( Riley et al. 2003), and in the south of Ontario and Québec in eastern Canada ( Map 11 ).

Material examined.

ONTARIO: Carleton Co., Britannia, 17.VI.1948, S. D. Hicks [1♂, CNC]; same data, except 23.VI.1950, R. de Ruette [1♀, CNC]; Constance Bay, 14.VII.1950, S. D. Hick [1♀, CNC]; Dirleton, 4.VII.1956, S. D. Hicks [1♀, CNC]; Ottawa, 7.VIII.1914, F. G. Ouellet [1♂, IDM]; same data, except 15.VII.1957, J. E. H. Martin [1♂, CNC]; Essex Co., Leamington, 24.VI.1940, W. J. Brown [1♀, CNC]; Ojibway, 27.VI.1943, S. D. Hicks [1♀, CNC]; same data, except 10.VI.1944 [1♂, CNC]; Roseland, 17-24.VI.1944, S. D. Hicks [1♂ 3♀, CNC]; same data, except 17.VI.1946 [2♀, CNC]; same data, except 30.VI.-13.VII.1946 [2♂ 9♀, CNC]; Halton Co., Burlington, 1920, G. M. Stirrett [1♂ 1♀, CNC]; Hastings Co., Chatterton, 16.VII.1950, J. F. Brimley [2♂, CNC]; same data, except 2.VII.1951, J. C. Martin [1♀, CNC]; Marmora, 6.VII.1951, J. F. McAlpine [1♂, CNC]; same data, except 29.VIII.1952, C. Boyle [1♂, CNC]; Lanark Co., Bell’s Corners, 15-26.VI.1950, S. D. Hicks [1♂ 2♀, CNC]; same data, except 4.VII.1950 [1♀, CNC]; Niagara Co., St. Catherines, Decew Falls, 27.VII.1940, S. D. Hick [1♀, CNC]; Toronto Co., Kingsport, 3.VII.1965, D. D. Munroe [1♂ 1♀, CNC]; Toronto, 26.VI.1896, C. T. Hills [1♂ 2♀, LEM]; same data, except 27.V.1896 [1♂ 2♀, LEM]; same data, except 9.VI.1905, E. C. Oakley [3♀, ROM]; same data, except F. Knab [3♂ 1♀, USNM]; Wentworth Co., Ancaster, 10.VII.1965, J. E. Martin [2♂, CNC].

QUÉBEC: Berthier Co., Berthierville, 27.VII.1938, J. Ouellet [1♀, CEUM]; same data, except 8.VII.1950 [1♀, CEUM]; Lanoraie, 1.VII.1932 [1♂, CEUM]; Chambly Co., Boucherville, 1.VII, J. Ouellet [1♀, CEUM]; Deux-Montagnes Co., Saint-Eustache, 12.VIII.1917, J. Ouellet [2♀, CEUM]; Saint-Placide, 13.VII.1931, J. Ouellet [1♀, CEUM]; Gatineau Co., Aylmer, 21.VII.2009, ex. Hypericum , Lythrum , Daucus , graminées, etc, L. LeSage [1♀, CNC]; Île-de- Montréal Co., Montréal, 14.VII.1904, Beaulieu [1♀, USNM]; Joliette Co., Joliette, 12.VII.1909, J. Ouellet [1♀, CEUM]; same data, except 7-13.VII.1922 [29♂ 46♀, CEUM]; Napierville Co., Saint-Rémi, 1.VII.1920, J. Ouellet [1♂ 1♀, CEUM]; Papineau Co., Montebello, 16.VII.1937, J. Ouellet [1♀, CEUM]; Pontiac Co., Beech Grove, 18.VII.1951, J. F. McAlpine [1♀, CNC]; Yarm, 23.VII.1955, C. H. Mann [1♂, CNC]; Vaudreuil Co., Hudson Heights, 24-30.VII.1956, Lindberg [1♀, CNC]; Rigaud, 5.VII.1920, J. Ouellet [2♂ 1♀, CEUM].

Host plants.

No specific plant associations were recorded on labels of specimens examined. Chagnon (1937, 1940) and Chagnon and Robert (1962) gave willow ( Salix sp.) ( Salicaceae ) as a host in Québec, but Pachybrachis othonus was reported on a large number of questionable “hosts” by authors (details in Clark et al. 2004). Barney and Hall (2011) reported feeding, mating and oviposition on Desmodium marilandicum (L.) ( Fabaceae ).

Comments.

Balsbaugh (1973) and Riley et al. (2003) recognized Pachybrachis othonus as having three subspecies in North America.More information on habitats and hosts are needed on Pachybrachis othonus othonus , which is one of the easiest species to recognize.

Figures

Habitus 11. Dorsal habitus of Pachybrachis othonus othonus. Scale bar, 1 mm.

Map 11. The known distribution of Pachybrachis othonus othonus in eastern Canada. OR - Ottawa River; SLR - St. Lawrence River.