Pachybrachis trinotatus (F. E. Melsheimer, 1847)

Barney, Robert J., LeSage, Laurent & Savard, Karine, 2013, Pachybrachis (Coleoptera, Chrysomelidae, Cryptocephalinae) of Eastern Canada, ZooKeys 332, pp. 95-175 : 132

Pachybrachis trinotatus (F. E. Melsheimer, 1847) Habitus 17 ; Map 17

Cryptocephalus trinotatus F. E. Melsheimer, 1847: 170.

Pachybrachis trinotatus

Recognition.

Pronotum red with heavy, sharply defined, black M-mark, and with pale anterior and lateral margins; elytra entirely black ( Habitus 17 ); male size large: length 3.09 ± 0.13 mm, width 1.75 ± 0.09 mm.

Distribution.

Pachybrachis trinotatus is an eastern species distributed from Kansas to the Atlantic Coast in the United States ( Riley et al. 2003), and in Ontario and Québec in eastern Canada ( Map 17 ).

Material examined.

ONTARIO: Carleton Co., Stittsville, 26.VII.1961, G. Brumpton [1♂, CNC]; Essex Co., Leamington, 27.VI-3.VII.1931, W. J. Brown [1♂ 1♀, CNC]; Hamilton Co., Ancaster, 2.VII.1958, J. E. H. Martin [1♂, CNC]; Hastings Co., 10.VII.1938, J. F. Brimley [1♀, CNC]; same data, except 24.VII.1960, J. F. Brimley [1♂ 1♀, CNC]; Marmora, 2.VII.1952, C. Boyle [1♀, CNC]; Lambton Co., Grand Bend, 10.VII.1939, G. E. Shewell [1♂ 1♀, CNC]; Lanark Co., Bell’s Corners, 15.VII.1954, S. D. Hicks [3♂ 2♀, CNC]; same data, except Lanark, Kerr Lake 13.VII.1975 [1♂, CNC]; Lincoln Co., DeCew Falls, 29.VI.1940, S. D. Hicks [1♂, CNC]; same data, except 27.VII.1940 [1♂ 1♀, CNC]; same data, except VIII.1941 [1♂, CNC]; Northumberland Co., Hamilton, 14-19.VII.1984, M. Sanborne [1♀, CNC]; Prince Edward Co., 21.VII.1937, beaten from oak, J. F. Brimley [1♀, CNC]; same data, except 4.VII.1946 [1♀, CNC]; same data, except 11.VIII.1947 [1♀, CNC]; same data, except 14.VII.1948 [1♀, CNC]; same data, except 10.VIII.1948 [1♀, CNC]; same data, except 20.VI.1949 [1♂, CNC]; same data, except 6.VII.1949 [1♀, CNC]; same data, except 17.VII.1950 [5♂ 3♀, CNC; 1♂, AMNH; 2♂ 1♀, St. John’s wort blossom, FSCA]; same data, except 7.VII.1955 [1♂, CNC]; same data, except 29.VII.1956 [1♀, CNC]; same data, except 27.VII.1962 [1♂ 1♀, CNC]; Renfrew Co., Hwy 512 15 km W Eganville, 5.VII.1996, B. F. & J. L. Carr [1♂, CNC]; Simcoe Co., Craighurst, 30.VIII.1963, G. G. E. Scudder [1♀, CNC]; Tiny Township, Cawaja Beach, 17.VII.1968, J. C. E. Riotte [1♂ 1♀, ROM]; Toronto Co., Toronto, Kelly Lake, 13-26.VII.1933, L. J. Milne [2♂ 1♀, UNHC]; Victoria Co., Coboconk, 7.VIII.1940, S.D. Hicks [1♀, CNC]; Wellington Co., Guelph, VII.1924, D. C. B. Duff [1♂, ROM].

QUÉBEC: Huntingdon Co., Covey Hill, 1.VII.1927, W. J. Brown [1♂, CNC]; Île-de-Montréal, Montréal, 10.VII.1977, sweeping field, E. J. Kiteley [1♂, CNC]; Missisquoi Co., Phillipsburg, 31.VII.1972, J. L. Laliberté [1♂, IDM]; Québec Co., Québec, 26.VII.1902, F. Knab [1♂ 1♀, USNM]; Vaudreuil Co., Hudson Heights, 24-30.VII.1956, Lindberg [1♀, CNC]; Rigaud 29.VI.1907, J. Ouellet [1♂, CEUM]; same data, except 18.VIII.1921 [2♂, CEUM]; same data, except 23.VII.1974, E. J. Kiteley [2♀, CNC].

Host plants.

No information was available from specimens examined. Barney and Hall (2011) reported handpicking specimens from St. John’s wort, Hypericum punctatum L. ( Clusiaceae ), and observed feeding, mating and oviposition on Hypericum punctatum , Hypericum perforatum L. and Hypericum dolabriforme Vent. in the lab. Following Banks (1912), New Jersey tea, Ceanothus americanus L. ( Rhamnaceae ) was often given by authors as a host for Pachybrachis trinotatus (complete citation in Clark et al. 2004).

Comments.

With its black elytra and reddish pronotum ornamented with a large, black, M-shaped marking, Pachybrachis trinotatus is very easily distinguished from all other Canadian species of the genus ( Habitus 17 ). It is widely distributed in southern Ontario but is found only in the Ottawa River Valley and south of the eastern Townships in Québec ( Map 17 ). Both areas very likely represent its northernmost distribution limit in this province.

Figures

Habitus 17. Dorsal habitus of Pachybrachis trinotatus. Scale bar, 1 mm.

Map 17. The known distribution of Pachybrachis trinotatus in eastern Canada.