Pachybrachis hepaticus hepaticus (F. E. Melsheimer, 1847)

Barney, Robert J., LeSage, Laurent & Savard, Karine, 2013, Pachybrachis (Coleoptera, Chrysomelidae, Cryptocephalinae) of Eastern Canada, ZooKeys 332, pp. 95-175 : 116-117

Pachybrachis hepaticus hepaticus (F. E. Melsheimer, 1847) Habitus 5 ; Map 5 ; Figures 1c , 3a , 7c

Cryptocephalus hepaticus F. E. Melsheimer, 1847: 171.

Cryptocephalus punctatus Haldeman, 1849: 257.

Recognition.

Front femora not enlarged in comparison to those of middle and hind legs ( Figure 3a ); eyes small and remote ( Figure 1d ); antennae short, less than half body length ( Habitus 5 ); integument densely, diffusely punctate ( Figure 7c ); elytra tapered to apex; male size very small: length 1.68 ± 0.07 mm, width 0.96 ± 0.07 mm.

Distribution.

Transcontinental, extending from California to Maine ( Riley et al. 2003). In eastern Canada, Pachybrachis hepaticus hepaticus occurs in southern Ontario from Lake Ontario to the Ottawa River Valley in Québec ( Map 5 ).

Material examined.

ONTARIO: Carleton Co., Jockevale, 4.VII.1934, W. J. Brown [1♂, CNC]; Ottawa, 24.VI.1995, [ex. field notes: "pinery forest preserve, on sand dunes …”], B. F. & J. L. Carr [1♀, CNC]; Essex Co., Leamington, 3.VII.1931, W. J. Brown [1♀, CNC]; same data, except 17.VI.1940 [1♂, CNC]; Point Pelee, 24.VI.1931, W. J. Brown [1♂, CNC]; Haldimand-Norfolk Cos., Turkey Point, 24.VII.1984, sweeping in marshy area, L. LeSage [1♀, CNC]; Hasting Co., 10.VII.1938, Brimley [1♀, CNC]; Norfolk Co., Forestville, 15.VI.1931, W. J. Brown [1♂, CNC]; Parry Sound Dist., Scotia Junction, 28.VII.1934, H. W. Wenzel [1♂ 1♀, OSUC]; Prince Edward Co., 22.VI.1919, Brimley [1♀, CNC]; same data, except 28.VI.1921 [1♂, CNC]; same data, except 2.VIII.1925 [1♀, CNC]; Renfrew Co., Arnprior, 20.VII.1941, W. J. Brown [1♀, CNC]; Russell Co., Mer Bleue, 18.VI.1986, W. J. Brown [1♂, CNC]; same data, except 10.VII.1936 [1♀, CNC]; Toronto Co., Toronto, F. Knab [1♀, USNM]; same data, except 26.V.1896, R. J. Crew [1♀, ROM]. Unknown Co., East Ontario, 1885 [1♀, CNC].

QUÉBEC: Deux-Montagnes Co., La Trappe, 30.VI.1931, J. Ouellet [1♂, CEUM]; same data, except 27-29.VI.1933 [21♂ 15♀, CEUM]; same data, except 23.VII.1933 [1♀, CEUM]; same data, except 28.VII.1934 [1♀, CEUM]; same data, except 20.VIII.1936 [1♂, CEUM]; same data, except 26.VIII.1946 [1♀, CEUM]; same data, except 7.VII.1949 [1♂, CEUM]; Gatineau Co., Alcove, 24.VIII.1936, W. J. Brown [1♀, CNC]; Gatineau Park, Meach Lake, 30.VII.1972, A. Davies [1♀, CNC]; Wakefield, 20.VII.1932, W. J. Brown [2♀, CNC]; Wright, 27.VI.1933, G. S. Walley [1♂, CNC]; Labelle Co., Nominingue, 29.VII.1931, J. Ouellet [3♀, CEUM]; same data, except 6-21.VII.1932 [20♂ 13♀, CEUM]; same data, except 4.VII.1933 [2♂ 1♀, CEUM]; same data, except 2.VII.1934 [1♂, CEUM]; same data, except 8.VII.1935 [1♂, CEUM]; same data, except 22.VII.1936 [2♀, MSUC]; same data, except 2.VIII.1936 [1♂, CEUM].

Host plants.

No plant association records were available from specimens examined. Pachybrachis hepaticus hepaticus may be a polyphagous species, considering the number of plant families listed in Clark et al. (2004): Asteraceae , Euphorbiaceae , Fabaceae , Juncaceae , Salicaceae , and Tamaricaceae .

Comments.

Of all the species here studied, the shortest antennae ( Habitus 5 ) and smallest eyes are found in Pachybrachis hepaticus hepaticus . Further investigation may require that a new genus is established for the eastern and western subspecies of Pachybrachis hepaticus . Fall (1915) cited specimens from Montréal, May 24 (Liebeck Coll.); Toronto (Crew); and Scotia Junction, July 27 (Wenzel), but these specimens could not be located and examined.

Figures

Figure 1. Eyes: a close eyes, Pachybrachis pectoralis b normal eyes, Pachybrachis peccans c normal eyes and yellow face, male Pachybrachis atomarius d remote eyes, Pachybrachis hepaticus.

Figure 3. Front femora: a not enlarged, Pachybrachis hepaticus b thickened, Pachybrachis peccans.

Habitus 5. Dorsal habitus of Pachybrachis hepaticus hepaticus. Scale bar, 1 mm.

Map 5. The known distribution of Pachybrachis hepaticus hepaticus in eastern Canada. OL - Ontario Lake; OR - Ottawa River.

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.