Pachybrachis (Coleoptera, Chrysomelidae, Cryptocephalinae) of Eastern Canada
Author
Barney, Robert J.
Gus R. Douglass Land-Grant Institute, West Virginia State University, Institute, West Virginia, United States 25112 - 1000
rbarney@wvstateu.edu
Author
LeSage, Laurent
Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre, Neatby Building, Ottawa, Ontario, Canada K 1 A 0 C 6
Author
Savard, Karine
Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Centre, Neatby Building, Ottawa, Ontario, Canada K 1 A 0 C 6
text
ZooKeys
2013
2013-09-19
332
95
175
http://dx.doi.org/10.3897/zookeys.332.4753
journal article
http://dx.doi.org/10.3897/zookeys.332.4753
1313-2970-332-95
9C1CE036FFBF8D66FF024F74FFB0FFCC
577540
Pachybrachis bivittatus (Say, 1824)
Habitus 2
; Map 2
; Figures 6a
, 7e
, 8a
, 9a, 9b
Cryptocephalus bivittatus
Say, 1824: 440.
Pachybrachys albescens
Suffrian, 1858: 404.
Recognition.
Body very large, primarily yellow (
Habitus 2
); prothorax suffused with rufous; elytral punctation confused, with somewhat apparent rows on disc; elytral color pattern bivittate, with outer vitta rarely entire (
Figure 7e
); pygidium yellow (
Figure
8
a
); male size large: length 3.12
+/-
0.16 mm, width 1.64
+/-
0.05 mm. These characters allow identification of even singleton females.
Distribution.
Pachybrachis bivittatus
is a transcontinental species found across Canada and the United States (
LeSage 1991
;
Riley et al. 2003
). In Ontario, it is most common in the southernmost counties. In
Quebec
, it occurs in the Ottawa Valley and in the St. Lawrence Lowlands. The Saguenay Region is probably its northernmost limit (
Map 2
).
Material examined.
ONTARIO: Carleton Co., Constance Bay, 26.VI.1995, B. F. & J. L. Carr [1♀, CNC]; Elgin Co., New Sarum, 16.VI.1956, W. J. Brown [5♂ 5♀, CNC]; Essex Co., Amherstburg, 6.VI.1936, G. M. Stirrett [2♀, CNC]; Belle River, 26.V.1946, S. D. Hicks [1♂, CNC]; Kingsville, 23.V.1962, Kelyone & Thorpe [1♀, CNC]; same data, except 19.VI.1954, G. B. Wiggins [1♀, ROM]; Pelee Island, 24-27.VI.1935, R. C. Osburn [1♂ 1♀, OSUC]; same data, except 4.VII.1940, W. J. Brown [2♀, CNC]; Point Pelee, 29.VI.1931, W. J. Brown [4♂ 7♀, CNC]; same data, except 1.VI.1933, G. M. Stirrett [3♂, CNC]; same data, except 29.V.1955, S. D. Hicks [3♂ 4♀, CNC]; same data, except 28.VI.1961, Kelton & Brumpton [2♂ 1♀, CNC]; Haldimand Co., Dunnville, 7.VII.1961, W. & W. Plath [1♂, USNM]; same data, except 7.VIII.1961, W. Plath [1♂, USNM]; Kent Co., Thamesville, 15.VI.1930, G. M. Stirrett [1♀, CNC]; Rondeau Park, 5.VI.1985, J. M. Campbell & A. Davies [1♀, CNC]; Lambton Co., Grand Bend, 17.VI.1956, W. J. Brown [1♂ 4♀, CNC]; Lincoln Co., Beamsville, 19.VII.1939, S. D. Hicks [3♂ 3♀, CNC].
QUEBEC
: Argenteuil Co., Carillon, 24.V.1974, E. J. Kiteley [2♂ 1♀, CNC]; Deux-Montagnes Co., La Trappe, 5.VIII.1932, J. Ouellet [1♂, CEUM];
Ile-de-Montreal
Co.,
Montreal
, F. Knab [1♂, USNM]; same data, except 31.V.1941 [1♀, CEUM]; same data, except 15.VI.1961, M. Larochelle [1♂, CEUM]; same data, except 3-14.VII.1969, E. J. Kiteley [4♂ 6♀, CNC]; same data, except 17.VI, J. Ouellet [1♀, USNM]; Nicolet Co.,
Becancour
, 24.VI.1967, J. L.
Laliberte
[1♂, IDM]; Portneuf Co., Neuville, 9.VII.1939, J. Filteau [1♂ 1♀, CEUM]; Sainte-Catherine, 17.VI.1953, J. C.
Aube
[1♂ 7♀, LEM]; same data, except 8.VII.1956 [2♀, LEM];
Quebec
Co., Sainte-Foy, 17.VI.1933, V. Boulet [1♀, CEUM]; Cap-Rouge, 27.VI.1956, J. L.
Laliberte
[2♂ 2♀, IDM]; Saguenay Co.,
Riviere
Deschenes
, 22.VI.1966, A. Franeslier [1♀, CEUM]; Saint-Jean Co., Cantic, 25.VI.1983, on
Salix amygdaloides
Andersson, A. Larochelle [1♂ 3♀, CNC]; Saint- Maurice Co., Pointe-du-Lac, 3.VII.1937 [1♀, CEUM]; Vaudreuil Co., Rigaud, 12.VII.1908, J. Ouellet [1♂, CEUM].
Host plants.
Pachybrachis bivittatus
is typically associated with willows (
Salix
spp.,
Salicaceae
) (
Fall 1915
;
Barney 1984
;
Downie and Arnett 1996
;
Clark et al. 2004
for literature review). In Canada,
MacNay (1958)
reported a light infestation of
Pachybrachis bivittatus
on the foliage of willow along the river banks north of Coaldale, in Alberta. In eastern Canada, LeSage (personal observations) observed it on
Bebb's
willow (
Salix bebbiana
Sarg.), sand-bar willow (
Salix interior
Rowlee), and stalked willow (
Salix petiolaris
J.E. Smith). Larochelle (see above) collected it on the peach-leaved willow (
Salix amygdaloides
Andersson). The larvae feed in the litter, on willow leaves, but only when they are decayed (
LeSage 1985
).
Comments.
With its large size, bivittate elytra, and close association with willows,
Pachybrachis bivittatus
is one of the easiest species to identify.