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24
BULLETIN OF THE UNIVERSITY OF NEBRASKA STATE MUSEUM
record of Silpha opaca, but, again, there
is no voucher specimen. Anderson and Peck
(1985) and Peck and Kaulbars (1987), using
the information in Cooley (1917), included
Nebraska in the distribution of this species.
This species occurs just west of the Rocky
Mountains in Wyoming, Montana, Utah,
and Idaho.
According to Anderson and Peck
(1984), both adults and larvae of Aclypea
bituberosa are phytophagous and eat the
leaves and shoots of native species of Solanaceae
and Chenopodiaceae, introduced
weeds, and at least 12 species of plants of
agricultural or horticultural importance, including
squash, pumpkin, spinach, wheat,
beet, radish, rhubarb, potato, lettuce, cabbage,
rapeseed, and turnip. Occasionally,
this species has been considered a pest of
some of these crops.
Genus HeTeROSIlpHA
Heterosilpha Portevin 1926: 83.
The genus Heterosilpha consists of
two species that are both endemic to North
America. Heterosilpha aenescens (Casey)
occurs near the west coast from southern
Oregon to northern Baja California in
Mexico (Miller and Peck 1979, Peck and
Anderson 1985) and H. ramosa (Say) is
found in most of western North America
from southern Canada to northern Mexico
(Peck and Anderson 1985). Only the latter
species is found in Nebraska.
Prior to Portevin’s (1926) establishment
of the genus Heterosilpha, these species
were included in Silpha, a catch-all
genus at the time. Arnett (1946) suggested
that aenescens was a synonym of ramosa,
but this has not been adopted by subsequent
authors.
Species of Heterosilpha are unique
among North American silphids because of
the presence of three, branching costae on
each elytron. Larvae are characterized by
having the sensory area of the second antennal
segment with numerous small plates
(as in Fig. 42) and the urogomphi subequal
to the tenth abdominal segment.
Heterosilpha ramosa (Say)
(Figs. 21-22, 39, 47-48)
Silpha ramosa Say 1823: 193.
Silpha cervaria Mannerheim 1843: 252.
Diagnosis. Length 11.2-16.7 mm. Thorax:
Color entirely black. Surface finely, densely
punctate. Elytra: Color black. Surface tricostate,
costae with short, lateral branches.
Males with apex rounder, females with apex
slightly elongated and attenuated (Figs. 21-
22). Legs: Males with tarsomeres 1-4 on first
and second pair of legs laterally expanded
and densely pubescent beneath; females
with tarsomeres normal, not expanded.
Distribution. Heterosilpha ramosa is
found west of a line from northeastern
Minnesota to south-central New Mexico;
it also occurs in southern Canada west of
Lake Superior to British Columbia as well
as in northern Baja, California (Anderson
and Peck 1985, Peck and Kaulbars 1987).
In Nebraska, this species is more abundant
in the western half of the state with populations
extending eastward as far as Grand
Island. There are two old Lincoln records
(pre-1920), but this species does not now
occur in Lancaster Co.
locality Records (Fig. 48). 78 Nebraska
specimens examined or recorded.
CHERRY CO. (43): Hackberry Lake, Trout
Lake, Valentine, Valentine Wildlife Refuge;
CUSTER CO. (2): Anselmo, 17 mi. E.
Anselmo; DAWES CO. (1): Pepper Creek;
GARDEN CO. (4): Crescent Lake, Oshkosh;
HALL CO. (2): Alda, Mormon Island Refuge;
KEITH CO. (15): Cedar Point Biological Station;
KEYA PAHA CO. (1): Mills; LINCOLN
CO. (8): Box Elder Canyon, Moran Canyon,
North Platte, Wellfleet; LOGAN CO. (1): No
data; McPHERSON CO. (1): Sandhills Ag
Lab; MORRILL CO. (3): No data; SCOTTS
BLUFF CO. (1): Mitchell.