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 SCOLIID
WASP
Campsomeris pilipes
Family Scoliidae - Scoliid Wasps
Order Hymenoptera - Bees, Wasps and relatives
Risk Status
Official status
Information not available at this time.
Image Credits: Scoliid Wasp sketch by Hannah
Nadel in 'Rare Invertebrates of the South Okanagan' brochure
Distinguishing features
The Scoliid or Scarab-hunter Wasps, being huge, grey and yellow wasps,
are easily mistaken for yellow-jacket wasps (paper wasps). Unlike these
species however, they lack the yellow marks on their head and thorax.
Campsomeris pilipes is a large, hairy, robust wasp, (26-30
mm) long. Males differ from male velvet-ants in being larger, less
hairy, and darker in colour. Their head, antennae, thorax, and legs
are jet-black. The abdomen is largely yellow with black banding.
Unlike the wingless velvet-ant females, scoliid females are winged.
In both sexes the dark wing membrane beyond the closed cells has many
lengthwise wrinkles near the outer margin.
Distribution
Map
Red dots indicate specimen records or confirmed breeding sites.
British Columbia
Campsomeris pilipes is known only from Chopaka in the lower
Similkameen Valley and the sandy benchlands east and north of Osoyoos
Lake, where much of their habitat was destroyed by fire in 1993.
North America
Campsomeris pilipes ranges from Colorado west to Oregon and
California and south to Texas and Mexico.
Habitat
They can be seen hovering low over sandy soil in grasslands and
forest edges, where the females seek out the burrowing larvae of
scarab beetles. In British Columbia, Campsomeris pilipes
lives in sandy grasslands where sagebrush and antelope-brush grow.
Why is it endangered?
Rare invertebrates of the south Okanagan and Similkameen valleys are
threatened not by direct exploitation, but by loss or degradation of their
habitats. They are at risk because their ecosystems are at risk.
The grasslands of the southern interior of the province are a valuable
agricultural resource, and their rich soils have been ploughed and irrigated
to produce tree fruits, grapes, and vegetables. Pesticide use has probably
had a great impact on native insects living in around agricultural areas.
As well, heavy grazing has altered the plant composition of grasslands,
changing the invertebrate communities.
The massive diversity of invertebrate species in British Columbia makes
it very difficult for entomologists to do a literature or collection survey
to determine which species are endangered or threatened. Specialized,
detailed surveys will be required for almost every species that is suspected
of being endangered. Despite a general ignorance about invertebrate distribution,
information is known about a number of species that are confined to threatened
habitats of very limited extent in the Thompson-Okanagan valleys.
Biology
Scoliid wasp larvae are external parasites
of the larvae of scarab beetles. This gives the family its common name,
Scarab-hunter Wasps. The female of Campsomeris pilipes burrows
in soil or wood debris in search of beetle larvae. When it finds a larva,
the wasp stings and paralyzes it. She then digs around it, forming a small
chamber. The wasp then deposits an egg on the host. The wasp larvae feed
on the beetle larva and then pupate in the cell-like chamber.
If disturbed, females can sting painfully.
Adult Scoliid Wasps visit flowers and feed on nectar.
Sources for more information
Related On-line Sites to Visit
Publications
Rare Inverts of the South Okanagan, brochure, MOE, 1995
The Audubon Society Field Guide, p. 820
Museum Specimens
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