Explanation of Names
from "rhopalon" (club) + "soma" (body); refers to the club-shaped body
Numbers
3 species in 3 genera in North America listed at
nearctica.com
38 described species worldwide in 4 extant genera and 1 fossil genus
Range
in North America, found primarily in the southeastern states, west to Texas; one species (
Olixus banksii) occurs north to Indiana, and has been reported from Minnesota and Canada (see
PDF doc for distribution of world species)
a primarily tropical family: also represented in Central and South America, Africa, Australia, and Southeast Asia
Habitat
Various, wherever hosts are found (see Food).
Season
Generally found during the summer months.
Food
Larvae of some species in at least two genera are ectoparasitoids of crickets.
It is not known whether adults feed.
Life Cycle
Little is known about this family, as it is rarely encountered. Individuals have enlarged ocelli and are probably active at night, when their hosts (crickets) are active.
See Also
Olixon banksii may be mistaken for a
velvet ant or
Bethylid wasp
Rhopalosoma nearcticum occasionally comes to lights and is very similar to
Ophionine Ichneumonids, but the abdomen is rounded and not as compressed, and the wing venation of each is distinctive.
Print References
Townes, Henry K. 1977. A revision of the Rhopalosomatidae. Contributions of the American Entomological Institute. 15:1 (34 pp.)
Internet References
pinned adult images of Olixon banksii (hymatol.org, hosted at U. of Kentucky by Michael Sharkey
et al)
Rhopalosomatidae of Mississippi a good reference with notes and drawings of all three species found in North America (Mississippi State U.)
Systematics of... Rhopalosomatidae; PDF doc a Master's thesis that includes discussion of taxonomy, descriptions, line drawings, biology, distribution of world species, keys to genera and species (Antonia Guidotti, U. of Toronto, collectionscanada.ca)
presence of Olixon banksii in Minnesota; list [reported from the state but no specimens are present in U. of Minnesota collection] (Insects of Cedar Creek, U. of Minnesota)
