Explanation of Names
Rhyssa Gravenhorst 1829
Greek ῥυσός, ῥυσσός 'wrinkled'
Numbers
7 spp. in our area, ~20 total
1. Rhyssa alaskensis: western (AK―CA―NM)
2. Rhyssa crevieri: eastern (NS―NC to MN)
3. Rhyssa hoferi: western (CO―NM―AZ)
4. Rhyssa howdenorum: eastern (MD―GA―AL)
5. Rhyssa lineolata: eastern, northwestern (BC―NS―GA)
6. Rhyssa persuasoria: transcontinental (BC―CA to NF―GA)
7. Rhyssa ponderosae: southwestern (CA)
Identification
Overview of Genus
Separated from other members of its family by the larger size, presence of a median tooth on the clypeus, lack of any fusing of the first sternite and tergite, general black-white-orange coloration, and white markings on the first four segments of the abdomen.
(1)
Rhyssella spp. are superficially similar in coloration but lack a median tooth on the clypeus and have no fusing of the first sternite and tergite. In photography,
Rhyssella can be eliminated by their smaller size and lesser to no white markings on the first four segments of the abdomen.
(2)
Overview of Species
Our species are separated as follows:
(2)
Western Species
R. alaskensis: the only species with the posterior orbits entirely black; antennae entirely black; abdomen with prominent white spots
(1)
R. hoferi: the only species with a strongly ferruginous coloration and dark wings; antennae with a yellow band; abdomen marked with narrow white bands
(1)
R. lineolata: the only western species with antennae with a white band; abdomen with white spots
R. ponderosae: antennae entirely black; abdomen with reduced whits spots; hind coxae entirely black
(3)
R. persuasoria: antennae entirely black; abdomen marked with white spots; hind coxae largely orange
Eastern species
R. lineolata: antennae with a white band; abdomen marked with white spots; hind coxa with a white spot;
metapleuron with a larger, square-to-rounded white spot
R. crevieri: antennae with a white band; abdomen with white spots; hind coxa entirely dark; metapleuron with a smaller, notched to subtriangular white spot
R. howdenorum: antennae entirely black; abdomen with narrow white bands
R. persuasoria: antennae entirely black; abdomen with white spots
Remarks
Females drill into dead wood to oviposit on horntails in the subfamily Siricinae.
