Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Genus Chlorion

Blue hunting wasp - Chlorion Chlorion cyaneum, Roach Hunter - Chlorion cyaneum - female Big black wasp - Chlorion aerarium Chalybion californicum? - Chlorion aerarium Large, long blue wasp - Chlorion aerarium Blue Spider Wasp - Chlorion aerarium - female Thread-Waisted Wasp - Chlorion aerarium Chlorion? - Chlorion
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon (Aculeata - Ants, Bees and Stinging Wasps)
No Taxon (Apoid Wasps (Apoidea)- traditional Sphecidae)
Family Sphecidae (Thread-waisted Wasps)
Subfamily Chloriontinae
Genus Chlorion
Explanation of Names
Chlorion Latreille, 1802
Numbers
2 spp. in our area(1) and 20 spp. worldwide(2)
Identification
the only member of the genus that dig their own nests, Chlorion aerarium is most common in loose gravelly or sandy soil, and is not as attached to human habitations as the two common mud daubers C. californicum and Scelifron caementarium.
Differs from the superficially similar Chalybion as follows:
Tarsal rake (females only)
Head and thorax sparsely hairy
Propodeum with U-shaped dorsal enclosure defined at least posteriorly by a semicircular sulcus/furrow (Chalybion has at most a median sulcus or pit)
generally larger
the head is more produced at the temples and vertex (different head shape)

...Note greenish or purplish color of many Chlorion vs. blue in Chalybion. The shape of the pronotoum is more strongly notched in Chalybion; ...the head of Chlorion is broader.
Food
C. aerarium preys on crickets, C. cyaneum on cockroaches