Explanation of Names
Monobia quadridens (Linnaeus 1763)
Forewing: ♂ 11.0–14.5 mm, ♀ 14–18 mm(1)
A single, broad, apical fascia on tergum 1 but otherwise black metasoma.
e US & so. ON west to WI-KS-NM(1)
Adult takes nectar at flowers. Larvae feed on caterpillars of Pyralidae (Phycitinae, Epipaschiinae), Crambidae (Pyraustinae), Elachistidae (Stenomatinae), Amphisbatidae, Gelechiidae and Tortricidae.
Usually nests in wood borings, but sometimes burrows in dirt banks. Sometimes takes over abandoned nests of carpenter bees or ground bees, also Sceliphron (mud dauber) cells. Nest is provisioned with caterpillars, and cells of nest are separated by mud partitions.
Euodynerus bidens is similar but less common and has ivory spots behind the eyes: