Ten male and II female Graphoderus manitobensis were collected in April and May, 1980 and 1981 from a pond 16 kIn west of Madison, WI. Females can be distinguished from female G. fascicollis (Harris) by their much narrower metastemal wings and more pronounced conugated sculpturing on the pronotum. The SCUlpturing and markings on the pronorum. width of the metastemal wings, and projections at the base of the ovipositer are used to identify females of G. manitobensis and three closely related species.
Tracy, Byrn H. and Hilsenhoff, William L.
"The Female of Graphoderus Manitobensis With Notes on Identification of Female Graphoderus (Coleoptera: Dytiscidae),"
The Great Lakes Entomologist: Vol. 15
, Article 4.
Available at: http://scholar.valpo.edu/tgle/vol15/iss3/4