The common blue mud-dauber of the United States and Canada is generally known as either Chalybion caeruleum Linnaeus or Chalybion cyaneum Fabricius (or Klug or Dahlbom). Both names are incorrect. This wasp was first described as Sphex caerulea by Johansson or Linnaeus in 1763 (Amoenitates Academicae, VI, p. 412).

A list of the host plants and parasites of lepidopterous larvae reared during a study of the native hosts of parasites of the oriental fruit moth, Grapholitha molesta Busck, was published in 1935. Much additional data which have since accumulated appear worth placing on record, particularly the host relations of the parasites.

Venation as in Meyrick's figure (Handbook Brit. Lep. 712) except that on primaries vein 9 is connate with the stalk of 6-8 from apex of cell. Unicolorous light ochre-yellow. Head and palpi somewhat paler than forewings. Antennae faintly smoky with traces of brown annulations. In well marked specimens the forewings show the merest traces of irregular, whitish, median and subterminal bands. Secondaries pale smoky. Fringes on both wings light yellowish. Abdomen yellowish, including anal tuft. Traces of smoky shadings on pectus and basal portions of legs. Expanse 9-10 mm.

Although larvae of the five species described below are among those loopers most frequently encountered in numbers, complete data on their life histories are still lacking. The following notes, based on large samples of larvae collected and bred in New England during the past three years, are intended to supplement the accounts of earlier authors and are not in themselves complete.

In 1925 Cushman (Jl. Wash. Acad. Sci., XV, 392) transferred Meniscus mirabilis Cress. to the genus Asphragis, and synonymized with it Asphragis pulcherrimus Ashm., Clistopyga pleuralis Ashm. and Meniscus ostentator Davis. Up to the present this species has constituted the only representative of the genus reported from the United States and Canada.