1573 



Superfamily SPHECOIDEA 



By Karl V. Krombein 



For nearly a century most specialists in this group, influenced by Kohl's ultra-conservative 

 views, considered that the superfamily contained a single family, the Sphecidae. The monumen- 

 tal generic reclassification by Bohart and Menke (1976) embraces this opinion. However, 

 Brothers (1975) demonstrates convincingly that each of the aculeate superfamilies should com- 

 prise several families if the family-level groups are to represent categories of equal phylogenetic 

 value. The classification used elsewhere in this catalog supports the latter conviction. Ac- 

 cordingly the major subfamilies recognized by Bohart and Menke are restored to family rank, a 

 position accorded them by most specialists of the previous century. 



Some authors believe that the sphecoid wasps and the bees belong to a single superfamily, the 

 Sphecoidea. For example, Brothers divides the Sphecoidea into two informal groups, the 

 Spheciformes and Apiformes, with eight and nine famiHes respectively. However, on the basis of 

 the presence or absence of a hind tibial strigil, Boerner (1919) divides the Aculeata into two sub- 

 sections, the sphecoids, pompiloids and vespoids, and the formicoids, scolioids and apoids. The 

 phylogeny of the sphecoid wasps and bees requires more intensive investigation than they have 

 had hitherto, for the possibility exists that the bees may not be so closely related to the sphecoid 

 wasps as supposed by some workers. At this time the Sphecoidea and Apoidea are maintained as 

 separate superfamiHes. 



The behavior and Hfe history of this diverse assemblage of wasps has attracted a host of ob- 

 servers both in the United States and abroad. Many species are ground nesters and are known 

 popularly as digger wasps; most of them dig their own nests but some species appropriate 

 pre-existing burrows of other arthropods and modify them as needed. Numerous species nest 

 above ground in pre-existing cavities such as abandoned borings of beetle larvae in wood, old in- 

 sect galls and old mud-dauber nests; many of these species can be induced to nest in borings in 

 wood called trap-nests. Some of our species excavate their own nests in soft pith of shrubs such 

 as sumac and elderberry, or in rotten wood. Relatively few North American species are mason 

 wasps, building various kinds of mud cells. Several genera are cleptoparasites of other 

 ground-nesting sphecoids. So far as known the North American species are all solitary wasps, 

 but apparent eusociality has been discovered in the Jvleotropical genus Microstigynus Ducke. 



Members of the Sphecoidea prey upon a great variety of terrestrial insect orders as well as 

 upon spiders. Varying degrees of host specificity are found among the several families and 

 lesser categories. In general the more primitive sphecoids prey upon the more primitive and an- 

 cient groups of Hemimetabola while the more advanced groups prey upon the higher groups of 

 Holometabola. 



The pre- 1920 references listed below under the side-head Taxonomy are not reliable for 

 generic or specific discrimination. 



Revision: Bohart and Menke, 1976. Sphecid wasps of world, 695 pp., 190 figs, (reclassification 

 of world genera, lists of species-level taxa). 



