The Scoliid Wasps Of Florida I. Introduction Biology And Key To Nearctic Genera

The family Scoliidae is composed of fairly large, stout-bodied wasps (fig. 1A, B), often brightly patterned in shades of red and yellow, white, or one of these colors in combination with black. Scoliid wasps are parasitic upon larvae of soil-inhabiting scarab beetles. DeBach (1964) briefly reviewed the literature on these wasps for their use in the biological control of white grubs. The primary emphasis has been with grubs of sugar cane in Hawaii, the Mariana Islands, and Mauritius where control has ranged from “partially” to “completely” successful (DeBach, 1964). In the 1920′ s about 15,000 adults of 2 species of scoliid wasps, Campsomeris annulata Fabricius (=Campsomeriella) and Campsomeris marginella modesta (Smith) (=Micromeriella), were released in the northeastern United States to control the Japanese beetle (Krombein, 1948). Even though these wasps were experimentally shown to parasitize this beetle, they did not become established in the United States (also see review by Fleming, 1968).

The scoliid wasps and related families (e.g., parasitic tiphiids, velvet ants) traditionally form a higher group (superfamily) called the Scolioidea. These wasps combine at least 2 notable features which help place them in an interesting and pivotal position within the Hymenoptera. Firstly, they have the biological characteristics of the more primitive parasitic Hymenoptera, and secondly, they have the morphological characteristics of the more advanced “stinging” wasps. This combination of characters leads most present day hymenopterists to place ancestral scolioid wasps (and the related bethyloid wasps) as the most primitive of the higher bees, wasps, and ants (Evans and Eberhard, 1970; Malyshev, 1968; Iwata, 1976; Spradbery, 1973). Brothers (1975:577-578) disagreed, however, and stated that “it is not appropriate” to consider a member of the Scolioidea as ancestral to the bees, wasps and ants.

The family Scoliidae is represented in America north of Mexico by 20 species (and numerous subspecies) in 5 genera (Krombein, 1951, 1958, 1967; Betrem, 1972). In Florida 3 genera are represented by 8 species. The present circular gives a generalized account of biology and a simplified pictorial key to genera of American Scoliidae north of Mexico. Future circulars will treat the 8 Florida species belonging to the genera Scolia, Trielis, and Campsomeris. The historical treatment of names (i.e., nomenclature) in Scoliidae is quite complicated and is not discussed in this circular but names have been brought to current status by the use of Krombein (1951, 1958, 1967), Betrem (1972), and personal communication with Drs. K. V. Krombein and A. s. Menke (Smithsonian Institution and Systematic Entomology Laboratory, U.S.D.A., United States National Museum, Washington, D.C., respectively).