PROC. ENTOMOL. SOC. WASH. 105(2). 2003. pp. 467-483 STEPHANIDAE (HYMENOPTERA) OF AMERICA NORTH OF MEXICO Alexandre Pires Aguiar and Norman F. Johnson Universidade de Sao Paulo, Museu de Zoologia, Avenida Nazare 481. Ipiranga, Sao Paulo. SP 04263-000. Brazil (e-mail:
[email protected]); (NFJ) Department of Entomol-ogy, The Ohio State University. 1313 Kinnear Road. Columbus. OH 43212-1 192. U.S.A. (e-rnail:
[email protected]) Abstract. — Eight species of the family Stephanidae are found in Canada and the con-tinental United States. Two new species are described. Megischits annectens Aguiar, n.sp., and Megisc/ius brevicaudatus Aguiar, n.sp., from the western U.S.A. Mei;isclnis bicolor Westwood is redescribed, and regional color forms are not recognized as formal subspecies. A key to species is provided. Data on geographical distribution, flight period, and bioloaical associations are summarized. Key Words: Hymenoptera. Stephanidae, Schlettereriiis Ashmead, Megisclms Brulle, new species, Nearctic The family Stephanidae is a basal group of apocritan Hymenoptera that are idiobiont parasitoids of the larvae of wood-boring Coleoptera (Cerambycidae, Buprestidae) and Hymenoptera (Siricidae). The family is fairly small, encompassing only 290 de-scribed species around the world. Our ob-jective here is to discuss the taxonomy of stephanids from the United States and Can-ada, an area last treated by Townes ( 1949). We include a review and update of the spe-cies covered by Townes as well as the de-scription of two new species. The first Nearctic species of stephanid to be described was Megisclms bicolor West-wood (1841). Cresson (1872. 1880) later described two additional species, one of which, Stephanus cinctipes Cresson, was designated as the type species of Schletter-erius Ashmead (Ashmead 1900a). Three species described by Schletterer ( 1889) and Davis (1897) are synonyms of M. bicolor. Townes (1949) described two species and recorded the Cuban species Megisclms brunnens Cresson for the first time in the U.S.A. In total, Townes recognized six Ne-arctic species and divided M. bicolor into two subspecies. Carlson ( 1979) did not rec-ognize of the validity of these subspecies. Material and Methoi5s A total of 833 specimens were studied from North American and European mu-seums. The Mexican fauna of Stephanidae is both more diverse in species, and the spe-cies are more variable in structure and col-or. Therefore we have defeired a consider-ation of the specimens found in Mexico un-til they can be considered in the context of the full diversity of that fauna. Morpholog-ical terminology and generic concepts gen-erally follow Aguiar (1998). Measurements of total length are made from the base of the anterior tubercle on the head to the apex of the abdomen. The ratio of pronotal length to width compares the maximum length to minimum width (Fig. 1). The terms semiannular and preannular refer to differentiated parts of the pronotum (Elliott 1922). The semiannular (Fig. 3, sa) is the
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