The first New World representative of Chorosoma (Heteroptera: Rhopalidae): A contribution in honor of Michail Josifov

Except for one Ethiopian species (Linnavuori 1976), Chorosoma until now has been a Palearctic genus (Dolling 2006). Recently, a new species has been discovered in the northwestern United States; we shall name this species Chorosoma josifovi in honor of the 70th birthday of Michail Josifov, who described C. gracile (1968) among his many other excellent contributions to our knowledge of Heteroptera. The new species resembles the widespread C. schillingi in some features, and other species in some other features. No species of Chorosoma appears to have been recorded from far-northeastern Russia (near Beringia) (Martynov l975, Vinokurov 1988), and we plan to work out the biogeographic relationships of the new species. The new species has been collected in arid to desert regions of Nevada, Oregon, and Idaho, and feeds on grasses characteristic of these habitats (e.g., Oryzopsis hymenoides (Roemer & Schultes) Ricker). Thus the new species is similar to the Palearctic species of Chorosoma with respect to type of habitat and type of host plant (see Read 1985, Martynova 1975). The species of Chorosoma are closely related. Hsiao (1963), Martynova (1975), and Putshkov (1986) all suggested that C. brevicolle Hsiao resembles C. macilentum Stål and may in fact be synonymous with it. Josifov (1968) noted the similarity of the male genitalia of Chorosoma longicolle Reuter and those of C. macilentum. And Linnavuori (1976) wrote that his species, C. xenocles Linnavuori, closely resembles C. schillingii (Schilling). As part of our biogeographic analysis, we shall also consider the phylogenetic relationships among the species of Chorosoma.