PAN·PACIFIC ENTOMOLOGIST 72(3): 168-170, (1996) Scientific Note DESCRIPTION OF THE MALE OF CERANISUS

Members of the genus Ceranisus Walker (Eulophidae, subfamily Entedoninae) are solitary, internal parasitoids of immature stages of thrips (Thysanoptera). The Nearctic species of Ceranisus have been recently revised (Triapitsyn, S. V. & D. H. Headrick. 1995. Trans. Am. Entomo!. Soc., 121(4): 227-248). However, this revision lacks a description of the male of Ceranisus americensis (Girault), a common parasitoid of flower thrips, Frankliniella spp., in North America. The importance of C. americensis as a biological control agent against western flower thrips, Frankliniella occidentalis (Pergande) (Greene, 1. & M. Parrella. Green­ house Grower, Dec 1992: 69-72, as Ceranisus sp.), warrants complete taxonomic knowledge of this parasitoid species. Ceranisus americensis, originally described as a Thripoctenus (Girault, A. A. 1917. Proc. U.S. Nat. Mus., 53(2213): 445-450), was known only from females until recently, when Robert Zuparko sent several Ceranisus specimens to us for a possible species identification. This material, collected in California in 1964, contained females of C. americensis along with two males that we consider as being conspecific. Despite sexual dimorphism in some antennal structures com­ mon among Ceranisus spp. (i.e., a swollen scape and a 3-segmented club in males and a slender scape and a 2-segmented club in females), both female and male C. americensis share similar funicular characters: Fl is small and usually lacking sensilla whereas F2 is much larger than Fl and bears several sensilla (Fig. 1).