Morphological, biological, and molecular comparisons among the different geographical populations of Anagyrus pseudococci (Hymenoptera: Encyrtidae), parasitoids of Planococcus spp. (Hemiptera: Pseudococcidae), with notes on Anagyrus dactylopii

Anagyrus pseudococci (Girault) (Hymenoptera: Encyrtidae) is a well-known primary parasitoid of Planococcus spp. and Pseudococcus spp. (Hemiptera: Sternorrhyncha: Pseudococcidae) and as such has been used in biological control in many countries. In the course of a “classical” biological control project against the vine mealybug, Planococcus ficus (Signoret), in California, USA, cultures of A. pseudococci of different origin were established at the University of California, Riverside quarantine laboratory, from the populations in Argentina, Israel, Italy (Sicily), Spain, Turkmenistan, and USA (Coachella Valley, California). Morphological and molecular studies as well as cross-breeding experiments revealed that the Argentine population (first funicle segment of the female antenna partially black, partially white) is reproductively incompatible with and genetically different from all other populations tested (first funicle segment of the female antenna entirely black), which cross-bred freely among each other and group together genetically. The type series and also several freshly collected specimens of A. pseudococci (from Sicily, Italy) are morphologically identical to and not genetically different from the specimens from Argentina. The latter thus apparently represent A. pseudococci, which might have been unintentionally introduced there long ago with grape seedlings from Italy. The other form (called here Anagyrus sp. near pseudococci), which was established in California from previous introductions, thus belongs to a different, currently unnamed species that coexists in Sicily with A. pseudococci and is common in the Mediterranean region. Also discussed is the taxonomic and molecular relationship of these two forms to another species, the Oriental A. dactylopii (Howard), which is morphologically very similar to Anagyrus. sp. near pseudococci.