Untangling the Anagyrus pseudococci species complex (Hymenoptera: Encyrtidae), parasitoids of worldwide importance for biological control of mealybugs (Hemiptera: Pseudococcidae): Genetic data corroborates separation of two new, previously misidentified species

Abstract

Endoparasitoid wasps in the genus Anagyrus Howard (Hymenoptera: Encyrtidae) are commonly used in the biological control of mealybugs (Hemiptera: Pseudococcidae) worldwide. During a recent biological control program initiated for management of the pink hibiscus mealybug (PHM), Maconellicoccus hirsutus (Green), by its primary parasitoid Anagyrus kamali Moursi, genomic sequences of the parasitoid were found to be dissimilar with sequences previously published for A. kamali. This discrepancy in the identification of the specimens, which originated in the Imperial Valley, California, USA and Valle de Banderas, Nayarit, Mexico, launched an investigation into the identity of the unknown California/Nayarit population alongside species of the Anagyrus pseudococci complex, in which Anagyrus pseudococci (Girault), Anagyrus sp. near pseudococci, A. kamali, Anagyrus dactylopii (Howard), and Anagyrus kivuensis Compere are informally classified. Morphological evaluation and morphometric analyses provided evidence for the identification of the California/Nayarit population as a new species based on the coloration of the male antennal scape and the ratio of the minimum width of the female frontovertex to the head width. Analyses of mitochondrial and nuclear DNA regions further supported the definition of this population as a distinct species. Along with this new taxon, herein named Anagyrus callidus Triapitsyn, Andreason & Perring sp. n., A. sp. near pseudococci is described and named Anagyrus vladimiri Triapitsyn sp. n. Phylogenetic analysis supported the monophyly of the A. pseudococci complex, originally described based on morphological similarity to A. pseudococci and the coloration of the first funicle segment of female antenna, relative to non-complex Anagyrus species. The effectiveness of A. callidus as a biological control agent against the PHM was demonstrated by the parasitoid’s successful establishment and significant reductions of the pest in the Coachella Valley.