Pnigalio agraules (Walker) and Pnigalio mediterraneus Ferrière and Delucchi (Hymenoptera: Eulophidae): two closely related valid species

The genus Pnigalio is very difficult to study because of the large intraspecific variability of many traits considered diagnostic. Pnigalio agraules (Walker) and Pnigalio mediterraneus Ferrière and Delucchi were synonymized in 1984 because it was not possible to distinguish them on the basis of morphology. Here we propose the revalidation of P. mediterraneus based on multiple evidence: two molecular markers, cytochrome oxidase subunit I (COI), and the second expansion segment (D2) of the 28S ribosomal subunit (28S-D2), host ranges and the shape of eggs. As the two valid species are potentially important parasitoids for biological control of key pests such as Bactrocera oleae (Rossi) and Cameraria ohridella Deschka and Dimic, practical consequences of the wrong synonymy are also discussed.