Morphological features and molecular phylogeny of Placochela Rubsaamen (Diptera: Cecidomyiidae) with implications for taxonomy and host specificity

Morphological studies, combined with phylogenetic analysis based on partial nuclecitide sequencing of the mitochondrial DNA cytochrome oxidase subunit I region, were used to elucidate the taxonomic status of the genus Placocbela Rubsaamen within the tribe Asphondyliini and of two included species. Placocbela is confirmed as a distinct genus, separated from Schizomyia Kieffer morphologically and phylogenetically, but its two European species are not separable and are therefore synonymized. Illustrated descriptions of adults and larvae of Placocbela nigripes (Low) on two of its known hosts, Sambucus nigra Linnaeus and Ligustrum vulgare Linnaeus, are provided. Polyphagy has been recorded in the subtribe Asphondyliina, but this is the first record of such polyphagy in the subtribe Schizomyiina.