Trachelus stipa (Hymenoptera: Cephidae), a new stem sawfly from Central Anatolia associated with feather grass (Stipa holosericea, Poaceae).

Trachelus stipa is described from Central Anatolia, Turkey. It is morphologically close to T. flavicornis and T. troglodyta regarding the structure of the preapical sterna of the male. It is unique among Trachelus species regarding the shape of the claw of the posterior leg, the size of the denticles of the ovipositor and the short valvula 3 of the ovipositor sheath in the female, and the distally notched hypopygium in the male. The genetic distance found in two mitochondrial (COI and cyt b) and one nuclear (EF-1α) gene regions support the recognition of this species and its placement within Trachelus, although the shape of the ovipositor sheath disagrees with this concept. Stipa holosericea, the host of T. stipa according to field observations, represents the first record of a feather grass as the host of a sawfly species.

A molecular phylogeny of the Cephinae (Hymenoptera, Cephidae) based on mtDNA COI gene: a test of traditional classification.

Cephinae is traditionally divided into three tribes and about 24 genera based on morphology and host utilization. There has been no study testing the monophyly of taxa under a strict phylogenetic criterion. A molecular phylogeny of Cephinae based on a total of 68 sequences of mtDNA COI gene, representing seven genera of Cephinae, is reconstructed to test the traditional limits and relationships of taxa. Monophyly of the traditional tribes is not supported. Monophyly of the genera are largely supported except for Pachycephus. A few host shift events are suggested based on phylogenetic relationships among taxa. These results indicate that a more robust phylogeny is required for a more plausible conclusion. We also report two species of Cephus for the first time from Turkey.