Sawflies belonging to the genus Tenthredo are all rather big, elongated animals. They are very similar to the members of some other genera, such as Tenthredopsis and Rhogogaster. Most of these animals are black, black with yellow or green or entirely yellow or green. Experts can tell the members of the genera Rhogogaster and Tenthredo apart, by looking at the position of the eyes. Tenthredopsis species have longer antennae compared to the others. Tenthredo mesomela is a very common species over most of Britain. The name is very often spelled Tenthredo mesomelas. Both names have a similar number of hits using Google. We use Tenthredo mesomela for that's how it is written in the official name list of animals in the Netherlands.
Tenthredo mesemola is a big species, composed of two colours only: black and green. The upper side is black, except for some spots near head and neck and the shield. Even the upper side of the legs are black. On the front legs this often is less apparent, as the line of black is very thin indeed. The underside of the animal is green entirely. The larvae are found on various plants, Salix species in particular. The adults are often seen eating nectar and pollen on white flowers. But the adults also hunt for small flies which they suck on. This is remarkable for a Sawfly species, for almost all are strict vegetarians.