Thread subject: :: Chironomidae v Ceratopogonidae

Posted by John Carr on 17-11-2022 19:45

If the postnotum has a longitudinal groove, it is Chironomidae. This is rarely absent and you are unlikely to collect the exceptions in central France. On marine shores you may find them.

If vein M is forked or there is a crossvein between the branches of the radial vein, it is Ceratopogonidae. The veins can be hard to make out in photographs.

If the front basitarsus is longer than the front tibia it is Chironominae. There is a slight amount of overlap in "leg ratio" with Orthocladiinae.

If the last 4-5 antennal segments are elongated, it is Ceratopogonidae. If only the last 1 or 2 are, Chironomidae. If the antenna is reduced to 9 or fewer flagellomeres, Chironomidae.

If the claws are long, a femur greatly swollen, or there are spines under the fifth tarsomeres, one of the predatory Ceratopogoninae. Likewise if it has apparently functional mandibles (in Europe).

Usually if the hind legs are long you have Ceratopogonidae, but see also Tanypus in the Chironomidae.