DIPTERA > NEMATOCERA | Lower Diptera

CULICOMORPHA > Chironomoidea > Ceratopogonidae (173 species)

(subfamilies: Ceratopogoninae and Forcipomyiinae)

A family of mainly tiny midges with non-biting males that can be distinguished by their long-haired antennae and generally slimmer abdomen, and females that typically have a much more rounded shape and virtually bare antennae. Whereas the females of some genera, notably Culicodes, suck blood and have an irritating bite, the males only feed on nectar and are harmless. Ceratopogonids are superficially similar to chironomid non-biting midges, but stouter with shorter legs, broader wings and a more developed proboscis. They also rest with their wings folded back to overlap over their abdomen, rather than partially held up at a tent-like angle, and usually adopt a position where they can naturally use all their legs to support themselves unlike chironomids that typically have their legs spread out with the long fore legs pointing forward.

Most species develop in moist or various aquatic habitats, which range from damp rotting vegetation, dung and fungi, to rot holes in trees, bogs, water margins or actually in rivers and deep lakes. The adults tend to be found relatively close to the larval breeding areas.   

In general terms, family characteristics are described as minute to small (1-5mm), mostly dark-coloured midges that are slender to moderately robust in shape; postnotum without a longitudinal groove; ocelli absent; compound eyes that meet, or almost meet on top of the head; antennae with 13-15 segments, which in most males are plumose; mouthparts well-developed and in the females adapted for piercing; wings are usually clear, although in some species with a pattern and are, on average, broader than those of Chironomidae species; the median vein usually divides into M1 and M2, but the fork is sometimes indistinct.

The British species are now separated into two subfamilies, Ceratopogoninae which is split down into six tribes, and the Forcipomyiinae comprising two tribes including Dasyheleini, which was formerly regarded as another subfamily. Ceratopogoninae is the largest division with 177 species in 17 genera; Culicodes being the largest genus with 47 species divided into various subgenera. The Forcipomyiinae subfamily includes 56 species in just three genera; Dasyhelea with 14 species, and Atrichopogon and Forcipomyia with 13 and 29 species respectively.

Identification to species is impossible without microscopic examination and, in that respect, I thought it would be interesting to check the current records on the NBN Atlas database. At the time of updating this page there were just over 20,600 listed observations, but nearly half were only confirmed at family level. There were then a fair number of entries for the Culicodes and Forcipomyia genera, but with the species undetermined, followed by various specific records that were mainly submitted by the NHM or Natural Resources Wales. In fact, the majority of records were from South Wales and Scotland, with very few from my general area.  

I think, but cannot be certain, that the individuals I managed to photograph in the New Forest on moss-covered deadwood were Forcipomyia sp. I have no idea of the actual species, but the general form, colour, hairiness and the distinctive, but not unique, feathered shape of the male antennae suggest this genus. The eyes are large, the thorax convex and scattered with numerous long hairs, the wings are fringed and covered with flat-laying macrotrichia, and the abdomen is dark with the tergites having pale back edges. The second radial cell should be short and round-ended and the antennae should have 13 flagellomeres, but those two features can't be verified from these photos. I also picked up from my research that the male has narrower wings than the female, and that can be seen when comparing the sexes, although apart from photographing the female, which was on leaf-litter, at the same time, there is nothing to confirm it's the same species. As a point of interest, some members of this genus feed on other insects such as lacewings and dragonflies piecing them through their wing veins.

I'd like to think that over time I can slowly add more information, but for now at least I have a couple of reasonably good photos to represent the family.

Updated, Dec.24 (v.2)