My ponds have wet soil edges, I never gave it a thought that this one might not
SNH has this to say about them….
2.2 Life history
The eggs are laid in wet soil in boggy flushes, mires and in the transition zone at the edge of bogs. The larvae are narrow and worm-like with a distinct head, and they live in the soil. They are omnivorous and their diet includes small animals such as nematodes, other insect larvae, fungi and parts of plants. The larvae are semi-aquatic; they drown in open water and desiccate in dry soil. In suitable habitat the larvae can be found in densities of up to about 700 per square metre. The density of larvae can vary markedly over short distances depending upon the water content of the soil.
The larvae develop slowly when compared to some other species in the genus - possibly because of the nutrient-poor soil. The larvae
over-winter in their final instar and pupate in the spring.
In Scotland the adult midges begin to emerge in April and they are active on the wing until October. Within this period there are often two peaks in emergence, one in late May/early June and the second in late July/early August. There are several theories about why there are two peaks in emergence. There could be more than one generation in a year, more than one cohort in the population or climatic factors such as dry periods in the previous summer may be responsible. There is no firm evidence to distinguish between these theories, but C. impunctatus breeds in nutrient poor soil and is unlikely to develop fast enough for two generations in a year. In addition several studies have only found one peak in emergence so the pattern may not be fixed.