What species of insect help to control the numbers of their fellows during the summer? This has been debated for some time, but a clear answer has remained elusive, as it has been difficult to monitor the numbers consumed by different insect predators. Now this new study sheds light on the role of damselflies that occur in large numbers, even in suburban gardens around ponds, and reveals some interesting answers.
Researchers based at the University of Turku in Finland have found that the matchstick-sized but fiercely predatory damselflies catch and eat hundreds of thousands of insects over a summer - in an area surrounding just a single pond. In terms of weight, this equates to a total prey mass of just under a kilo (2.2lb). These aerial hunters mostly catch different kinds of midges (chironomids), but also take large numbers of other insects.
Common blue damselfly.