This is the male, showing flat, broad abdomen with blue pruinosity. The female, broad abdomen with yellow to brown pruinosity. The flight period is from April to September but are mostly seen in May and June. Their flight is very fast as they dart and dive above the water. They are very territorial and will fight with rival males and any other dragonflies they happen to encounter. They characteristically return to a favoured perch, in the sun. When a female enters a male's territory the male will fly up and grab the female. Mating occurs on the wing and the pair are in tandem for only a brief period, often less than a minute. The pair separate and the female will find a suitable location for ovipositing, usually a stretch of open water with submerged vegetation. The female oviposits in flight, hovering above the water and dipping the tip of her abdomen in. The eggs hatch in 4 or 5 weeks and the larvae take one to two years to develop. The larvae live in the silt and detritus at the bottom of the pond, lying buried in mud with just the head and eyes showing. After emergence the adults move away from water and undergo a period of maturation which lasts 10 to 14 days.