small (less than 5 cm across) white, delicate butterfly. Was moving too fast to capture an image.
Following pond dipping at this pond, an outdoor aquarium was set up with tadpoles and various insects. Greater Waterboatman formed part of the original pond dip but the specimen shown may have been a later spontaneous arrival to the tank, as a dead waterboatman was found suggesting competition over the small tank and its contents - greater waterboatmen (backswimmers in US) being predators of tadpoles and other pond life. The second photo shows what I believe to be an exoskeleton, shed during growth and collected from the aquarium surface.