
Great diving beetle (female) and common water strider
This is the first time I've seen a diving beetle. Unfortunately, this one is dead, which I learned after flipping it over. Because of the ridged shield, this likely is a female. They are quite aggressive and capable predators, both as larvae and as adults. What amazes me most is that they can still fly, I did not expect that.

The great diving beetle, Dytiscus marginalis, is a large aquatic diving beetle native to Europe and northern Asia, and is particularly common in England. The great diving beetle, true to its name, is a rather sizable insect. The larvae can grow up to 60 millimetres (2.4 in) in length, while the adults are generally between 27–35 millimetres.