April 20th, 2006
predaceous diving beetle
As mentioned yesterday, I found an evening visitor wandering around in the lane beside our van. After shooting some photos, I brought the Predaceous Diving Beetle (Family Dytiscidae) indoors and kept it in a container for the night. This morning, I put it into the small aquarium that I use for photographing aquatic insects (see above and below — click on images to see larger versions). In addition to the photos, I also shot a short movie clip of the beetle swimming around in the aquarium.
As can be seen in the photos, the hind pair of legs are quite long and have brush-like filaments that help to make the legs function more like paddles or oars when the beetle is swimming. The hind legs are quite flexible and curl and bend upwards and downwards, and generally help to the insect maneuver in water. When at rest, the insect floats to the surface and holds its hind legs out directly to the sides like stabilizers. It’s really quite an active insect and can swim quite rapidly when not restrained in a small aquarium.
