Predaceous Diving Beetle is usually black or dark brown, sometimes with green, bronze, or brown stripes or spots. The body is oval and very hard, and the hind legs are flattened and fringed for swimming.
They are very common in ponds and quiet streams. They swim by moving their hind legs simultaneously like a frog which differentiates them from the similar-looking water scavenger beetles who move their hind legs alternately.
The adults sometimes leave the water at night to fly to other water bodies. While flying they are often attracted to lights. The larvae are sometimes called water tigers. Both the larvae and adults are predaceous and feed on other aquatic arthropods and small aquatic animals including fish.
Found this big guy in Mission BC tonight! Pretty big, about 3cm long; hadn’t ever seen one before.
Discovered one swimming frantically in a 1 litre pot with about 3 inches of water in it – a mystery as I did not know they could fly although that’s pretty obvious if one thinks about it! Obviously attracted to my greenhouse gro-lights and very happy to be released into our large pond
thank you! i unfortunately smushed one of these the other night and it’s been bugging me greatly as to what kind of beetle it was. i really appreciate the info. and sorry to the one i smushed
I encountered one of these last night. About an inch and a half long. Never seen one before being from the Great Lakes Region.