August, 2016

Giant Water Bug

Some insects are too large to ignore and the giant water bug (Lethocerus medius), often over two inches long, is one of them. During wet weather, these aquatic predators are sometimes attracted to lights when they are flying between ponds. They can easily mistake a tiny puddle for a larger pool and I've found them in the gutters of roads, or sometimes just sitting on the pavement under a street light. There are several species in this genus, and they are all enormous.

Being true bugs, these insects have a tube mouth and subsist on a completely liquid diet. They use their probosces to puncture prey, which includes insects, tadpoles and fish, and also to protect themselves from their own predators. Their bite can be painful; one species is called the Eastern Toe Biter.

As expected for an aquatic animal, the rear legs are adapted to swimming and not walking. The wings, however, are well-developed, and the bugs have no trouble moving between temporary water sources. The front legs are raptorial and efficiently capture prey. When the bugs are submerged, they breathe through a tube sticking out of their rear end. This tube can be extended, but it is almost completely withdrawn in the photo shown above.