Water Wildlife

      GREAT DIVING BEETLE

 

There are various beetles that are carnivorous by nature, certainly all within the Dytiscus family, but none are more potentially harmful than the Great Diving Beetle, or Dytiscus marginalis.  The yellow and black colouring of the diving beetle is a warning, as it so often is in nature. Strong and fierce, it will attack and kill tadpoles, minnows, young fish, and other pond life.  If it grows to it's full size of up to 4 cm, or 1.5 inches, then good sized fish - and certainly the majority of wildlife - will be in peril.  The larvae  are equally ferocious, and will attack tadpoles and similarly sized creatures with ease for the year that they are in that stage of life.  Prey is seized with powerful jaws, and injected with digestive juices - escape is rare.  The immature larvae leave the water to pupate in damp areas around the pond. 

They are easily introduced in to the pond in ignorance.  The eggs are laid among chewed leaves of water plants, and can easily lurk in newly introduced specimens.  Small larva can also be added to the pond accidentally.   Obviously, if new plants can be kept in a large bucket for a couple of weeks, there is more chance of eggs hatching and larvae being seen and removed, but this isn't always possible.  However much care is taken, it might be to no avail anyway, as the adult beetle is capable of flight - although it seems that it generally only does so if forced to search for water which holds more food.

Wildlife they might be - but exclude them if you can from your pond if you would like to see other life in your water!