Water Tiger Dytiscus marginalis
Even in small ponds you can find Diving Beetles. Some people wonder how they got there. Well, the Diving Beetles can do more than just dive: they can fly as well. So they can take many opportunities to explore new wells, ponds and streams. They are among the biggest beetles in the Benelux area: up to 4 centimeters in length! They swim using their back legs. The front and middle legs are used to cling to plants in the water or to grab a prey. One of the best known water beetles in both Europe and America is this Water Tiger. The pictures are of a lonely male strolling through our garden on a windy and rainy March evening. We took it inside for a moment where it served as a patient model. You can tell the males apart from the females by the strange discs on the front legs. These are sucking discs, which are used to get a hold of the fast swimming females during copulation. The Water Tiger is a big animal. The one in the pictures below was almost 38 mm! The adults are long lived and sometimes can be up to 5 years of age. In the moderate zones of Europe this is probably the species that lives longest, once being adult. The larvae live in the water exclusively and my be up to 60 mm long. Both adults and larvae are formidable hunters. Usually the larvae will attack any pray that is not much bigger than they are themselves. Adults really don't care and will attack even fish well over one meter long and bite a piece out of it, usually near the back. They may be harmful in ponds, for even though their bite will not kill bigger fish, through the wound sickness and disease may enter, causing the fish to decease in the end. The adults are capable of biting people painfully. Larvae might bite people as well, but their jaws are rarely powerful enough to go through the skin. Better not experiment with this, for should a larva get through your skin the bite is extremely painful. The larva starts to injects its digestive acid immediately, making the wound even more painful and causing it to heal extremely slowly at the same time.
