The Saucer bug

GOOD CHANCE YOU FIND A FEW OF THIS BUGS in your scoop net after one single stroke, especially when the water is covered with duckweed. They are slightly less common than the Lesser water boatmen and backswimmers, but some pools are teeming with them. Not that you see them right away: saucer bugs are shy and hide in the plants. Yet, as the name suggests, they can swim very well. When they go through the water with rapidly rowing hind legs, they look like water beetles, with their dark upper side and a silvery air layer on their abdomen. But they are true bugs . The Saucer bug can walk well on dry land, and in a scoop net it quickly crawls over the mesh into a corner, or a clump of scooped up plants. This bug needs some supporting vegetation in the water, because though the insect is able to refresh it's air supply by bringing the tip of the abdomen to the surface, like a diving beetle, the Saucer bug cannot keep a stable 'hanging' position there, as those beetles can. That is why the insect dangles helplessly in a glass jar on the water surface, after having swum around in circles frantically for a while. Add some plants or sticks, so it feels more at ease. Even better is a (small) aquarium with bottom and plants.If it does not crawl away into the plants there, Ilyocoris presses itself shyly against the bottom. Now we can take a closer look.

APPEARANCE Seen from above the shape is ovoid, but in side view the body is rather flat, like that of many bugs. Many people feel an innate aversion to flat insects. If we can overcome that, we find this bug is beautifully adapted to its life habits. The underside has a layer of short hairs which hold which hold an air bubble under water. This air layer, which renders a silvery sheen to the abdomen, is part of the breathing air supply for the insect - though some investigators think it's just there for a hydrostatic balance, a bit like the swim bladder of a fish. There's another supply of air: the space between the elytra and the abdomen. The hind legs are provided with wide fringes of hair, forming powerful paddles. The head is streamlined with a flowing, round shape. The eyes seem to give the animal an aggressive expression. )² Furthermore, the strange forelegs are striking, which look a bit like lobster claws. The femur ("thigh") is broadened by the powerful muscles within and has a groove. The fused tibia (shin bone) and tarsus (foot) form a kind of claw, which can be pressed forcefully into the groove of the thigh bone. The grim purpose of this construction will be clear: anything that ends up in those sharp claws will never come out alive again. The forelegs look a bit like the murderous sucking jaws of the larva of the great diving beetle. The claws of the Saucer bug are not hollow however, and not used for sucking out it's prey. Instead it stabs its razor sharp beak in them, then toxic digestive saliva is injected in the wound, after which the dissolved body parts are sucked in. This process is continuously repeated during the feeding process. In a human finger this toxic injection needle may also penetrate deep. Many investigators felt it was worse than the sting of a wasp, yet others wrote that the pain is intense, but short.
Under the elytra, the outer wings or front wings, all Saucer bugs have hind wings of normal length. Whether they are able to fly is not certain. The wings may also have a function in sealing the airspace between the elytra and the abdomen. In spring the males seem to be able to produce tones with there abdomen. After mating, during which the male sits in a slanted left position on the female, the eggs are injected in water plants. That makes them difficult to find.

THE NYMPH As with all Hemipterae (bugs) the nymph already closely resembles the perfect insect. It has no wings and is rather transparent. The bright red eyes, contrasting with the light green body make it look a bit more attractive. Of course is it as predatory as the adult Saucer bug. Yet I've never seen one catch a suitable prey, even if it was right under there beak. Could it be they only hunt in the dark? They are rather vulnerable as well: in the aquarium they often died after a few days, even though there was plenty of food. The nymphs are flatter and more transparent then the full grown Saucer bug. On the picture on the right you can see the transparent carapace. By clicking on that picture you will not only get an enlargement but also see some more pictures of a nymph.