They grab, they stab, they make great dads! - giant water bugs

Ranger Rick, April, 1994 by Anna Mearns

Giant water bugs really do get to be giants - for bugs, anyway. Some kinds that live in tropical ponds, lakes, and streams are as long as four inches (10 cm). The North American bugs shown here are about 1 1/2 inches (4 cm) long.

But that's not the neatest thing about water bugs. Take a look at the back of the male on page 11. It's covered with eggs! Now, isn't that weird? Read on to find out what happened.

CHILD SUPPORT

Most female giant water bugs lay their eggs on water plants. But some kinds go to the males for "child support."

First, the male and female mate. Then the female uses her clawed front legs to grab the male. (She needs to hold tight, or the male may squirm away.) Next, she coats his back with a kind of glue. After that, she'll lay 100 or more eggs on his back. When she's finished, she finds another male or two to carry the rest of her eggs.

Once a male is stuck with the eggs, he acts like a good dad - sort of. He uses his hairy back legs to push water over the eggs. That gives the eggs more oxygen.

But the flowing water sometimes knocks off some of the eggs. Then the male eats them. (They would die anyway, so why let them go to waste?)

Finally, the eggs hatch. Out pop the pale yellow larvae (young). They look a lot like tiny adults. If you check one out closely, you can even see its eyes and sharp beak.

BABY BUGS GROW UP

Like giant water bug adults, the larvae spend a lot of time hanging out just under the surface of the water. There they stick their rear ends out of the water and into the air. Why? So they can breathe!

The larvae have little tubes on their rear ends that act like snorkels. The snorkels carry air to tinier tubes that run throughout their bodies. (When the bugs are out of the water, they breathe through little holes in their sides.)

The larvae aren't like caterpillars, which change completely when they turn into butterflies or moths. Giant water bugs stay the same shape as they grow up.

As a baby bug grows, it sheds its outside "skin" several times. First, the back of the old, outer skin splits open. Then the larva pulls out. When the larva finally turns into an adult, it has wings. Then it may fly off to another watery home.

BEAKED BUGS

Giant water bugs go for all sorts of prey. Larvae nab tiny water creatures. But older bugs catch bigger prey, such as frogs, fish, and salamanders. Here's how:

When a goodie goes by, the giant water bug snatches the prey with its clawed front feet. Then it stabs its beak right into the creature and squirts in some chemicals. The chemicals turn the animal's insides This young bug is breathing through its rear end! it pokes a tube-like snorkel through the water's surface to take in air. The air then passes through the snorkel and into tiny tubes inside the bug's body. into a goo, which the bug can suck up.

A giant water bug also tries to fight off its enemies. If a duck, heron, or fish tries to eat it, the bug may try to bite back.

Giant water bugs can bite people too. If you want to scoop one up, use a net. But it's more fun to watch one in action in the water. So if you live near a pond, lake, or a quiet stream, go on down - and check out a giant!