Bug on the Water

It is Spring. The rain is a bit warmer. The days are a bit longer. The early flowers are beginning to poke their heads up in the fields and in the yards.

And out in the woods the buds are showing on the trees and bushes.

In my neighborhood the flowers have paused for a moment. The Cherry blossoms were magnificent. Even the fall of the Cherry blossoms was nice; it looked like a late snow fall. Now we are awaiting the Dogwood trees which burst open, all in the same week, throughout the neighborhood.

Back to the woods the buds and nascent leaves are showing red and green throughout the undergrowth. The Persimmon trees still have tight buds. The blackberry vines are showing buds that promise a sweet treat in late summer. The Dogwoods in the deep woods are preparing, just as the ones in our neighborhood, to burst open in all their glory.

But what of the bugs. I have seen one or two of the bright yellow Cloudless Sulphur Butterfly (Phoebis sennae) of Virginia in the fields. And while on the trail I have been passed by several large bumble bees. But its not up, but down that I want to look.

In the stream that the trail crosses and recrosses I can see small bugs, True Bugs as it turns out, darting around as they chase and follow each other. They skate on the waters surface from the edge of the bank into the slight current of the small stream. These are Water Striders, insects of the Order Hemiptera, meaning “half-wing” due to their divided fore wings. But it is their feet that are the most amazing and which give them the ability to glide on the surface of the water.

These insects spend their life first beneath and later on top of the surface of streams and ponds. They are sometimes carnivorous and prey on smaller and less agile bugs that come into their territory. And they delight us with their quick movements as they sprint across the water’s surface. This ability is due to the size of their long feet/fore legs which rest on the water. Their long legs distribute their body weight across the surface of the water and at each foot they are amply supported by the water’s surface tension. They can glide across the water’s surface without breaking through. The Water Strider’s body and legs and feet are covered in tiny hairs which trap air bubbles when in contact with water. These hairs covering the little bug’s entire body are water repellent. These hairs not only help the Water Strider to distribute their weight on the water’s surface but allow them to quickly shed any water that might splash onto their body and weigh them down.

As I stand on the edge of the bank, I watch these Water Striders dart across the surface of the stream. Their quick movements are mesmerizing as the bugs chase each other across the surface.

These are not the only insects in the streams. Right now the nymphs of the Mayfly (Order Ephemeroptera) and the Stonefly (Order Plecoptera) are beneath the water’s surface. They remain there for several years after they hatch. Then as early Summer warms the air and the water, the oldest class of these insects will emerge as adults and fly up from the surface in clouds that can easily be seen. The nymphs of these two insects are especially important indicators of the health of the streams as the insects are very susceptible to pollution. The clouds of these insects above the water are indicators of a healthy stream. And these clouds provide a tasty treat to the fish of the streams.

Below the clouds the Water Strider skates across his territory.