by Bonnie Ross
Among aquatic insects, long-legged water striders are about
the easiest to see. They live on the water surface film and
they tend to congregate in large numbers. One genus, would
you believe, lives on the surface of the ocean, sometimes
many miles from land!
Water striders belong to the family Gerridae within the order
Hemiptera, or "true bugs." Being a "bug" they do not undergo
complete metamorphosis, and don't go through the larval and
pupal life stages many other insects, such as butterflies and
beetles, experience. Instead they hatch from an egg, then
become a nymph and undergo five molting periods called instars,
each causing them to increase in size and look a little more
like a mature adult. Water strider adults overwinter in
protected areas near the water's edge. Eggs are laid in
the spring and summer.
As with all aquatic insects, adaptations allow them to survive
in their unique niche. Water strider legs are adapted to
"skate" on the surface film as they possess fine hairs that
resist water saturation and do not break through the surface
film. They are carnivorous, using their short forelegs for
grasping prey rather than for skating. They capture
terrestrial insects that fall on the surface or aquatic life
forms that come to the surface to breathe.
Being a member of the "true bug" clan they are equipped with
a long proboscis normally used to inject their prey in order
to suck out body juices. The proboscis can also deliver a
wicked sting to human hands. So, when searching for water
striders to observe, it is best to just watch them and
appreciate their unusual place in Nature.
This article originally appeared in our Fall 2006 Newsletter