Friday, April 16, 2010

Sand Gnats

I have been outside all day. I have been bitten no less than a 100 times.

Sand gnats as we call them, are members of the family Ceratopogonidae or "biting midge" family. The sand gnat that seems to be at its worst when the fishing is at its best! It hatches out in mass numbers when the temperature and season are just right for outdoor activity. Sand gnats are insects and therefore have a typical insect life-cycle that consists of four primary stages: egg, larva, pupa and adult. Eggs are laid in marsh mud, decaying plant material, and even standing water. Female gnats bite humans and other animals to extract a blood meal that is necessary for the successful development of their eggs.

So why does it hurt like mad when a gnat takes a meal from your arm or, even worse, your scalp? The secret is in the mouth parts. Sand gnats don't just puncture your skin like mosquitoes do. Instead they rip it open using sharp cutting teeth located on the mandible. After inserting two sharp, sword-like blades into the skin as anchors, the sand gnat uses the cutting teeth to rip up the skin and get the blood flowing. As if that weren't enough, the gnat then squirts a chemical into the open wound to inhibit blood clotting. The tiny pool of blood that forms is then sucked up through a straw-like structure called the proboscis. Some human victims have allergic reactions to the chemical and must endure itchy red spots or even swollen welts.

1 comment:

angelina said...