Venomous Insects: Our aversion to ‘creepy crawlies’

If you have ever been stung by a bee, wasp, or bitten by a fire ant or spider, you will try to avoid these pests at all cost. The inborn hatred of “crawling things” possessed by some people is unfortunate but can be real.

An extreme fear of bugs, caterpillars, spiders, ants and bees is really not warranted, because there are very few insects that can harm the body seriously. Nevertheless, there are a number of insects that can bite and sting painfully. It is often true that the worst looking insects are generally harmless; while some of the most painful experiences result from contact with very innocent looking specimens.

Bodily pain and illness may be caused by the venomous of insects applied to the body by stinging, biting, nettling with hollow poison hairs, applying caustic and corrosive fluids in the skin and by poisoning.

Chewing insects are rarely able to cause much pain. The “pinching bugs,” probably the most furious looking insects can scarcely break the skin. The really painful bites are made by insects with piercing mouthparts, accompanied by the introduction of venom.

Besides the spiders, ticks, and centipedes, the two-winged fly family (mosquitoes, buffalo gnat, horse fly, stable fly, etc.), true bug family (bed bug, assassin bug, water scorpion, etc.), bloodsucking lice and fleas are notorious for the injury inflicted by their bite.

Many insects regularly feed on animals’ blood, including man’s, as their only food. Anyone who has pets or has ventured out into the woods or lakes has experienced the bites of ticks, mosquitoes, and buffalo gnats. The stable fly is a constant companion of horses; cattle and sheep, all summer long, inflicting painful bites.

The other methods of applying venom are less serious than that of biting. The stinging insects are largely a peaceful and defensive lot inflicting their punishment almost exclusively on creatures that has injured them or disturb their nests. Fire ants sting viciously, when disturbed, attacking anything that is in their vicinity.

Only two spiders — the black widow spider and the brown recluse spider — feeds on insects and other tiny animals. When they come in contact with humans, their bite is a very unpleasant experience. Even one of these spiders in a building is too many.

Some of the ants and certain beetles possess venom, but have lost the stinger with which to inject it. They spray the poison from the tip of the abdomen into a wound made by the mouthparts. The bombardier beetle ejects a bitter fluid, which is discharged with a distinct popping sound and a small cloud of vapor that looks like the smoke from a miniature cannon.

There are certain insects that carry a venomous substance throughout their body, especially in the blood rather than confined in a gland. In some cases, such as the blister beetle, the poison possesses caustic or blistering properties when the insect is accidentally crushed on the body.

Among the most interesting protective structure that an insect possess are the nettling hairs of many caterpillars. These structures are similar to the poison hairs of the stinging nettle plant. Not all hairs of the body on caterpillars are this type. Certain ones are hollow and connect at their bases beneath the skin with poison glands. When the hair penetrates the skin, the poison is released at the broken point creating a serious skin itching.

The best known of the nettling caterpillar is the IO moth, saddled-back caterpillar and the puss caterpillar. Unfortunately, there is nothing distinctive about the appearance of this group of caterpillars. The gardener just has to learn to recognize them and avoid their presence.

As was pointed out earlier, there are many more dreadful-looking caterpillars that are totally harmless. For example, an entirely harmless, though evil-looking caterpillar is the tomato hornworm with its red horn near the end of the abdomen.