Spiders

Many species of spiders are common household and commercial building inhabitants in the southern United States.  Certain common spiders spin webs over outside lights, in corners, crawlspaces, attics, garages and in basements.  Under most conditions outdoors, spiders are considered beneficial because they feed on insects.  However, they are undesirable to most homeowners when indoors, and the unsightly webbing spiders use to catch insect prey usually outweighs this beneficial behavior.

Spiders have eight legs as opposed to insects which have six.

Most spiders hide in darkened areas, cracks or other retreats that they construct out of silk.

Black widow spiders are found in North and South Carolina and contain venom that is toxic to a person’s nervous system.

Brown recluse spiders are not as common as the black widows and are usually found in the western part of the state but have been reported throughout North and South Carolina.

Both black widow and brown recluse spiders can inflict a painful bite and the severity of the symptons depend on many factors including the area of the bite, the person’s size and general sensitivity, the amount of venom injected, the temperature, a person’s immune system, etc.

If you or someone you know is ever bit by a spider and requires medical attention, it is best if you can bring the spider with you for identification.

Spiders do not have wings or antennae and their bodies have only two regions as opposed to insects which have three body regions.

All spiders have a pair of jaw like structures, called chelicerae.  At the end of each chelicera is a hollow, claw-like fang.  Each fang has a small opening in the end through which venom is injected into the prey.

Spiders have spinnerets, located at the tip end of the abdomen which are linked to glands from which silk is spun for web making.

All spiders are carnivorous. Most spiders eat insects but a few of the larger species are big enough to prey on small animals like birds or mice.  A spiders jaw has toothed edges used in breaking up the prey during feeding.  Digestion starts before any of the prey is swallowed.  Some spiders inject digestive enzymes into the prey before they start breaking it up, other secrete digestive fluids as they are breaking the food up with their jaws.  The partially digested food is sucked into the spiders gut.

Management

• Indoor management consist of removing webs and egg sacs and the actual spiders by vacuuming.  Residual dusts and microencapsulation insecticides can be applied to cracks and crevices and spider harborages.
• Outdoor management consists of locating nesting and potential nesting areas and removing them.  Insecticides applied around the foundation should help to reduce insect populations which in turn should help reduce the number of spiders.
• Thorough interior and exterior inspections are always vital to good spider management.