Spiders
The general appearance of spiders is familiar to most. They are closely related to insects but spiders have eight legs; insects have only six. Spiders belong to a group of animals known as arachnids, which also includes mites, ticks, and harvestmen (daddy longlegs). Few organisms create as much hysteria as spiders; this fear is largely unwarranted. In fact, spiders are beneficial to humans because they help to control a wide variety of indoor and outdoor pests. |
Wolf Spiders hunt day and night and are often
observed running on the ground.
|
Biology
In the U. S., four types of spiders are considered dangerous: the
black widow, brown recluse (or violin) spider, the aggressive house (or
hobo) spider, and the tarantula. Bites from these spiders can be painful,
but they bite only when provoked or under certain circumstances.
Poisonous spiders are rarely, if ever, found in Maine.
Children may be especially sensitive to spider bites, but many bites blamed on spiders are more likely from fleas, bedbugs, mosquitoes,
ticks, or mites. Most spiders are too small to have a dangerous amount of venom or a bite that can penetrate skin, or too weak to harm humans.
Jumping spiders are often found at windows.
Management
Unwanted spiders, and their webs, can usually be
removed simply by sweeping or vacuuming. In most cases this is
sufficient. If more action is necessary, study the situation to locate the
spider’s source of prey. Are spiders thriving on night-flying insects
that are attracted to security lights? Are insects being attracted by poor
sanitation habits? Eliminating the food source for the insects will
reduce the food source for the spiders.
Maintenance to reduce spiders includes:
- Moderate the use of exterior lighting. Use sodium vapor lights
where possible.
- Position lights away from buildings rather than mounting them directly on the exterior.
- Vacuum adult spiders, webs, and egg sacs. Immediately empty bag to prevent their escape.
- Remove litter and clutter from the sides of buildings, keep all areas free of unneeded, unwanted items.
- Seal openings in outdoor structures, playground equipment, bleachers, fencing, outdoor furniture.
- Repair screens and fill cracks and crevices around windows, doors, and foundations.
- Use weather stripping around windows and doors.
- Eliminate moisture from crawl spaces.
- Prune plants 6 feet away from buildings.
Chemical control
Chemical control of spiders is rarely, if ever, needed, is often ineffective, and is not recommended.
Anyone making pesticide applications on school property must be
licensed by the Board of Pesticides Control. See "Standards for
Pesticide Applications and Public Notifications in Schools".
Printable Version [PDF]
Additional Resources:
Photo credits:
Joseph Berger, Bugwood.org
