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Pest Management
Office 491 College Avenue Orono, ME 04473-1295 |
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Spiders Bulletin #5046 |
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House Spider |
Wolf Spider |
Jumping Spider |
| Spiders have been the subject of years of negative publicity. Their secretive nature, way of moving and predatory nature make them common subjects as villains in folklore and popular media. Fear of a few highly poisonous spiders such as black widow and brown recluse spiders has expanded to include all spiders by many people. Fortunately, black widows and brown recluse spiders are not native to Maine. Spiders can be considered to be beneficial when they feed on household and garden insect pests. It is unfortunate that many incidents of unknown skin irritation are attributed to spider bites. Description & Biology Spiders have two body regions (a fused head and thorax [the cephalothorax] and an abdomen) as well as 8 legs. They are relatives of insects which have 3 body regions (head, thorax and abdomen) and 6 legs. Spiders are silk spinners which can be used to make webs for holding eggs, securing prey, or transportation. Some spiders wait for prey to get caught in their webs while others actually hunt for prey. Chance encounters with spiders or their webbing in unlikely places can render them a nuisance. Some spiders may bite in self-defense when carelessly handled or accidentally trapped. Types of spiders occasionally encountered in the home include wolf, fisher, jumping and house spiders. Wolf and fisher spiders tend to be large, hairy and fast. These tend to wander into houses from the outdoors. Fisher spiders are common along lakes, rivers and marshes and can actually feed on small fish and tadpoles. Jumping spiders, which are also hairy, are smaller and more compact, often move in short quick starts. House spiders tend not to be hairy and are usually stationary, associated with their webbing. Prevention Spider problems can be avoided or lessened by sanitation and exclusion. Clearing out basement clutter (including wood piles) eliminates harborage. Moving outdoor wood piles away from the house also helps. Window and door screens should be intact and tight fitting. Cracks and crevices in the foundation and siding should be sealed or caulked to prevent entrance of spiders. Humidity should be lowered, if possible, in basements and crawl spaces. Using dimmer or yellow porch lights will cut down on the number of flying insects accumulating around the lights thus reducing the numbers of spiders feeding on them. Control Spiders and webs can be removed by frequent dusting, sweeping, or vacuuming in corners, under furniture, behind pictures and other hiding places. Any undisturbed area may harbor spiders. Since spiders eat insects, eliminating household insects will help cut down spider numbers. As a last resort, household formulations of materials such as resmethrin, permethrin, propoxur (Baygon), or pyrethrins sprayed in cracks and crevices and in corners (floor & ceiling) of rooms may be used to control both spiders and the insects they eat. |
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When Using
Pesticides James F. Dill, Pest Management Specialist Clay A. Kirby, Insect Diagnostician 2004 Where trade names are used, no discrimination
is intended and no endorsement by Cooperative |
PEST MANAGEMENT OFFICE | UMCE HOMEPAGE | UMAINE
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