Common Pests

Rats

The Norway rat is common in most parts of United States & Canada. Rats attack the food of man in the farm fields, orchards, and livestock facilities, during its processing, storage and transport, and while it is in our supermarkets, restaurants and homes. What rats do not eat, they spoil by contaminating it with their urine, feces or fur. It is estimated that rats and mice destroy enough food each year to feed 200 million people.

Mice

Mice are common in all parts of North America. The house mice is a dusty grey in color and measure overall from 110 to 150 mm (4 1/2"- 6"), with large ears and long tails. The deer mouse is pale grey to reddish brown in color and has a bi-colored tail, white below and dark above.Mice are nibblers and thus tend to make small holes or other slight damage in many places rather than a lot of damage at one place. The mouse has a keen sense of touch, smell, and hearing. They can run, climb, jump and swim very well.The house mouse is considered one of the major structural pests, causing serious economic loss, health hazards and an unsanitary environment.House mice eat about the same food as humans, including cereals, seeds, fruits and vegetables and are especially fond of sweet liquids. Because they nibble, they may feed as often as 15 to 20 times each day consuming only a small amount of food each time. Deer mice feed on seeds, nuts, and insects.

Carpenter Ants

In their natural surroundings, carpenter ants are beneficial insects. Excavation of galleries in wood has earned them their name. They are beneficial since they feed on many pests. They are the largest of our common ants, the brown or black workers measuring from 6 to 13 mm (1/4'' to 1/2") in length, while the queen may be more than 25 mm (1'') long. In late spring and early summer, mature carpenter ant colonies produce winged adults. These swarm in mating flights, and may be a nuisance around homes at these times. Outdoors, they nest in any wood that is in close contact to a moisture source, for example, stumps, landscape ties and wooden fence posts. In buildings, they often make their nests in hollow doors, in wood cabinets near dishwashers, in damp locations behind baseboards, fireplaces, window frames, and in basements and attics. Carpenter ants will rarely do extensive damage to wood. They usually limit the size of the colony to the area of the damp wood. Several so-called satellite colonies may, however, be constructed in the same structure. Carpenter ants may be seen in infested buildings at any time of the year searching for food at considerable distances from their nest. In some colonies, a dormancy period occurs for several weeks during the winter months. Although they chew their way through wood, leaving frass particles resembling sawdust, they do not eat wood. Instead, they feed on a wide range of insects, plant materials and, occasionally, on household foodstuffs.

Non-Wood Boring Ants

Ants are one of the most successful groups of insects. They are social insects that live in colonies which are usually located outside, but may enter buildings for shelter and/or food. Ants feed on practically every kind of food but those entering homes are often looking for sweets and/or protein-containing substances. Ants of concern in homes include Pavement Ants, Thatching Ants, Little Black ants, Harvester Ants, Moisture Ants and Carpenter Ants.

Worldwide, there are over 2,200 species of termites. In the United States, 500,000 homes are treated for termites each year at a cost of over $1 billion. Subterranean and damp wood termites are responsible for the most of the damage to wooden buildings in the Pacific Northwest. Termites are nature's recyclers, breaking down and returning to the soil the cellulose-containing materials of fallen trees and decaying wood. Termites derive nutrition from wood and other cellulose materials. They cannot digest the cellulose themselves. Instead they are dependent on one-celled protozoa in their stomachs that break down the cellulose into simpler compounds that the termites can use as food. Termites colonies are complex social organizations. A colony typically contains several castes including workers, soldiers and reproductives. Each caste has a precisely defined role within the colony.

Bedbugs are gray to reddish-brown in color, are oval and flat, and are approximately 1/16" to 3/16" (1 to 5 mm) in size. Bedbugs will be closely associated with the bed and surrounding objects such as headboards and end tables. The bat bug is similar in appearance to the bedbug, but has a heavier amount of setae on the pronotum and differs greatly in preferred habitat. The location where the insects are found can help distinguish between them. Bat bugs feed on bats and will originate in attics and wall voids where bats are roosting. Insects found in the middle of the floor, especially during the day, with no specimens found around the bed may indicate a bat bug infestation with entry into the living space via gaps around ceiling lights and other fixtures. Once the type of insect has been determined the appropriate control measures can be implemented.

The carpet beetle is a very common insect in homes and has world-wide distribution. The larvae of carpet beetles may cause serious damage to materials of animal origin such as wool, fur, hair and feathers. Carpet beetles also feed on dead insects and are often found in homes that have had cluster-fly infestations. Carpet beetles will live outside and have been found feeding on plant pollen.

To the untrained eye, all cockroaches may look alike. However, there are actually five species of significance. German, Brown-banded, Oriental, American and Common Wood cockroaches are all unwelcome pests. The main attractions for a cockroach are food, water and shelter. To them, almost anything is food—any foodstuff, paper, cloth, plants and even glue used for binding books. They can be found in every part of the home, but most prefer some kind of damp environment. Since most cockroaches are active at night, many people may be completely unaware of their presence in their home. Cockroaches are a public health concern because they have been known to carry Salmonella bacteria—the organisms responsible for food poisoning. Although some people worry that admitting to an infestation of cockroaches indicates poor housekeeping, at times even the most conscientious housekeeper may find it impossible to avoid an infestation.

The European earwig is one of the common pests in homes and gardens. If present in large numbers, the earwig may damage flowers, fruits, and vegetables. The adult earwig is about 12-19 mm (1/2" - 3/4") long and reddish brown in color. Both males and females have a pair of large, curved forceps at the rear of the body. The adults have a pair of wings but seldom fly. The adults live for usually one year and die during the winter months.In their search for food and shelter, earwigs crawl over the ground, readily entering houses. They forage at night and hide in dark secluded places during the day. They eat both plant and animal food. The European earwig moves from place to place largely through the agency of man. Wandering at night, it crawls into any available hiding space during the day, and thus it may be carried long distances in bundles of papers, flowers, or packages.The European earwig was introduced to this country from Europe and it has no natural enemies except man. Thus, this insect is rapidly growing in numbers.

Fleas are troublesome pests carried on mammals and birds. They infest homes, bird cages and poultry houses. Both males and females bite and suck blood. The bite often leaves an itchy, red spot. Some kinds of fleas transmit diseases such as bubonic plague, endemic typhus and tularemia to humans. Several kinds of fleas attack mammals and birds. The Dog flea and the Cat flea, which look very much alike, are the most widespread and the most troublesome as household pests. Both species attack dogs and cats, and sometimes man; especially if the family pet's are temporarily away. The adults are small, wingless insects with hard, dark-colored bodies. The female usually lays her eggs loosely among the hairs or feathers of the host, where they will stay for a few days and then drop off. In homes, they develop in crevices in flooring, and along baseboards, under edges of rugs, and between cushions in upholstered furniture. The adults can live for several months without food, so infestations may last for weeks or months after pets are removed.

Flies are a common pest in homes and commercial establishments. Flies normally are associated with decayed or spoiled debris. In this kind of habitat of both feeding and breeding, it is a certainty that flies and their maggots will come into contact with a wide variety of bacteria. Because they are associated with disease and because they can readily gain entry to buildings, flies pose significant pest problems.

Silverfish have a torpedo-shaped body that is covered with metallic, silvery scales. They are nocturnal, and prefer out of the way, humid, dark areas. They may be brought into homes in cardboard cartons, books or papers, that have come from infested areas. The adult lays an average of 100 eggs and the best development occurs at a temperature of 22-27°C (72-80 degrees Fahrenheit) and at a relative humidity of 75 - 97 percent. Silverfish can damage books and papers. Signs of their presence can be seen in irregular chewing marks, holes eaten directly through paper, small dark feces and minute yellowish stains associated with feeding.

Spiders are found commonly throughout North America. About twelve different species are commonly found in homes. Spiders have two body regions, connected by a restricted waist. The fused head thorax has two jaws, two palps, eight legs and eight or fewer eyes. The abdomen is unsegmented and hold the spinneret. The harvestman or daddy-long-legs spider differs in that its abdomen is segmented.

Springtails are a group of very small to minute (1-2 mm) wingless insects. They often occur in enormous numbers on the surface of water, on snow, in mushroom houses, in flowerpots and other damp places. They occasionally invade houses and are particularly common in basements, bathrooms and kitchens. Springtails feed on algae, fungi and decaying vegetable matter. These insects are among the most troublesome swimming pool pests. They also occasionally become pests in maple-sap buckets or on seedlings in greenhouses. Damp environmental conditions are preferred since springtails respire through their cuticles. If their habitat becomes too dry, they will actively seek a more favorable environment. They may move indoors through window screens, open doors, through vents or with the soil of ornamental plants brought into the house. After entering a house, they are often trapped in sinks, basins and bathtubs. They may also be found in cracks and crevices, or occur in damp wall voids.

Stored product pests are found living in dried products such as dried fruits, spices, flour, bran, peas, dried vegetables, dried flowers, grain, cereal products, dog food, nuts, candy, macaroni and other similar products. Stored product pests contaminate far more food than they eat and are common in food processing plants as well as domestic settings.

The tent caterpillar is one of the most conspicuous and familiar insect pests in the Northwest. Their silky, white tents can easily be seen covering the tips of tree branches. Tent caterpillars eat the foliage of many deciduous trees and shrubs, especially alder, willow, fruit trees, and roses. During a heavy infestation they will migrate and feed on many other plants. Tent caterpillars damage plants by eating the foliage as it emerges. A healthy plant will usually grow out new leaves by summer, but its growth may be reduced, making it more susceptible to the stresses of drought, cold, disease, and other insects. For this reason, it is a good idea to monitor tent caterpillars closely and control them if necessary. Fortunately, there are effective non-chemical control methods available.

There are several varieties of wasps in North America, including the yellow jacket, hornet and paper wasp. Color ranges from black to combinations of black with yellow, white or brown markings. The slim, winged body measures 10 to 19 mm (l/2" to 3/4"). All wasp species have chewing mouth parts and the females possess a stinger.

The wasp colony consists of queens (fertile females), workers (sterile female), and males. In late summer the queens and males mate; the males and workers die off and the fertilized queen over winters in a protected site. In the spring the queen collects materials from plant fiber and other cellulose material and mixes it with saliva to construct a typical paper type nest. Wasps are very protective of their nest and though they will use the nest for only one season the nest can contain as many as 10,000 to 30,000 individuals. Wasps are considered to be beneficial because they feed on a variety of other insects.