Occasional Invaders

General Description
Occasional invaders are insects and other arthropods that sporadically enter structures, sometimes in large numbers. By far the most common problem with occasional invaders is that they become an annoying nuisance. Some can bite, pinch, secrete foul odors, damage plants, stain indoor furnishings, and damage fabrics. Even after they are dead, the problem may continue. The bodies of dead insects can attract other pests that feed on them and their bodies; and shed skins, secretions and feces of pests can cause allergic responses and trigger asthma.

Whether they’re insects, mites or arthropods, occasional invaders typically live and reproduce outdoors. They invade structures when conditions indoors are better for them than outdoor conditions. It is important to know the conditions that prompt invasions of unwanted pests. By altering environmental conditions we can make structures inhospitable to pests - an important component of integrated pest management.

General Control
Exclusion is the first step to prevent occasional invaders. Exclude them by using caulk, concrete, screen or hardware cloth (less than one-eighth of an inch mesh) to seal cracks and gaps in a structure’s exterior. Entry points are often present in foundation walls, under siding, around windows and doors, vents, soffits, and where utility lines enter. A plant-free band of rock, gravel or other inorganic material extending 2 feet to 4 feet out from the foundation essentially puts a barrier between occasional invaders and the structure.

Leaky pipes, faucets, misdirected downspouts and faulty grades also can provide moisture that attracts not just occasional invaders but also other pests including termites. The environment around a structure also can be manipulated by reducing outdoor lighting. Mercury vapor lights and white lights can be replaced with sodium vapor lights or low-wattage yellow “bug light” bulbs less attractive to insects.

Various mechanical controls also can be employed. When pests enter in significant numbers, it is best to remove them with a vacuum cleaner. After vacuuming, seal them in bags and dispose of them promptly. Traps are another useful mechanical control. Insect monitors, or sticky traps, can be purchased at local hardware stores, home and garden centers, from some pest control suppliers, or through the Internet. Sticky traps are simply cardboard with an adhesive that pests stick to when walking across them. When positioned indoors at likely entry points, on either side of doors, for instance, they can help monitor for pest intrusions. When numerous pests are caught on sticky traps in the garage, for example, it may be time to apply additional methods before things get worse.

Chemical control with pesticides also can be integrated into pest management plans, but consider using pesticides only after other methods have failed, and with a preference for products that are the least harmful to human health and the environment.