Cockroach Species

The cockroaches most commonly found in and around homes are American, German and Asian. The smallest cockroaches—the German, Asian and brown banded - are close to the same size, and the adults are seldom more than 5/8 inch long (16mm). The larger cockroaches—American, brown, and the smoky brown—are 1–1/4 to 2 inches (31–51 mm) long and are often called palmetto bugs. Though they are generally found outdoors, they can become indoor problems when they migrate or are carried indoors. The largest cockroach will also enter dwellings from outside. Outdoor cockroaches do not survive well indoors, and many times people overreact to the presence of these cockroaches. Often, removal of these outdoor cockroaches from the house

Where to Look for Cockroaches

Cockroaches hide in dark, sheltered places during the day and come out to feed at night. Inside, they may be found around the kitchen sink or drain board, in cracks around or underneath cupboards and cabinets or inside them (especially in the upper corners), behind drawers, around pipes or conduits (where they pass along the wall or go through it), behind window or door frames, behind loose baseboards or molding strips, on the underside of tables and chairs, in the bathroom, and in radio and TV cabinets.
The German cockroach is usually found in the kitchen and bathroom, although it may be found all over the house. The other cockroaches prefer damp, warm places and usually develop in garages, sewers, attics, storerooms and similar locations, and then enter the home from outside breeding sites.
Outside, cockroaches can be found in leaf litter, mulch, under vegetation, in tree holes, and in palm trees.

Prevention and Sanitation

Successful cockroach control requires prevention and sanitation. Vacuuming will eliminate cockroach skins and feces that cause cockroach allergies. Cockroach feces also contain a chemical (aggregation pheromone) that attracts cockroaches to an area. Eliminating the cockroach feces by scrubbing with hot, soapy water will decrease the amount of aggregation pheromone available to attract cockroaches to the area.
Prevention and sanitation can be divided into four categories: exclusion; and elimination of water, food and harborage. Following the recommendations in the four categories will likely eliminate the most important factors that affect cockroach establishment.

Exclusion

• German cockroaches can initially infest a structure when infested grocery bags are brought inside. Inspect groceries for cockroaches before storing. Keep grocery bags in outside storage areas.
• Cockroaches breed prolifically in corrugated cardboard boxes. Discard unnecessary boxes immediately.
• Keep doors and windows shut.
• Keep window and soffit screens in good repair to prevent cockroaches from entering your home.
• Check attic vents and make sure that large openings around outside drainage lines and sewer vents are screened or sealed. Use tightly packed steel wool as a temporary filler until openings can be sealed properly.
• Caulk or otherwise seal cracks and gaps around frames of doors and windows and around plumbing and electrical to help prevent cockroaches from entering your home.
• Seal gaps between door frames and doors with weather stripping.
• Children can transport cockroaches from school to home in book bags and lunch containers. Inspect these items regularly.
• Dwellings such as apartments that are separated by a common wall are particularly difficult situations. An infestation can migrate between apartments via the plumbing within a common wall. Therefore, cockroaches from one apartment can easily migrate to another apartment, infesting a “clean” dwelling. To help prevent this, caulk holes in common walls and around plumbing.
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Elimination of Water Sources
Water is the most important factor in cockroach survival. German cockroaches can survive only 12 days with food but no water. However, if only water is present with no food, cockroaches can survive for about 42 days. Cockroaches often come indoors during periods of drought because they are looking for moisture. Eliminate water sources by doing the following:

• Repair plumbing leaks by tightening connections or patching leaky pipes, especially in kitchen and bathroom areas.
• Do not let water stand in sinks for long periods of time.
• Do not overwater indoor plants because accumulated water will be available to cockroaches.
• Empty pans under refrigerators used to catch water from condensation.
• Be aware that pet drinking dishes, aquaria and pipe condensation (under sinks, in wall voids) can also be sources of moisture.
• Eliminate places outside where water can collect, such as cans, tires and tree holes.

Elimination of Food Sources
Cockroaches do not need large amounts of food to survive, especially in the presence of water, but availability of food can cause populations to increase rapidly. Furthermore, food sources compete with cockroach baits, decreasing their effectiveness. Elimination of food sources includes:

• Store and dispose of garbage properly. The highest concentration of cockroaches in a home is usually around the garbage can and around the refrigerator.
• Seal garbage can lids to prevent cockroaches from accessing food sources. Also, keep garbage areas clean by wiping frequently.
• Dump sink strainers frequently to prevent food buildup.
• Wipe off counters tops often.
• Wash dishes immediately after use. Dishes left unwashed are a major source of food for a kitchen infestation.
• Keep kitchen appliances such as toasters, toaster ovens, microwaves, stoves, ovens, and refrigerators free of crumbs and other food debris. In addition, clean the areas around these appliances.
• Reseal all food after opening, place in a tightly sealed container or store in the refrigerator.
• Seal pet food tightly. Do not leave food and water out all the time.
• Regularly vacuum or sweep under and around furniture where people eat, such as the dining room table. Vacuuming can also remove cockroach egg cases that will not be killed by insecticides. Remember to promptly dispose of the vacuum cleaner bag in an outdoor container.

Elimination of Harborages
In addition to food and moisture, cockroaches require a place to live. The cockroach harborage is critical to its survival. Cockroaches prefer dark places that are warm and moist. Places that provide tight spaces such as stacks of newspaper or cardboard, piles of clothing, or cracks and crevices in structures are ideal harborages for cockroaches.
Harborages not only provide a place for cockroaches to live, but they also can create “pesticide free” zones where cockroaches can hide if insecticides are selected as one tactic in the IPM program. Eliminate harborages by doing the following:

• Seal cracks and crevices. Adult cockroaches can fit into cracks only about 1/16 inch and prefer spaces of about 3/8 inch.
• Pull mulch away from the house. The large, outdoor cockroaches breed prolifically in pine straw mulch and poorly in gravel or on bare soil.
• Stack firewood off the ground and well away from the house.
• Fill tree holes with cement to remove this prime harborage area.
• Keep shrubbery and ornamentals well trimmed and away from the house. Ivy is a favorite breeding place for outdoor cockroaches.
• Keep clutter such as newspapers, bags, and clothing from accumulating.

IPM Approach for Indoor Cockroaches

• Thoroughly vacuum and wipe the premises with hot soapy water.
• Place baits (gel and station type) according to label directions.
• Check baits monthly until populations decrease, then quarterly.
• Replace empty bait stations because they provide additional harborage for cockroaches when empty.
• If populations are very high, a “clean-out” may be needed to knock down the initial population. Use a liquid insecticide mixed with an insect growth regulator, such as hydroprene or pyriproxyfen, in cracks and crevices.
• Place baits in areas not treated with liquid insecticide or place baits four to six weeks after spraying.