Click on images to see larger view
Clemson University-USDA Cooperative Extension Slide Series, Bugwood.org
Cockroaches are ancient insects that have changed little over eons of time. To most people these insect pests are the most repulsive. Primarily nocturnal, they emerge from their hiding places to feed. If you turn on the light, they will rapidly scatter. Several species are responsible for our infestations. The four most important species causing our infestations are the German (Blattella germanica), brown-banded (Supella longipalpa), Oriental (Blatta orientalis), and American (Periplaneta americana). A common species, the wood-cockroach, is a native of our woods and frequently attracted to lights in our homes, but is not a major pest. Other exotic species of cockroaches, such as Cuban, Asian, smoky-brown, and Australian, may also be present in the Northeast in certain areas.
Cockroaches are pests throughout the United States. They are annoying and, when abundant, are also destructive. Cockroaches, also known as waterbugs, croton bugs or palmetto bugs, destroy food, and damage fabrics, book bindings and other materials. When cockroaches run over food they carry filth and may spread disease. They secrete an oily liquid that has an offensive and sickening odor that can ruin food. This odor may also be imparted to dishes that are apparently clean. Excrement, in the form of pellets or an ink-like liquid, also contributes to this nauseating odor. Some people are allergic to infestations of cockroaches and can become ill.
Life Cycle of the Cockroach
The cockroach has three life stages: the egg, nymph, and adult. Cockroach eggs are deposited in groups in a leathery case or capsule. This capsule is usually dropped or glued to some surface by the female as soon as it is formed; however, some females such as the German cockroach carry the capsule protruding from her body until the eggs are ready to hatch. There may be 30 to 48 eggs in the capsule of the German cockroach, but capsules of other cockroaches may only have 10 to 28 eggs.
The newly-hatched nymphs have no wings, and they shed their skins (molt) several times before becoming winged adults. German and brown-banded cockroaches may have several generations per year.
Cockroaches prefer dark, protected areas to hide and rest in during the day. These areas 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 windows or door frames, behind loose baseboards or molding strips, on the underside of tables and chairs, in the bathroom, in radio and television cabinets, and in computers. The German cockroach is usually found in the kitchen and bathroom although it may be found all over the house. Cockroaches are active at night, so daytime observation is a good sign of heavy infestation. Although cockroaches prefer starchy foods and meats, they will eat anything of plant or animal origin.
Inspect all baskets, bags or boxes of food, firewood and laundry brought into the house. Inspect food containers, furniture, appliances and clothing. The adults and young will be easy to recognize, but because some cockroaches glue their egg cases to various surfaces, take particular care to look for the eggs. Destroy any cockroaches or egg capsules. Make it difficult for cockroaches to enter by passing through floors or walls by filling all openings around pipes with patching plaster putty or plastic wood, particularly if cockroaches are coming in from adjoining apartments. Keep door and window screens in good repair, and make sure that there are no cracks between them and the frames.
Using weather stripping and caulking where plumbing passes from infested areas, and eliminating hiding places by caulking cracks and crevices in dark, moist areas, will discourage cockroaches from migrating into a building or from another part of a building.
Cockroaches need food, water and shelter. Do not allow food particles to accumulate in areas accessible to cockroaches. Common feeding areas include unwashed dishes, pet feeding dishes, uncovered pet food containers, litter boxes, waste containers, and areas under refrigerators, stoves, sinks and furniture. Repair faulty plumbing and eliminate unnecessary newspapers, boxes, rags, and similar items that provide hiding places.
Cleaning will aid considerably in cockroach control. Take away their food supply. Store food in tight containers and avoid spilling flour, cereals and other dry materials in cupboards or on pantry shelves. Do not leave remnants of food on tables or in kitchen sinks overnight. Sweep up any crumbs or bits of food from the floors of kitchen, pantry and dining area. Put table scraps, vegetable parings and other waste materials in tightly covered garbage cans.
Boric acid is a highly effective chemical for effective German cockroach control. The bait is contained in a childproof bait device. Twelve bait devices should be placed in the kitchen, bathroom and other cockroach-infested areas to obtain satisfactory results. These products have no odor and can be applied without removing food, pots, pans or dishes from cupboards. Testing has shown these products may be effective for three to twelve months depending on the environment of the home or apartment.
The most commonly used dust for cockroach control is boric acid (Zap-A-Roach, Boric Acid Roach Killer), which is usually applied as 99% active ingredient. It is effective if wall voids and most cockroach harborages are thoroughly treated. Boric acid dust is most effective when applied to hard-to-reach places or in dry areas where the dust can be transferred from the treated surfaces to the cockroach. This product is odorless, non-staining and non-flammable.
Cockroach Traps- Used for Monitoring
Cockroach traps - small, open-ended boxes - contain an attractant and a sticky substance that retains the insects once they enter. Traps can be effective in catching the occasional invader, but will not eliminate established colonies. Use them to locate infestations and to determine when populations require additional treatment. Traps are most effective when placed against walls under sinks, in cabinets and in basement corners. If two nights pass without a capture, move the traps to another likely area.
Despite good cultural practices, pests and diseases at times may appear. Chemical control should be used only after all other methods have failed.
For pesticide information or other questions please call toll free: 877-486-6271.
Revised by UConn Home and Garden Education Center 2016.