NPIPM:Blatella germanica
Authors: Ashley Mueller, Buyung Hadi
Cockroaches are a very common insect, and they can be an invader of homes and buildings. They are medically important pests, and their presence indoors is a concern because they can cause health problems. They are able to transmit various diseases that affect the human digestive system. Cockroach legs and bodies easily spread disease-causing organisms to food, utensils, and surfaces.
Cockroaches undergo three developmental stages: egg, nymph, and adult. The nymphs often resemble the adults, but they are smaller in size. Cockroaches are highly adaptable to their surroundings. They are able to survive for a period of time without food and water. Active during the night, their flat bodies allow them to easily hide in cracks and crevices during the day. Determining the extent of cockroach presence is an important step in managing an infestation.
Identification
The adult German cockroach (Blatella germanica) is about 1/2 to 5/8 inch long, and it is tan to light brown with two characteristic dark bands on the upper side of the thorax running from the back of the head to the wings. Although these cockroaches have wings, they are unable to sustain flight.
Habitat
The German cockroach is one of the most successful human-dwelling invaders in the U.S., and it is often found in homes, hotels, and restaurants. They are mainly an indoor species, although they will go outdoors to migrate to another structure. German cockroaches are active at night, and during the day they hide in cracks and crevices.
Life Cycle and Seasonal History
German cockroaches have a very high reproductive rate, and they often have many generations overlapping at one time. Adult female German cockroaches can live approximately four to seven months. The late summer months are usually when German cockroach infestations are at their highest.
Human Interaction and Urban Impact
German cockroaches are commonly found in warm, damp places like bathrooms and kitchens. Their flattened bodies allow them to pass through cracks around windows and doors and along a building’s foundation. German cockroaches eat a variety of foods, including sweets, starches, meats, and grease.
Prevention and Management Approaches
It is very important to use good sanitation practices in the kitchen and other areas of the home where food is prepared and served to prevent cockroach infestation. Clean spilled foods from surfaces; do not leave dirty dishes overnight; and store food in well-lidded containers. Food should be stored in containers with tight-fitting lids.
Prevent cockroaches from entering the home or building by sealing around windows and doors and by caulking cracks around pipes and other cracks on ground-level walls.
Cockroach management starts with surveying and monitoring. Sticky traps placed in strategic locations should provide some information on the extent of the infestation. Place traps against a wall, in corners and drawers, and along shelves and counters. Many commercially available traps contain baits to attract cockroaches. If monitoring reveals heavy harborage areas, baiting is an effective control method against cockroaches. Check the traps frequently and replace as necessary.
Vacuuming cockroaches using a crevice attachment may be a good option. Discard the vacuum contents after use, and it’s recommended to seal the contents in plastic bag to prevent escapes by those cockroaches that survived the vacuuming process.
The use of aerosol foggers to control cockroaches within a building is not effective. The application of aerosol foggers may disperse the cockroaches further into the structure, resulting in more difficult control. If an insecticide is used to control cockroaches, always use precaution and follow the label carefully before using. Insecticides have a certain amount of toxicity to mammals; children and pets are especially at risk.
Other Online Resources
University of Nebraska-Lincoln
For information regarding labels of chemical control options, please visit NPIC MAPL
