German Cockroaches

How To Kill Them and Control Infestation

German Cockroaches

Picture of German Cockroach

The German Cockroach is the most common of all roaches found in America. The German roach is most likely to infest your home. Unlike the American Roach, the German variety prefers to nest indoors. They cannot survive outside for prolonged periods. They are hitchhikers and are often introduced into homes in luggage, used clothing and second-hand furniture.

When neighbor homes are exterminated, they frequently will escape and move in with other neighbors. That's providing those neighbors give them easy access. German Cockroaches are hard to control because they breed at an amazingly rapid pace. The numbers produced over a short period can be mind-boggling.

A female German Cockroach will produce 5-6 egg capsules over her adult lifespan of 100 to 200 days. Each capsule contains 30 to 40 eggs. From egg to adulthood takes only 100 days. New females in the batch are then quite ready to reproduce. Four to five generations can be created in about a year. Go ahead. Hit your calculator. The result is an incredible number roaches spawned by just one female.

Identifying Characteristics

German Roaches are about half the size of the American Cockroach with an adult length of about 1/2 to 5/8 inches long. Primary color is light brown with touches of tan and pale yellow. They have darker brown bands running length-wise from the back of its head. Adults have wings but can't really fly, but can glide from short elevations.

Habitats and Behavior

German cockroaches rarely nest outdoors. Infestation and nests are mainly indoors. They nest in areas near food, water and humidity. They forage on food scraps, garbage and even things like toothpaste and wallpaper glue. They prefer dark, secluded areas near kitchens and bathrooms. Particularly in cabinets under sinks, beneath stoves and refrigerators and behind toilets.

Like all roaches, the German variety is active at night preferring to hide during the day in cracks, crevices and narrow openings where they find security and quick retreat. If you see them during daylight hours, that could be an indication of very high infestation. Roaches will be expelled from colonies that are way over populated or when food sources become diminished either because you've practiced good sanitation and/or there are too many roaches for the food supply.

Heavy infestation can occur rapidly because of their reproduction rate. Unless an infestation is discovered early, they will be very hard to control without use of insecticides and a lot of patience. Direct spraying of those you see will not diminish an infestation. They have to be destroyed at the nest sites to have meaningful effect.

Best Way To Prevent Infestation

You must keep them out. If you bring boxes, grocery bags, old clothes or second-hand furniture home, check them carefully. Sometimes the roaches will migrate from other homes and adjoining multiple housing units. You must seal cracks and crevices where they are likely to gain entry.

Pay special attention to where plumbing, conduit and cable enters the home. Caulk around windows and screens. Check molding around doorways. Keep in mind there are other types of roaches, so preventive measures will help ensure against all types of roaches as well as other insects.


Practicing good sanitation and cleanliness is a priority. After all, they thrive in moisture and where food sources can easily be found. Exposed food items cannot be left out. Do the dishes, empty sinks and empty trash before going to bed. Thoroughly wipe-down down counters. Keep dry foods tightly sealed in containers. Limit eating to dining areas only. Check for dripping faucets and plumbing and repair them quickly.

Sanitation and cleanliness are equally important outside. Although German Roaches are more likely to nest inside than outside, they will also go through cracks to get to outside food and water sources. It is crucial to bag all trash tightly before placing it in garbage cans. Garbage containers should be thoroughly washed and cleaned regularly and placed away from exterior walls and doors.

Use of Safe, Yet Effective Insecticides

If preventive measures do not work and you see roaches, insecticides must be used. Always use the safest insecticides that will accomplish the objective. Always read the label and apply as directed. There are several approaches to controlling and eliminating German roaches with insecticides. It takes patience and commitment with repeated applications according to product instructions.

Roach Baits. Like all roaches, German Roaches colonize in nests and come out mostly at night. Using roach baits are very effective and the best way to kill large numbers. Roach baits come in different forms. Roach bait stations and Roach Gel Bait. They are what's known as a "secondary kill" insecticide.

A low volume of active insecticide is mixed with an attractant. The active ingredient is a "slow kill" which permits the roach to return to its nest to infect other roaches through sputum, feces and even the corpses of dead roaches. The strategy is targeted at the entire colony versus just one cockroach. In a sense, the infected roach becomes the killing agent.

Insect Growth Regulators (IGRs). Growth regulators controls roach populations by inhibiting young roaches from maturing. If females do not mature, they are incapable of reproducing. IGRs are essential in controlling German Cockroaches long term. Brands include Gentrol, Nyguard, Nylar, Starycide, Precor, and Sumilary. Most hardware stores and do-it-yourself pest control outlets sell IGRs.

Read more about Insect Growth Regulators

Liquid Insecticide. A safe liquid insecticide like "CY-Kick CS" will kill roaches soon after they make contact. Its active ingredient is an extract from specific varieties of the Chrysanthemum flower, yet is highly effective. A great number of roaches can be killed initially by applying the spray on likely travel areas, around plumbing, and in cracks and crevices.

Cy-Kick CS is an odorless, non-staining liquid and is categorized as a low-toxic insecticide. All insecticides have some degree of toxicity, but this is one is safe when used as directed. It is mixed with water to significantly reduce the volume of the active ingredient.

Always let it dry before permitting pets and people near the sprayed area. It can be applied both inside and outside. When using roach baits, do not spray near the baits because a liquid insecticide will repel roaches away from bait stations.


Related Information

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This page was last modified on 5 September 2012 at 10:03