Infestations of Cockroaches ...

German Cockroaches, Blattella germanica, are one of the most common urban insect pests throughout the world. This species of cockroach prefers to live in a humid atmosphere with an average temperature of 70º F (21ºC). Since these are the same conditions preferred by man, it is no wonder that German cockroaches have adapted to living in man’s home, office, ship, restaurant and school. Having had a longer track record of survival on the planet earth (300 million years versus 1 million years for man), it is thought by many that cockroaches are likely to out survive man in the long run. 

Cockroaches are known mechanical vectors of bacteria and other diseases; their fecal material, hairs and cuticle are the source of allergies and asthma for many, and their odor is described as unpleasant, but their most objectionable characteristic is their tendency to appear uninvited at the table. Long considered a sign of poor sanitation, cockroaches are now identified as a public health issue. 

Identification: There are several pest species of cockroaches found indoors and many more non-pest species found in nature.  It is important to identify your cockroach.  German cockroaches are about ½ inch in length, brown in color and have two dark parallel streaks running longitudinally down the thorax.  These dark streaks are present on nymphs (the earlier stages without wings) and on males and females.  The female carries her eggs (20 to 50) in an external capsule which in time becomes as large as her abdomen.   The nymphs go through seven molts in a two month period before reaching sexual maturity and bearing wings.  These cockroaches are found in kitchens, bathrooms, and in other locations with moisture and food.

Biology: Although German cockroaches are attracted as nymphs to the odor of fecal material and as adults to each other, in all life stages the main attraction is food. Even a clean, sanitary area will have sufficient food to sustain a few cockroaches so that it is most difficult to eliminate an infestation through restriction to food alone.

Cockroach Removal: An important task is to identify where cockroaches are hiding during the day since they are primarily active at night. It has been found that the average cockroach prefers to wedge itself into a crack about ¼ inches wide. Since there are numerous cracks of this dimension in any normal setting and since food is also generally plentiful, cockroaches can hide in some very interesting places. Examples include behind electrical plates, inside water coolers, under wall moldings, behind walls, and in plumbing and pipe chases. Of course when cockroaches are more abundant, they will also hide in folded paper bags stuffed next to refrigerators, inside radios on kitchen counters, inside wooden knife holders, under the rim of sink fixtures, and even in recipe boxes. 

Moisture is critical to cockroach survival so breeding usually takes place in kitchens and bathrooms although adults may be found in any room. When a single adult is found climbing up a wall in an office during the day and the office does not have a sink or other water source, than it is a good bet that the cockroach was recently introduced into the office from another infested site. This cockroach could have come out from under the wheel casters of a cleaning cart, crawled through plumbing lines from a neighbor or was flushed into the area because of the use of insecticide sprays at another location.