Tuesday, April 26, 2011


NYC has been battling cockroaches for many years. Although the media has been highly concentrated on bed bugs in NYC as of late, (guilty!), let's not ignore the fact that cockroach infestations continue to plague New York City and its surrounding area.

Did you know that cockroaches have been around for 400 million years? If you recall back to your school days when you learned about Darwin's Theory of Evolution, the fact that cockroaches have changed so little over the past 400 million years tells us that they were created almost perfectly for survival since the beginning.  That's great news for the cockroaches, but not so great news for New York City residents and others who are battling these mighty creatures inside their New York apartments and buildings.  New York Exterminators have a lifelong battle to endure, residents to reassure, and a little biology to understand to be victorious in the combat against cockroaches.

There are different species of cockroaches and each has its own preferences of nutrition and habitation.  Some types of cockroaches include:

  • American Cockroach (Periplaneta Americana (Linnaeus))
  • Australian Cockroach (Periplaneta Australasiae (Fabricius))
  • Brown Cockroach (Periplaneta Brunnea Burmeister)
  • Brownbanded Cockroach (Supella Longipalpa (Fabricius))
  • German Cockroach (Blattella Germanica (Linnaeus))
  • Oriental Cockroach (Blatta Orientalis Linnaeus)
  • Pennsylvania Wood Cockroach (Parcoblatta Pensylvanica (DeGeer))
  • Smokybrown Cockroach (Periplaneta Fuliginosa (Serville))
Today we will concentrate on the most prevalent and common cockroach, the "German cockroach".  This specific cockroach is a concern due to its attribution to illnesses, its contribution to the transmission of several pathogenic organisms, and its ability to create allergic reactions in individuals.  The German cockroach may be found worldwide, including New York City.

What does a German Cockroach look like?

With coloring light brown / tan in most cases, the adult spans about 1/2" to 5/8" long with a flattened body, six legs covered in spines, and long antennae.  German cockroaches do not fly.  The adult German cockroach wings cover approximately 1/2 of its abdomen (although non-adults may not have wings, yet), and there are 2 dark longitudinal stripes on its pronotal shield.  (see illustration)

The German cockroach is often mistaken with the Asian Cockroach due to the similar coloring, and the Pennsylvania wood cockroach however note that the Pensylvania wood cockroach lacks the 2 dark stripes on its pronotal shield.  Confirmation of the specific cockroach species is instrumental in any exterminator's success, so whenever there is doubt it is highly recommended to confirm the type of cockroach present with an expert.

Biology of a German Cockroach
Eggs are carried by the female German cockroach until only 1 to 2 days prior to hatching time.  She then deposits her eggs in a safe place.  Female German cockroaches create a robust population through their egg-laying tendencies:  Typically she will produce around 5 oothecae (i.e. "egg casings") which contain anywhere from 30 to 40 eggs each, giving us an approximate total anywhere from 120 to 500 eggs each.  One cockroach can literally multiply into hundreds overnight.  From egg to adulthood, the development time of a German cockroach can vary anywhere from 54 to 215 days with the average right around 103 days.  What this tells us is when German cockroaches are present, there are likely more nymphs present within the population then the actual cockroach population in most cases.  Reports show up to 75% of cockroach infestations are comprised of nymphs.

Where do you find German Cockroaches?
German cockroaches prefer warm and relatively humid environments.  As many have unfortunately experienced, German cockroaches love the kitchen, followed by bathrooms.  Generally they will harbor wherever there is nutrition, so in essence wherever you eat.  Dining rooms, dens, living rooms, and even bedrooms provide prime real-estate for a cockroach, when there is nutrition present.  The German cockroach spends much of its time in cracks and crevices in New York City buildings close to their nutritional needs.  These nutritional needs are not only the foods us humans enjoy, but also other elements such as glue, for example the glue used to hold together paper bags and cardboard boxes.  German cockroaches also find their nutritional needs in toothpaste and even soap.  

The German cockroach's activity will vary upon its life stage with reproducing females being the most active of the bunch.  While the reproducing females are busy bustling about, the males are hanging out resting within their harborage including nighttime, too.  This always makes most of my female clients chuckle ;)  Meanwhile, the nymphs that are on the verge of molting will spend their final 3 days in harborage, too.  This is why many nymphs are missed during a visual inspection and will be a crucial point to remember when discussing the pest control treatment of German cockroaches.

Where do German cockroaches come from?
In many cases, the German cockroach, as well as its other relatives in the cockroach family are introduced into their new environment through the transportation of paper products and packaging for example, cardboard boxes, paper grocery bags, and paper cups.  They can also be introduced into your environment through secondhand appliances so I always advise that you thoroughly inspect any estate sale or garage sale bargain before bringing it into your home or building.  I give the same exact advice on my bed bug blog as this is a common way to unwittingly disperse bug infestations from one home to another.

How do you get rid of German cockroaches?
Understanding the reproduction and harborage habits of the German cockroach, it becomes clear that to completely eradicate the infestation it will require more frequent service.  The clean out service is paramount and must successfully exterminate 95% of the current cockroach infestation in order for the follow-up maintenance visits to be completely effective.  To be cockroach free, the following protocol is the most effective:
  • Prevention
    • Like many other situations, prevention is the best way to keep an environment infestation-free from cockroaches.  It is also the most cost-effective as preventative measures do not require an exterminator.  Always inspect items that are brought into your residential or commercial space to be sure there are no cockroaches harboring inside.  Be aware of everything that is brought into your environment.  Also, proper maintenance of the building itself is a highly effective way to prevent cockroach infestations, as well as many other types of insect infestations.  By reducing entry points you dramatically reduce the risk of a cockroach infestation.  Seal cracks and small holes, especially surrounding electrical wiring and plumbing fittings, and fix leaks immediately.  If condensation or humidity is high, increase ventilation appropriately.
  • Sanitation
    • Sanitation along with Prevention is in many cases the most effective way to prevent a cockroach infestation from having the chance to develop in the first place.  Proper sanitation removes the nutritional source, harborage, and water that cockroaches seek for their survival.  A space that has piles of paper and boxes, opened food containers, and standing water in bowls inside the sink for example provides the optimal environment for cockroaches to live.  Reduce clutter, store food in tightly sealed containers, wipe off countertops, empty garbage properly, and eliminate any standing water to help ward off cockroach infestations.  Regular housekeeping through wiping down surfaces, vacuuming (using a HEPA filter if cockroaches may be present will help prevent airborne debris), and washing down floors will remove any food particles that will feed a cockroach infestation.  Don't forget to pick up Fido's food dish, as pet kibbles sitting in a bowl on the floor are an open invitation for a cockroach party.  If you must keep recyclables inside, rinse them out thoroughly before placing them into your indoor recycle container.
  • Inspection
    • Regular pest inspections by an exterminator with a trained eye as well as the correct tools will help keep your home or building from becoming infested with cockroaches.  Sometimes, even when a home or building owner is religious about sanitation and prevention, a cockroach can still find harborage within the indoor environment.  Through regular pest inspections, any potential infestation can be treated before the situation gets out of hand.
  • Initial application
    • Should your exterminator find the presence of cockroaches in your home, apartment, or building, he or she will recommend an initial application, often referred to as the "clean out service."  As mentioned above, the purpose of the clean out service is to remove 95% of the cockroach infestation in a single treatment through the use of residual baits, liquid pesticides, aerosol applications, microencapsulated products, and/or dusting within voids.  Each situation is unique so each exterminator will evaluate the situation and will recommend the correct protocol for you.  Using a licensed NY Exterminator is recommended, due to the various product regulations that are constantly changing.  A licensed exterminator is required by law to attend continuing education classes to maintain his or her license and will understand the safest and most effective way to treat your home or building.  In cases where the infestation affects a commercial food preparation space the products recommended for use may be different depending on regulatory statutes and product labels for public safety.
  • Maintenance
    • This is where many cockroach treatments fail.  Many residents or building owners will call in an exterminator to treat for a cockroach infestation, and upon finding the results of the clean-out (remember, 95% of the cockroach infestation is targeted for elimination during the initial service), will enter into a false sense of security upon finding that the cockroach activity seems to be gone.  What is happening during this time, however, is the remaining 5% of the cockroach infestation within the cracks and voids are still present.  As the nymphs develop, they eventually emerge, and the problem seems to resurface once again.  This ends up causing more stress, money, and anxiety for all involved.  So my recommendation is, stick with your maintenance program to be assured the cockroach infestation has been effectively exterminated.  Then, you can go back to the simple steps of Prevention, Sanitation, and Inspection.
Interesting facts about the German Cockroach
  • Three life stages: egg, nymph, adult
  • The German cockroach produces an odorous secretion.  This secretion can affect food flavor.
  • At high level infestations, the odorous secretion from German cockroaches is detectable in the general area of the infestation
  • Known pathogens carried by cockroaches
    • Salmonella
    • E. coli
    • These pathogens are dispersed throughout the area of infestation through the cockroach saliva, feces, and molted skins
  • Illnesses linked to the German cockroach
    • food poisoning
    • dysentery
    • diarrhea
  • Allergic reactions caused by the German cockroach
    • skin rash
    • watery eyes
    • sneezing
    • nasal congestion
    • asthma
  • Cockroaches are active at night and remain concealed within cracks, crevices, and voids during the day.  Unless the population is overcrowded, whereby they may be seen during the day.  Whenever cockroaches are spotted during daytime it is a potential sign that a significant cockroach infestation exists nearby.
  • A cockroach can survive long periods of time without food or water
  • German cockroaches are commonly referred to as "waterbugs"

An old cockroach joke although it may be debated that there may be some truth in this -
Q:  What are the only things that would survive a nuclear bomb?
A:  Cockroaches and a fruit cake, and the cockroaches would starve.

-Steve Spinelli
NYC Cockroach Exterminator
Titanium Laboratories, Inc.

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