the name says, this is said to be the most common cockroach in the U.K.
but there are differences of opinion about this, suffice to say there
are plenty of these about and as I said earlier, they are found in areas
of high temperature such as kitchens, laundry's and hospitals etc.
As you can see from the picture below the male has wings, though he
can't fly, and the female has only vestigial wings stubs, the picture
above is a female. These are wings which have devolved over the
millennia as the female never flies, so identification of the sexes
in this species is quite easy, if you're into that sort of thing. A
few facts below will bring home the need for control of this species
This species is dark brown to black
in color. Females are 1 to 1-1/2 inches long and have only rudimentary
wings reduced to small lobes. Males are a little shorter than females
and have fully developed wings which don't extend to the end of the
abdomen. A female will carry her ootheca for about 30 hours before she
drops or attaches it to a protective surface near a food supply. The
average female will produce 8 capsules, each having 16 eggs which hatch
in about 44 days.
This species is less wary and more sluggish
than other common cockroaches. It may enter the home in food packages
and laundry, or merely come in under the door or through air ducts or
ventilators. It's common in sewers, utility chases, in dark, damp basements,
and is known to climb water pipes to upper floors in blocks of flats.
This is a notably gregarious species, commonly being found in large
few facts :-
- They are 25-30mm long.
- They are dark brown to black.
- Wings are undeveloped in the
female, and only cover 3/4 of the length of the abdomen in the male,
this can be seen in the picture below.
- The female will produce 5-10
oothecae (egg cases) in her life time.
- There are 16 eggs inside the
egg case (Oothecae). Phew.! imagine if all that lot survived.
- The hatching time of the eggs
is about 2 months.
- The nymph, when it hatches,
will moult up to 10 times before it reaches adulthood.
- The development of the nymph
can take up to 9 months, but can be as little as 5 months, then they
too are off laying.
do we worry about cockroaches? because
there is no clear cut evidence to link them to disease outbreaks.
they have been found to be carrying a number of diseases, mainly because
of the areas that they frequent such as sewers, heating ducts, waste
disposals etc. A few are listed below:-
do I know that I have cockroaches?
- Mycobacterium tuberculosis
- Entamoeba histolytica
- Escherichia coli
- Ancylostoma spp. Human
and Dog Hookworms
- Taenia sp.
you know when you come in from the pub half drunk and you go into the
kitchen about two in the morning and the floor moves underfoot and tends
to make a crunching sound.....? Well then you've probably got
infestation in the home is quite rare these days unless you have been
unlucky bringing one in on say a box of produce. In the old days,
not so long ago, a lot of people used to burn coke on their fires.
Coke is made in a coking plant where coal is heated, in the absence
of air, and degassed. At the end of the process, the resulting
product (Coke) is drenched with water to cool it down hence we get very
hot and steamy conditions which are ideal for cockroaches. Cockroaches
lay egg cases (Oothecae) and when the coke was bagged so were the Oothecae.
Consequently when the coke was delivered, so were the Oothecae.
Infestations used to live behind the old ranges that people used to
have in their back parlours or kitchens which these days a lot of people
have removed and in any case coke isn't a common fuel now.
- This is liquid excreta produced by cockroaches when there is plenty
of water about they are usually brown and much bigger than the marks
left by a fly and are numerous near the habourages. Below is an old
black and white picture of German cockroaches and the faecal marks.
pellets - These tend to be found when there isn't much water about
and look a bit like mouse droppings, but they are only 2 mm long
and brown to black in colour.
(Oothecae) - These can some times be seen if the main breeding
area is found. Some examples of Oothecae can be seen below:-
if you come downstairs in the middle of the night and the floor
crunches then you have live insects this being another indicator.
if you're good, find cast nymphal skins. You need eyes like
a hawk unless there are loads about.
there is a smell, don't ask me to describe it other than it is
a roachy smell. You need to smell it to know it.
OK! so what
can I do.....in a nutshell, you can't do nowt (that's nothing in southern
terms). The only way to possibly cure cockroaches is to call
in a pest control company, who knows what they are doing. Curing
the problem means finding the breeding areas, if they are accessible,
and also treatment with insecticides. Making sure that a residual
insecticide is kept active so that any nymphs hatching out do so straight
onto an insecticidal surface. In short Guys and Gals, it is
going to cost you a bit of cash, so just hope and pray that you don't
For Pest control
chaps there is a detailed explanation of cockroach control
ootheca holding 16 eggs/nymphs
to main Cockroach page