Description
Oriental (Blatta orientalis) and German (Baltella
germanica).
The Oriental and German cockroaches are the most common species
found in Northern Europe. They are occasionally found
together, but generally the German cockroach prefers warmer, humid
environments such as kitchens, laundries and other centrally heated
buildings, whereas the Oriental cockroach normally prefers less
humid areas such as cellars and drains. The adult Oriental
cockroach is dark brown/black and about 20 - 24 mm long. The
adult German cockroach is yellowish/light brown and is about 10 -
15 mm long.
Biology and Habitat
Oriental Cockroach
The female can produce up to five egg capsules at monthly
intervals, these capsules can contain up to 16 eggs. They are
deposited in or around a suitable food source and at about six to
ten weeks later, the nymphs emerge and over the next 6 - 18 months
progress through 7 - 10 moults before reaching maturity, the
process is reliant on the temperature and food supply. The
adult cockroach can live for up to six months.
German Cockroach
The adult female produces egg capsules which can contain up to
30 eggs, however in contrast to the Oriental cockroach, the German
cockroach carries the capsule, attached to her abdomen up until the
young nymph cockroaches are about to hatch from the eggs. The
time period is dependent on the temperature, but two to four weeks
is the normal time period. The nymphs then go through about
six to seven moults over a period of three to six months before
reaching sexual maturity, the adult can live for up to nine months
under the right conditions.
Importance
The Oriental cockroach is known to carry some pathogenic
bacteria, but direct disease transmission to humans is scarce.
The German cockroach is known to carry and spread various human
disease organisms and due to its habits of walking over and feeding
on putrefying waste materials, drinking at unsavoury water supplies
and then freely walking over food preparation areas, cutlery and
crockery and human food in its search for further food enables it
to spread disease organisms.
Control
A high standard of hygiene is very important in the treatment of
cockroaches. It is important to deny access to food and water
and harbourages in buildings or equipment. The use of bait
stations using a gel solution is fast becoming the number one
treatment. The other treatments available to the service
include the use of ULV space spray and wet sprays. Regular
treatments at weekly intervals may be required until an infestation
is brought under control.
Safety
All pesticides used by Bath & North East Somerset Council
are approved substances under the Control of Pesticides Regulations
1986 and are fully risk assessed.
