German cockroach – Blattella germanica
Silverfish - Lepisma saccharina
Key Features:
The adult is light brown in colour with two dark almost parallel longitudinal stripes on the pronotal shield,
The female is darker than the male and with a broader abdomen.
Both male and female adults are fully winged.
Early instar nymphs have a pale area centrally on the dorsal thorax,
Later instars have two dark longitudinal stripes on the pronotum.
Biology:
The ootheca is carried by the female until it is within 1-2 days of hatching.
Small 1st instar nymphs emerge from the ootheca and easily infest tiny cracks and crevices in the immediate area.
All the nymphal stages and the adults feed on the same type of food, making the establishment of an infestation extremely easy.
Prior to moulting, nymphs become immobile, remaining in harbourages.
Distribution:
Cosmopolitan.
Significance:
German cockroaches are found throughout buildings but show a preference for warm humid areas.
Adult size: 13-16 mm
Number of moults: 5-7
Development time: (Egg to adult) 1-3 months
Length of adult stage: 3-6 months
No of ootheca produced: Average 5
In female lifetime: Range 4-8
No of eggs produced: Average 30-40
per ootheca: Range 18-50
Number of moults: 5-7
Development time: (Egg to adult) 1-3 months
Length of adult stage: 3-6 months
No of ootheca produced: Average 5
In female lifetime: Range 4-8
No of eggs produced: Average 30-40
per ootheca: Range 18-50
They are good climbers, being able to climb vertical glass or tiled surfaces.
An infestation of these cockroaches can be quickly established once they have entered any premises.
This species is an extremely serious pest in many different types of premises ranging from hospitals to domestic houses.
