BEHAVIOURAL CHARACTERISTICS OF THE GERMAN COCKROACH, BLATTELLA GERMANICA (L.)

Abstract:
Observations of the nocturnal behaviour of the German cockroach, Blattella germanica, were carried out using single or mixed populations of males, gravid females, ungravid females and nymphs. The results of these studies can be summarised as follows: 1. The proportion of cockroaches present in a feeding and activity area was nearly constant in the same sex or maturity groups, irrespective of the numbers of individuals released in an adjoining 'hiding' area. 2. Adult males were very active and they did not concentrate on the feeding site, but distributed widely in the activity area. 3. Under any of the experimental conditions, only a few gravid females came to the feeding site from the refuge area during the observation periods, and ungravid adult females were much more active than gravid ones. In a separate field study of capturing cockroaches by setting adhesive traps in a restaurant, the proportion of adult males, ungravid females, and gravid females was 63%, 30%, 7%, respectively. The results also . indicated differences in moving activity of these groups.