[Size and distribution of a Blattella germanica population]

The abundance and dispersion of a selected genetic homogeneous and isolated population of Blattella germanica was observed by the method of dry incorporation of radioactive porcellain tracer. Under optimal conditions, a medium density of 130 individuals per cubicmetre volume was found. The fluctuations came to 50% from the middle value. The dispersion is unequal and depends as well on the requisites of the room as on the size and the quality of the existing aggregations. An interchange exists between the aggregations. In this respect males are more active than female cockroaches.