Experimental studies on harbouring behaviour of the adult German cockroach, Blattella germanica (1)

Abstract

The harbouring behaviour of adult German cockroaches was studied experimentally using slit shelter that its utilizable space was 10cm×10cm×0.5cm and it was stood vertically on bottom of a test container. The results of the experiments can be summarized as follows.
1. In case of only male adult given two shelters, its congregation was spaced-out gregariousness that the mode in the frequency distribution of nearest neighbour distance (NND; mm) was 10 to 15mm being approximately equal to the body length of test insects, and the cognitive distances among test insects had depended on the length of antennae. The distribution of male in shelters was generally equal, and it was identical kept with female. But, when single shelter was given, male had preferred the harbour and the congregation to the maintenance of NND.
2. In case of only female with egg capsule, in spite of number of shelters and tesed insects, female adult have shown peculiar harbouring behaviour that crowded in the low site of the shelter.
3. When male and female were lived in the same container in the experiment with two shelters, spaced-out gregariousness of male above-mentioned did not occur at all that perhaps originated from some factors being related to an existence of female.