Patterns of aggregation behaviour in six species of cockroach: comparing two experimental approaches
Abstract
Cockroaches (Blattaria) are considered universally gregarious insects. In this study, we tested the hypothesis that even related species and / or males and females of the same species may exhibit different aggregation patterns.We compared aggregation behaviour in six cockroach species belonging to three groups: Eublaberus, Blaberus, and Gromphadorhina-Princisia (all Blaberidae).
For comparison, binary choice and free aggregation arena tests were used. The results revealed that blaberid clades clearly differed in their aggregation patterns.
Females of Eublaberus species aggregated, whereas only a low aggregation tendency was recorded in conspecific males. Both sexes of Blaberus species aggregated, especially when tested in the arena.
The Madagascar hissing cockroaches of the Gromphadorhina- Princisia clade are not gregarious – the aggregation tendency was entirely absent in males of the two species studied and in females of Princisia vanwaerebeki van Herrewege.