Living With Cockroaches

The Dictyoptera, the order containing the cockroaches, has species that exhibit varying degrees of social behavior from loosely organized social “herds” of some cockroaches to eusociality of termites complete with castes and division of labor. The domestic German Cockroach, Blattella germanica, and the peridomestic American Cockroach, Periplaneta americana, live together in herds. These herds are more than collections of independent individuals. The individuals have important social interactions. The social interactions of German and American cockroaches are reviewed by Lihoreau and colleagues in the Journal, Insectes Sociaux.

American Cockroaches
Photo: Purdue Extension

If given a choice between two or more shelters, German Cockroaches or American Cockroaches will aggregate in a single shelter during the light phase of the light-dark cycle. These cockroaches also demonstrate collective selection of feeding sites. These cockroaches grow and develop better in groups than as individuals. Rearing these cockroaches as individuals leads to “isolation syndrome” characterized by slower development time and delayed maturation of the reproductive system. Isolated individuals even exhibit “behavioral disorders”.

American or German Cockroaches that are unrelated by parentage will form “mixed-family herds” of overlapping generations. Within these herds, individuals have some ability to recognize close kin that enables them to choose less closely related mates and avoid inbreeding. A catalogue of behavioral interactions has led to the realization that social interactions are critical to the biology and success of these species.

A knowledge of social behaviors of pest species of cockroach can help us develop better strategies for controlling them. Understanding how individuals interact in simple societies can lead to insights into more complex societies and complex social behavior and even have relevance to human societies.

*Insect. Soc. (2012) 59:445–452 DOI 10.1007/s00040-012-0234-x