Habitat use by cockroaches in kanuka-beech forest

Monthly live-trapping data show well-defined annual cycles of abundance in a mixed population of indigenous cockroach species. Seasonal changes in size and sex classes indicate movements both on tree trunks and on the ground, and differing patterns of habitat use by males and females. Summer population peaks are caused by dispersal from overwintering sites, particularly by the long-lived adults. Despite extensive co-occurrence of the species, there is evidence for microhabitat partitioning in the use of shelter sites, and also for the vertical stratification of nocturnal activities on vegetation. Analyses of crop contents show that they are opportunist and relatively unselective feeders. Food sources include fungus, wood, epiphylls, and arthropod material. Circumstantial evidence suggests that honeydew may also be important, but this is difficult to detect. Differences between species in the frequencies of food items correlate with differences in microhabitat.