Ovipositional Site Preferences and Characteristics of the American cockroach, Periplaneta americana (L.) (Blattodea: Blattidae), and Brownbanded cockroach, Supella longipalpa (Fabricius) (Blattodea: Ectobiidae)

Abstract

Cockroaches are major pests in much of the United States, with the U.S. Census 2019 American Housing Survey reporting 14 million households with infestations. Oviposition substrate preference has been studied in various cockroach species. American cockroach, Periplaneta americana (L.) (Blattodea: Blattidae), and brownbanded cockroach, Supella longipalpa (Fab.) (Blattodea: Ectobiidae), have both been associated with medically significant pathogens and are peridomestic and domestic pest species respectively. Oviposition substrate preference has been studied in various cockroach species. However, there has been variability in substrates and bioassay methods without consideration for how different variables may affect choice. The aim of this thesis was to use similar methods to test how a variety of variables affected oviposition site selection in two cockroach species of different families. The aim of this study was to compare how oviposition site substrate preferences in American and brownbanded cockroaches differ in varying conditions. Using adult females of both species, we performed multiple-choice bioassays under both light and dark conditions at room temperature (~22C). In these bioassays, one gravid female cockroach was placed into a sweater box with either five indoor substrates (carpet, extruded polystyrene foam insulation, paperboard, painted plywood, and unpainted plywood) or five outdoor substrates (gravel, sand, soil, tree-bark, and terracotta pottery). Cockroaches were given 36 hours to oviposit in the substrate of their choice. Further experiments were performed to clarify preference in American cockroaches (removal of Expanded Polystyrene Foam (XPS) as an option and comparison of two forms of XPS) due to strong preference in light (90%) and dark (60%) conditions for XPS, and oviposition site selection process in both. Outdoor results showed a preference for sand, soil, and bark in both species. Indoor results showed a preference for unpainted wood in brownbanded cockroaches and XPS in American cockroaches. Then, ethograms were constructed using continuous sampling to generate time activity budgets and transition matrixes of behaviors associated with oviposition site selection.