Termite’s royal cradle: does colony foundation success differ between two subterranean species?

Abstract

Colony foundation modes play a key role in social insect societies as they strongly impact colony survival. In subterranean termites, we do not yet know which factors most influence the early stages of colony foundation since studies on the topic are scarce. In the present study, we examined how variation in life-history traits can influence colony foundation success in two European termite species: Reticulitermes grassei, an indigenous, and R. flavipes, an invasive. We conducted an experiment in which we observed the development of colonies founded by 165 royal pairs on a weekly basis over a 6-month period. Several key results emerged: (1) survival rates of royal pairs were lower in R. grassei; (2) R. grassei pairs laid fewer eggs; and (3) all castes contained fewer individuals in R. grassei colonies, but (4) their timing of appearance are similar for both species. Overall, R. grassei pairs seemed less robust and produced fewer offspring. To our knowledge, our study is the first to describe the foundation of R. grassei incipient colonies in detail over a 6-month period. We also discovered new information about R. flavipes’ colony foundation. The data suggest that the two species have different levels of colony foundation success, resulting in differences in colony development. This finding could help explain the invasiveness of R. flavipes. Our study contribute to our understanding of the spread of two termite pest species and shed light on critical steps in the colony foundation process.