Genetic diversity and invasion history of the European subterranean termite Reticulitermes urbis (Blattodea, Termitoidae, Rhinotermitidae)

Evolutionary history of Nasutitermes kemneri (Termitidae, Nasutitermitinae), a termite from the South American diagonal of open formations

Little is known about the phylogeography of termites in the Neotropical region. Here, we explored the genetic patterns and phylogeographical processes in the evolutionary history of Nasutitermes kemneri, an endemic termite of the South American diagonal of open formations (DOF) formed by the Chaco, Cerrado, and Caatinga phytogeographic domains. We sampled 60 individuals across the three domains of the DOF, and using the mitochondrial genes 16S, COI, and COII, as well as the nuclear gene ITS, evaluated the genetic diversity and divergence time of the populations, along with their genetic structure. The results show a strong genetic and spatial structure within the samples, evidencing the existence of two well-differentiated genetic groups: the Northeastern and the Southwestern populations, which diverged about 2.5 Mya, during the Pliocene-Pleistocene boundary. The Northeastern population, which encompasses Caatinga and northern portions of Cerrado, has an intricate structure and seems to have suffered repetitive retraction-expansion events due to climactic fluctuations during the Quaternary. The Southwestern population, which ranges from central-south Cerrado to the northeast peripherical portions of the Chaco, displays a star-shaped haplotype structure, indicating that this region may have acted as a refugia during interglacial periods.

Globalization and the anthropogenic spread of invasive social insects

Social insects are among the worst invasive species and a better understanding of their anthropogenic spread is needed. I highlight recent research demonstrating that social insects have been dispersed since the early beginnings of globalized trade and in particular after the Industrial Revolution, following two waves of globalization. Many species have complex invasion histories, with multiple independent introduction events and frequent secondary spread. The major source and recipient regions differ markedly across ants, wasps, termites and bees, probably linked to their different introduction pathways. At a more local scale, anthropogenic factors such as irrigation, urbanization or the presence of railways facilitate invasions. In the future, social insect invasions could further accelerate due to intensifying global trade and novel introduction pathways.