Ongoing human-mediated spread and hybridization of two major invasive termite species

Human-mediated biological invasions can lead to introgressive
hybridization events between lineages that have evolved independently,
with potential for evolutionary, ecological, economic, and social impacts.
This study provides evidence for the ongoing spread and hybridization
between two major invasive and destructive termite pest species,
Coptotermes gestroi and C. formosanus, in Florida. Heterospecific
courtship behavior between alates (winged reproductive caste) of the two
species has led to the establishment of F1 hybrid colonies in the field,
which have matured and produced F1 hybrid alates. Laboratory backcross
attempts confirmed the possibility for F1 hybrid female alates to
establish viable F2 colonies with males of either parental species. With
the recent documentation of introgressive hybridization between the two
species in Taiwan, the current study confirms its independent occurrence
in Florida, demonstrating that both Coptotermes species can hybridize in
areas where their distributions overlap. In Florida, the proximity of
field-established hybrid colonies to the large leisure boat industry
implies that Florida populations of C. gestroi, C. formosanus, and their
hybrids will continue to serve as a bridgehead source of propagules for
further dispersal beyond their current distribution, with a potential for
F1 Hybrids to spread outside of Florida.