The world’s most destructive termite species, Formosan subterranean termites (Coptotermes formosanus) and Asian subterranean termites (Coptotermes gestroi), were previously thought by scientists to be prevented from interbreeding due to their distinct, separate swarming seasons. However, with climate change and human activity, they have recently been observed to swarm simultaneously in South Florida.
Research published by a team of University of Florida entomologists in the journal PLOS ONE, now indicates not only an overlap of seasons where the two species are interbreeding; it also shows that male Asian termites may actually prefer to mate with Formosan females, increasing the risk of hybridization. According to Professor Nan-Yao Su, an entomology professor at the UF Fort Lauderdale Research and Education Center, this may be because the Formosan female may produce more mating pheromone than its Asian counterpart. In the laboratory, the Florida researchers are raising a hybrid colony that is growing twice as fast as same-species colonies, suggesting a potential for a vigorous “Super Termite” hybrid.
Although researchers have yet to determine whether this lab bred hybrid colony can actually reproduce, even sterile colonies can pose a danger. According to Su “because a termite colony can live up to 20 years with millions of individuals, the damaging potential of a hybrid colony remains a serious threat to homeowners”. Su warns that what makes the emergence of these highly vigorous hybridised colonies so alarming is that they’re reproducing at a rate that is more than twice as fast as the parent species. According to Thomas Chouvenc, research assistant to Su, “The establishment of hybrid termite populations is expected to result in dramatically increased damage to structures in the near future.”
And with the hybrid colonies reproducing at a much faster rate and growing to larger numbers, the possibility of them spreading is also much greater. Asian and Formosan termites already have a track record of this. The Formosan termite originated in China, but is now firmly entrenched in the southeastern U.S. Even more widespread are Asian termites, which have spread to Brazil and the Caribbean islands.
The Florida research paints a “sobering picture” warns Ed Vargo, professor of entomology at Texas A&M University. “You have the two most destructive subterranean termite species in the world, and here they are, brought together through human activity, being introduced together in a place where they’re not native, and they’re hybridizing.”
Not only does this present the obvious biosecurity threat to Australia, it also poses the wider possibility of existing local termite species interbreeding with the advent of changes to termite behaviour in response to human instigated climate and environmental changes.
You can read more using the following sources:
Thomas Chouvenc, Ericka E. Helmick, Nan-Yao Su. “Hybridization of Two Major Termite Invaders as a Consequence of Human Activity”. PLoS One, 2015.
University of Florida Institute of Food and Agricultural Sciences. “Two most destructive termite species forming superswarms in South Florida.” ScienceDaily, 25 March 2015.