We are constantly amazed and in awe of the dynamic aspects of the ecological systems found in nature. The world around us provides unlimited opportunities to discover and learn about the nature of our planet. Scientists have discovered the evolution of a new breed of termite, one that is quickly spreading across Florida and altering the genetic lineage of the native species here.
The Asian (C. gestroi) and Formosan (C. formosanus) subterranean termite species are producing hundreds of thousands of winged males and females (known as alates), which are in turn creating hybrid colonies, as reported by University of Florida researchers. These two species are particularly active in warm climates, and hybrid colonies could prove even more disastrous for homeowners.
According to University of Florida Entomology Professor Nan-Yao “They are the two most destructive termite species in the world,” He goes on to state that “The common name for Formosan subterranean termite in China and Japan is ‘house termite’ as it can literally bring down a house or roof as they chew through the supporting beams.”
There have been few studies regarding hybridization in termites and these have mostly described gene flow among populations of subspecies of these insects. Regarded as a class of invasive species, it is scientifically curious that they can produce viable offspring despite low levels of genetic diversity. It is speculated that both C. gestroi and C. formosanus were introduced in south Florida within the past 30 years, allowing for genetic mutations to develop across cycles of inbreeding resulting in a relative absence of genetic diversity in the native populations.
Due to the fertile nature of Florida’s subtropical ecosystem, the continuous spread of exotic termites is inevitable. Studies have shown that climate change can directly shift the habitat range zones and the timing of reproduction of multiple species because of alterations of environmental conditions. Hybridization in animals has been observed as a consequence of shifts in species distributions due to climate change. The unusually warm 2013 and 2014 winters (5th and 10th warmest winter on record) with successive cold fronts in the region (Source: NOAA) may have allowed for a wide overlap of the termite species dispersal flight seasons. In various meteorological prediction models, data trends show that these historically non typical weather patterns will occur with higher frequency in the near future. With the C. gestroi range predicted to move further north, simultaneous swarms may become a common occurrence.
The documented case of introgressive hybridization in fire ants (Solenopsis) in the Southern United States may serve as a cautionary tale, and the establishment of a hybridized termite population in south Florida with continuous gene flow between the two species remains a possibility. Both species have been established in Hawaii and Taiwan for a longer time, but hybridization has not been documented yet. The opportunity for C. formosanus and C. gestroi to hybridize may be unique to south Florida due to particular environmental cues and overlapping swarming seasons, but monitoring the dispersal flights in Hawaii and Taiwan would provide insight into the possibility of interspecies mating in all three locations.
Currently, it is not known if a hybrid colony can produce fertile and fully functional alates for maintaining hybrid populations and for possible introgressive hybridization back into the Formosian and Asian populations. Because of the long life cycle of termites, it may take from 5 to 8 years before colonies mature in the laboratory and in the field, which would enable researchers to confirm the fertility of the current generation. With so little study regarding the minutia of behaviors inherent of termites and the currently unknown mutations among the hybrid alates and soldiers from mature native colonies, it may take several years before the hybridization could be effectively monitored and confirmed in the field. Typically, mature colonies can contain millions of individuals and live up to 20 years. Even in the absence of new generation fertility, the persistence and establishment of hybrid colonies in urban environments would still pose a threat to building and structures in the sunshine state.