Why Are Eastern Subterranean Termites So Widely Distributed Within North America?
There exists around 45 documented termite species inhabiting the United States. Most of these species are native to North America, but several non-native species have established an invasive presence within the US as well. Although the two most destructive termite species in the world, Formosan and Asian subterranean termites, have become established in the US, their habitat is limited to the southern most states. These two species require hot tropical and subtropical climates in order to thrive, which makes them ill suited for establishing a wide distribution range within North America where the climate is relatively temperate. However, the North American native R. flavipes, or eastern subterranean termite, has adapted to surviving within colder climates. This termite species’ tolerance to colder climates has allowed it to establish a distribution range that covers the whole of the US as well as southern Canada. The abundance of eastern subterranean termites within North America makes this species the most destructive and economically important termite species within the US.
The termite family known as Rhinotermitidae is comprised of species that have the ability to adapt to colder climates, which explains their wide distribution within temperate zones. Of all Rhinotermitidae species, the eastern subterranean termite is the most cold tolerant, as no other termite species is capable of establishing a habitat as far north as where these termites are found. In fact, eastern subterranean termite colonies have been discovered thriving at latitudes located far north of their native North American habitat range.
Eastern subterranean termites are well established pests within Toronto, and at least one nature preserve in southern Canada contains their colonies. Researchers have discovered eastern subterranean termite colonies surviving within environments as cold as 32 degrees fahrenheit, and one study showed that these termites can briefly tolerate temperatures as low as 23 degrees fahrenheit. Another study found that eastern subterranean termites could survive being frozen within ice for brief periods, making them freeze-tolerant insects. A different study found that colonies of these termites could progressively acclimate to colder temperatures over time, thus explaining their continued northern migrations within Canada.
However, several other studies suggest that eastern subterranean termites are freeze-avoidant as opposed to freeze-resistant, as these termites may buffer themselves from cold weather by tunneling to lower depths beneath the ground. Whether eastern subterranean termites are freeze-resistant or freeze-avoidant, this species is still managing to migrate farther north from its known distribution range in North America.
Have you ever heard of a termite species that dwells within sub-arctic conditions?
