Research advance of Coptotermes formosanus biology in recent 25 years

The Formosan subterranean termite, Coptotermes formosanus, is a wood-feeding pest widely distributed in subtropical and temperate regions of the world, mainly damaging various wooden structures and trees. Due to the massive economic losses and damage caused by C. formosanus, it has drawn significant academic attention in recent years. The understanding of C. formosanus biology is the basis for developing control methods. Here, we systematically reviewed papers about C. formosanus biology published since 2000. The global distribution of C. formosanus is caused by multiple introductions from East Asia and the bridgehead effect, and its suitable distribution range may expand due to global climate changes. C. formosanus behaviors such as foraging, tunneling, and trophallaxis closely associated with chemical control methods (i.e., baiting and chemical barrier) have been intensively researched. In addition, a series of semiochemicals with trail-following, aggregating, tunneling, and feeding-stimulant activities have been successfully identified and screened, providing new insights to lure and kill C. formosanus. Due to the immune response and behavioral resistance of C. formosanus against entomopathogens, the research on biological control of this termite has been stalled. However, technologies such as RNA interference are expected to suppress the disease resistance of C. formosanus and may bring new control technologies. In addition, C. formosanus has complex interactions with environmental microorganisms such as wood-decaying, blue-staining, and Trichoderma fungi, as well as gut microorganisms such as protozoan flagellates, bacteria, archaea, and viruses. C. formosanus has two independent but complementary cellulose degradation systems - the endogenous cellulose degradation system composed of cellulase produced by termites and the exogenous cellulose degradation system composed of symbiotic microorganisms. Its ability to efficiently degrade lignocellulose has important implications for biomass energy research.