Thermobia domestica - The Firebrat

Thermobia domestica is an insect discovered by American entomologist and paleontologist Alpheus Spring Packard in 1873. (Integrated Taxonomic Information System 2012)  Thermobia (Greek root "thermos" meaning hot) is found primarily in homes (domestica, root word from Latin "domus" meaning house) as a pest.  Historically, this heat-seeking critter was found around bakery ovens and fire stoves seeking starchy foodstuffs, which is where it earned the nickname "firebrat." (Adams 1933)

It's appearance is small, usually not reaching more than half an inch (~12mm) in length,  Firebratbut its impact can be large.  With a flat, elongated body and quick, agile movement, the Firebrat can occupy very small spaces and be difficult to catch.  These characteristics, coupled with its love for carbohydrates, mean it can get into book bindings and pry under wall paper to eat the starchy contents and cause a good deal of damage. (Davies 1988)

This wingless wonder is often confused with its close cousin the Silverfish, also from Order Thysanura, and is also prone to cause damage and vexation in the home.  Both species are considered "bristletails" (Greek "thysanos" meaning "tassel" and "oura" meaning "tail") and can be recognized by the plethora of hair-like bristles that cover their bodies. (Hickman et al. 2009)  Both are primitive insects with scaled exoskeletons that avoid disturbances by being active at night, but there are differences between the two.  Firebrats are usually brown in color with dark splotchy patterns, while Silverfish are uniformly gray or silver with more of a sheen on their bodies.  Silverfish prefer moderate temperatures with high humidity and Firebrats like high temperatures with moderate humidity. (Housman 2007) This could be an adaptation to avoid competition for a niche indoors or out.

Thermobia domestica is a curious creature with some interesting physical and behavioral characteristics.  It has the ability to not only move very quickly, but also in a lateral or sideways direction.  Firebrats are covered in iridescent scales which closely resemble those of a butterfly, and their antennae are longer than their bodies. (Sweetman 1938)  These guys come from an ancient lineage of the first insects virtually unchanged; they do not have wings because they were around before other insects adaptively developed them!  One of the oldest known insect fossils is a Thysanuran from the Triassic period (250-200 million years ago) found in the Ural Mountains. (Lanham 1964)  Perhaps what is most interesting about Thermobia is the fact that they perform a complex mating dance! 

The following video shows footage of the Firebrat's movements as well as great close-up images of its physical characteristics.

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