Pacific Dampwood Termite

Zootermopsis angusticollis — the Pacific dampwood termite — is the LARGEST TERMITE in North America and one of about 20 species in family Archotermopsidae (the dampwood termites — an evolutionarily ANCIENT termite lineage that includes some of the most basal living termites). The species is restricted to the PACIFIC NORTHWEST coastal regions of North America (British Columbia, Washington, Oregon, northern California) — a geographic distribution defined by the cool moist climate and abundant dead conifer wood that the species requires. Workers and soldiers reach 12-25 mm body length, with the species' diagnostic features: substantially larger than other NA termite species, brown body coloration, and (in soldiers) MASSIVE ELONGATED MANDIBLES used for colony defense. The species is one of the most cited examples of EARLY TERMITE EVOLUTION in modern termite biology research. Family Archotermopsidae includes some of the most BASAL LIVING TERMITES (only 4 living species in the genus Zootermopsis — Z. angusticollis, Z. nevadensis, Z. laticeps, and Z. dollatus — represent a small relictual lineage closely related to the common ancestor of all modern termites). Zootermopsis colonies retain features of EARLY TERMITE EVOLUTION that have been LOST in the more derived termite families: SMALL COLONIES (typically 100-1000 individuals — much smaller than the millions-strong colonies of more derived termite families), NO MORPHOLOGICALLY DISTINCT WORKER CASTE (the 'pseudergates' that perform worker tasks are simply JUVENILE TERMITES that retain reproductive potential — pseudergates can develop into reproductives, soldiers, or stay as worker-equivalents depending on colony needs; in contrast, more derived termite families have morphologically distinct sterile worker castes that cannot reproduce), and DEPENDENCE ON SYMBIOTIC PROTOZOA in the gut for cellulose digestion (a primitive characteristic shared with cockroaches — the closest living relatives of termites). The species nests inside DAMP DECAYING WOOD — typically in fallen Douglas fir logs, Western red cedar logs, and other downed Pacific Northwest conifer wood. The species cannot survive in dry wood (unlike the drywood termites Cryptotermes that infest dry building lumber) and cannot construct subterranean galleries (unlike the subterranean termites Reticulitermes — already in the Wild Files as eastern-subterranean-termite). Damage in human structures: Pacific dampwood termites occasionally infest building lumber that has prolonged moisture exposure (especially in coastal Pacific Northwest construction with persistent leaks, ground contact, or chronic dampness), causing significant structural damage to wet wood. The species is the focus of major Pacific Northwest structural pest management research and is a flagship species of NA termite biology. The species is harmless to humans (no bite, no sting — soldier mandibles are used only for colony defense against arthropod predators).