FAMILIES OF ISOPTERA OF BRITISH COLUMBIA

by
R. A. Cannings and G. G. E. Scudder 
Copyright © 2005 - All rights reserved

Key to Families of Isoptera

1. Head with 2 ocelli in sexual forms; cerci 2-segmented; basal tarsomeres undivided, the tarsi clearly 4-segmented .....................................................2

- Head without ocelli; cerci 4 or 5-segmented; basal tarsomeres partially divided so that tarsi can appear to be 5-segmented from some angles .................................................................................................Termopsidae

2. Sexual forms with a "fontonelle" (mid-dorsal "pore" between eyes); wings, if present, without anterior oblique veins; soldiers with virtually untoothed (even if serrate) jaws; true worker caste developed............................ Rhinotermitidae

- All forms without a "fontonelle"; wings, if present, with 3 or more heavy, oblique veins in anterior field; soldiers with toothed jaws; true worker caste lacking. ...............................................................................................Kalotermitidae

 

Description of Families

Family Kalotermitidae (drywood and powderpost termites)

The Kalotermitidae, like the Termopsidae, is a primitive family lacking a worker caste. The cerci are short, with only two segments. The flying adults have ocelli and the antennae usually have fewer than 20 segments (this is true for the single species recorded in B.C.). There are about 350 named species living in warm climates and many more probably remain to be discovered, but none is native to Canada. Most species feed on dry wood well away from the soil, although some genera do attack damp rotten wood and tree roots. Because many species do not require a moist environment, members of this family have traveled with humans across the world, and some have successfully immigrated far from their native homes.

Cryptotermes brevis (Walker) has established colonies in at least two B.C. locations: in the Zoology Department at the University of B.C. in Vancouver, a colony lived for decades in the wood panels of a laboratory cupboard and, at Port McNeill, a wooden case imported from Peru in 1978 supported a colony of all castes for a number of years . This species also was introduced in eastern North America and has appeared from Florida to Texas, north to Ontario. In its northern outposts Cryptotermes lives only indoors; it attacks buildings, furniture, books and dry goods.

 

Family Rhinotermitidae (subterranean termites)

This is a more evolved family than the Termopsidae – there is a true worker caste, the cerci have two segments and the tarsi four, and the reproductives have two ocelli, a pale depression between the eyes (fontanelle), and reduced venation in the wings. Colonies develop in moist underground places -- in buried wood or in wood lying on the ground. The termites can work in wood unassociated with the soil, but then build earthen shelter tubes between the soil and wood to maintain the soil moisture throughout the galleries.

There are 14 living genera and 160 species of Subterranean Termites; one genus, Reticulotermes, lives in Canada and B.C. Reticulotermes hesperus (Banks), the Western Subterranean Termite, is the only species in B.C. It ranges south to California. In B.C. it lives mostly on the south coast and in the dry interior, and there are reports as far north as the Cariboo. The soldiers and workers are white to yellow, 5 to 6 mm long. The head of the soldier is yellow to black and distinctively long and narrow, about twice as long as wide; there are no teeth on the long mandibles. The reproductives are dark brown; the wings are up to 9.5 mm long and are brown-grey. Colonies can produce thousands of individuals and supplementary queens may develop, allowing the colony to grow rapidly and even subdivide. Such colony formation may be more common than the establishment of new colonies by winged pairs. R. hesperus emerges in mass flights; in the southern parts of its range it swarms in the fall, but in the north, spring swarming also occurs.

Family Termopsidae (dampwood termites)

Adults have three or four heavy veins along the front edge of the wing, the cerci have five or six segments and the antennae have 20 or more segments. The tibiae are spined and there is no fontanelle. Soldiers have toothed mandibles and the cerci have three or more segments.

There is no worker caste; immature soldiers and reproductives do the work of the colony. Dampwood termites normally live in coniferous woods in dead trees, stumps and logs, especially those with fungal rot that allows easy entry. Although the wood they live in and feed on does not need to be in contact with the ground, it must contain some moisture. Man-made wooden structures in contact with the ground or with a continual source of dampness are attractive to these termites. They do not tunnel through the soil and do not build shelter tubes.

There are only five living genera in the Termopsidae, which are among the most primitive of living termites. The family is sometimes placed in the Hodotermitidae. Zootermopsis is a strictly North American genus with three species, two in B.C. Zootermopsis angusticollis (Hagen), the Pacific Dampwood Termite, is common on the coast north at least to the Queen Charlotte Islands and Prince Rupert. It ranges inland into the B.C. interior and south to Baja California. The soldiers are 15 to 20 mm long, creamy brown with a dark brown head and black mandibles; the sides of the head are concave. Reproductives are yellow to chestnut-brown with pale brown or grey-brown wings and, including the wings, reach 25 mm in length. Z. angusticollis flies on warm evenings from July to September. It is especially noticeable along ocean beaches where it emerges from beach logs. Z. nevadensis (Hagen), the Dark Dampwood Termite, is darker brown and smaller, the winged forms usually less than 20 mm long. The sides of the head in soldiers are straight and parallel. The species ranges from the coast and interior of southern B.C. to Idaho and northern California. It can tolerate cooler and drier habitats than Z. angusticollis and can live at altitudes up to 1800 metres.