Giant Australian termite

Mastotermes darwiniensis

FAMILY

Mastotermitidae

TAXONOMY

Mastotermes darwiniensis Froggatt, 1896, Port Darwin, West Australia.

OTHER COMMON NAMES

None known.

PHYSICAL CHARACTERISTICS

Large: alates up to 1.4 in (35 mm) with wings, 2 in (50 mm) wingspan; soldiers 0.45–0.5 in (11.5–13 mm); workers 0.4 in–0.45 in (10–11.5 mm). Only termite whose winged alates possess anal lobe in hind wing; tarsi have five segments, females have short blattoidlike ovipositor with ventral valves, long enough to overlap the dorsal valves; eggs laid in ootheca. Soldiers have round reddish heads with relatively stout short mandibles, long apical teeth; right mandible has two well-defined marginal teeth, but in left mandible only first marginal tooth is well defined, second and third are indistinct. Soldiers and workers have unique coxal armature, or flange, on front legs, and rows of small opposable teeth on femora and tibia, unique leg characters in this family.

DISTRIBUTION

Once cosmopolitan (as indicated by fossils), now confined to tropical northern Australia and nearby islands.

HABITAT

Xylophagous and subterranean, feeds on logs, dead standing trees, and surface wood. Also known to girdle live trees, including commercial tree plantings, then feed on killed trees.

BEHAVIOR

Meso-eusocial. Little is known aside from feeding ecology and reproductive biology.

FEEDING ECOLOGY AND DIET

Independently evolved subterranean foraging habits and ability to build mud shelter tubes to access wood above ground level. Simple nest chambers of several tiers of thin-walled carton cells usually in bole of tree or stump, near or below ground level. Colonies may exceed 1 million individuals and forage over 328 ft (100 m).

REPRODUCTIVE BIOLOGY

Workers frequently transform into ergatoid reproductives that replace primary reproductives when colonies are orphaned, but more typically develop as supplementary reproductives and form new colonies by budding off from parent colonies. Most reproduction probably by neotenic ergatoid reproductives.

CONSERVATION STATUS

Not threatened.

SIGNIFICANCE TO HUMANS

Of phylogenetic interest because of status as a monotypic family, exhibits unique morphological characters that place it as most basal termite and possibly most basal extant species of Dictyopterid. Serious structural, forest, and agricultural pest; most destructive termite in tropical northern Australia; damaging timber in buildings, bridges, poles, fence posts, railway sleepers, living trees, and crops. Also feeds on many host tree species, including live trees, and attacks plantations and crops such as sugar cane. However, its large body, large colony size, and wide diet make it an excellent candidate for beneficial termiticulture on cellulosic wastes.