Schedorhinotermes intermedius

Schedorhinotermes intermedius is a widespread subterranean termite native to eastern Australia. It is considered a major pest species.

Identification
astes of this species may be easily mistaken with S. actuosus, S. actuosus, S. breinli and S. seculus.

S. intermedius has a monomorphic true worker caste, a dimorphic soldier caste and a single reproductive imago caste. Typical of the subfamily Rhinotermitinae, the soldier caste has a labrum modified as a brush. In Schedorhinotermes in particular the labrum is not very large in length and the mandibles of the minors are still rather well developed despite albeit small.

Schedorhinotermes be distinguished from Parrhinotermes due to the possession of minor soldiers, which often out number the majors.

This species is rather typical of Australian Schedorhinotermes, imagoes posses a truncated or swollen postclypeus, workers lack any pigment and have large heads proportional to their body, and the major soldiers are typically not much larger than the workers.

Websites with ID material

PaDIL:Subterranean termite

Major Soldier: - 5.0-7.5mm in length; Bulbous head.

Minor Soldier: - 3.0-5.0mm in length (approx 2/3 length of major soldier); Narrower head, mandibles more slender; Labrums extend almost to the tip of the mandibles.

Distribution
S. intermedius is widely distributed on in Australia, however it is mainly coastal; occurs from Southeast Queensland to just south of Sydney. It is definitely not present in the Northern Territory.

Habitat

It is primarily a woodland species.

Nest
Like other subterranean termites, S. intermedius is not thought to make centralized nests and instead relies on a network of tunnels within the soil and/or uses logs as satellite nests.

S. intermedius has been found in dead and live wood of various sorts (structural timber, logs, stumps, dead, weakened or live root crown of trees, and even occasionally in the trees themselves), other termite mounds and of course soil.

Developmental pathways
In Schedorhinotermes, workers and soldiers are female, males only are produced for swarming. This rule applies to S. intermedius as well. It is unknown why this is the case but the sterile castes are not produced via parthenogenesis.

Biology
The number of major soldiers determines the health of the colony.

Swarming
In Sydney, swarming occurs during the winter, around December.

Colony founding
Colonies are founded under or within wood, particularly logs.

Defense
Like other members of Rhinotermitinae, Schedorhinotermes have a modified labrum (termed, daubing brush) that applies the contents excreted from the fontanelle onto the enemy via physical contact. Despite the well developed mandibles of both castes the chemicals employed do not need a wound in order to affect the victim.

Soldiers bang their heads when alarmed.

See: Termite Defense: 101

Foraging
S. intermedius forages at night. This species builds mud tubes in order to get to their food source over exposed areas.

Diet
S. intermedius feeds on wood.

Interactions with other organisms
Termitophiles

Like other members of Rhinotermitinae, S. intermedius boasts a wide range of termitophiles living within its galleries.

Interactions with humans
S. ntermedius is regarded as serious pest both agriculturally and structurally, being considered second to that of Coptotermes in terms of damage.

It has the distinctive habit of eating around nails embedded in structural timber.

Castes
Photo sources:

Nomenclature
From: Gerald F. Hill in Australian Rhinotermes (Isoptera). Proceedings of the Royal Society of Victoria (n.s.) 45 (1) pp. 1-6.

imago Colour: Yellow ochre above; antennae, palpi, postclypeus and under surface somewhat paler; radius and radial sector yellowish-brown, wing membrane hyaline.

Head: Viewed from above rounded, semi-circular behind the eyes, frons depressed and furrowed. Eyes large and prominent. Ocelli large, broadly oval. Postclypeus short, strongly convex, truncate in front; anteclypeus short, hardly projecting beyond the postclypeus. Labrum short and wide, widest at the base, narrowed to the rounded apex. Antennae with 20 segments; 1st segment cylindrical, a little less than twice as long as 2nd; 2nd cylindrical, much narrower than 1st, as long as the 4th; 3rd about two thirds as long as 1st and as wide at the apex; 4th globose, a little narrower than 3rd; 5th - 19th increasing slightly in length progressively; 20th a little shorter and much narrower than 19th.

Thorax: Pronotum large, slightly narrower than head, anterior and posterior margins slightly sinuate anterolateral angles broadly rounded, sides slightly narrowed to the wide posterior margin, Posterior margin of mesonotum and metanontum broadly concave.

Wings: Forwing rather more than three times longer than wide; radius and radial sector distinct, the other veins and membrane hyaline; the median branches from the radial sector near the base of the stump, passes though the middle of wing at the suture and runs parallel with and near to the radial sector for a short distance before curing posteriorly; at the middle of the wing it passes through the anterior one-third, where the first of several branches occur, the anteriormost of which joins the margin below the apex. The cubitus runs above the middle of the wing before curving downwards to the posterior margin with which it junctions at the distal fourth of the wing. This vein has many long branches to the posterior margin. In the hindwing the median branches from the radial sector a little beyond the suture, and usually has many branches from its proximal half. The cubitus is generally similar to the t of the forewing. Forwing sclaes overlapping the basal half of those of the hindwings. Legs: Long and slender; tibiae and tarsi very hairy; tibial spurs 2 : 2 : 2.

soldier: 

Colour: Head light yellow, a little darker than remainder of insect; base of mandibles yellow-brown, apical half light ferruginous.

Head: Large, rounded behind, widest at the posterior one-third, narrowed to the base of the mandibles, with very few hairs. Mandibles large; the left with two large teeth in the apical half; the right one with one large tooth about the apical one-third, no small tooth between the former and base of mandible. Labrum extending to the base of the basal tooth on the left mandible, markedly widened about the basal third, thence narrowed to the widely emarginate anterior margin. Gula long and narrow, the narrowest part about one fifth the width of the head at this point, Antennae of 18 segments; 1st long and nearly cylindrical, 2nd about half as long as 1st; 3rd nearly always longer than 2nd, rarely equal or shorter; 4th smallest of all, the remaining segments monoliform, increasing in length progressively.

Thorax: Pronotum short and wide, with scanty long and short hairs, the anterior margin convex and sloping to the rather sharply narrowed anterolateral corners, the sides narrowed sharply to sinuate posterior margin.

Legs: Long and slender, the femore with few, the tarsi with many hairs; tibial spurs 2 : 2 : 2.

Abdomen: With scanty hairs.