Pseudomicrotermes alboniger Wasmann, 1911 白黑伪小白蚁

Morphology

The description below is paraphrased from the original or a later revision, by caste; the source is cited at the end.

Diagnostic characters

A new genus established by Holmgren 1912 with a single species, Pseudomicrotermes alboniger (Wasm.), from Congo; a synonym in part is Mirotermes (Wasmann 1911). It was formerly placed in Microtermes and was separated because morphological examination showed its similarity to Microtermes to be merely one of habit; according to Holmgren's comparison table the alate of this genus is 'very small' with a very large head, far wider than the pronotum, and the soldier head is rectangular and far longer than wide, differing from Microtermes in the length of the clypeal base, the length/width ratio of the labrum, the mandibular dentition and the wing venation (presence or absence of an accessory vein and of a reticulation). The soldier labrum is lanceolate, more than twice as long as wide; the mandibles are blade-like and curved, not concave on the outer margin at the base; there are 13–14 antennal segments; the cerci are unusually long; there are no styli.

Alate

Very small. The head is very large, fairly strongly raised, thick and slightly narrowed anteriorly. The compound eyes are medium-sized and flat. The ocelli are small, almost no more than their own diameter from the compound eyes, directed fully laterally, their inner margins slightly raised. The frontal gland pore is far back, with a dark spot in the middle. The transverse band is very long. The base of the clypeus is short, far less than half its width and slightly raised, its posterior margin slightly concave and its anterior margin straight. The labrum is about as wide as long. The apical tooth of the mandibles is slightly swollen. There are 16 antennal segments, thickening towards the apex. The pronotum is fairly small, its anterior lobe incurved and its anterior margin concave; the posterior margin is concave. The posterior parts of the meso- and metanota are slightly pointed and rectangularly emarginate. The forewing scale is slightly larger than the hindwing scale. The wing membrane is transparent with very fine spine-like points and without a reticulation; the veins are very indistinct; the media lies close to the cubitus and appears to branch only very weakly (simple?); there are about 10 cubital veins. The abdomen is white. The fore tibia bears 3 apical spurs, the mid and hind tibiae only 2 each. The penultimate tarsomere is extended into a slender projection. The cerci are fairly long. There are no styli.

Soldier

The head is rectangular with rounded corners, far longer than wide, and thick. The frons is slightly inclined. The frontal gland pore lies on the horizontal part of the head, near the edge of the inclined part. The labrum is lanceolate, more than twice as long as wide, with a small transparent apex behind which a few setae arise. The mandibles are blade-like and curved, not concave on the outer margin at the base. The left mandible has one or two lobed basal teeth and three very small but sharp teeth in the middle; the apex is weak and minutely saw-like. The base of the right mandible has two small teeth, and its middle bears only a tooth-like blunt dilation. There are 13–14 antennal segments, thickening towards the apex. The pronotum is small and saddle-shaped, with a large anterior lobe and a deeply concave anterior margin. The cerci are unusually long. There are no styli.

Worker

The head is broadly oval, longer than wide. The frontal gland pore is fairly far back. The base of the clypeus is slightly shorter than half its width, its posterior margin fairly strongly convex and its anterior margin slightly concave. The mandibles are as in the alate. There are 15–16 antennal segments. The pronotum is saddle-shaped with a deeply concave anterior margin. The cerci are long. There are no styli.

This genus is monotypic, containing only this species; the following is the genus-level description based on the original literature; species-level measurements and intraspecific variation are given in the original.