Cephalotermes rectangularis Sjöstedt, 1899 直角头白蚁

Morphology

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

Diagnostic characters

Monotypic genus, containing only Cephalotermes rectangularis (Sjöst.), from Cameroon and Congo. The soldier has a rectangular, flattened-cylindrical head without eyes and 12 antennal segments; the worker mandibles are of a modified Termes type (Hamitermes type) and its antennae have 13 segments; the alate has 14 antennal segments, segment 1 very large and segment 3 small, spiny wings, and no exudate hairs in the female. Holmgren's original description is based on the queen (a dealate) and points out that, judging from the size of its head and thorax, the alate itself should be fairly small.

Alate

The original describes this caste from the queen (Königin). The head is oval and slightly narrowed anteriorly. The frons is flatly convex, slightly depressed in front of the frontal gland pore. The compound eyes are medium-sized and fairly flat; the ocelli are medium-sized and slightly lateral, almost no more than their larger diameter from the compound eyes. The frontal gland pore is small and distinct, situated in the middle of the head. The base of the clypeus is moderately raised and almost as long as half its width, its posterior margin fairly strongly convex and its anterior margin straight and clearly delimited, brighter than the frons. The labrum is wider than long. The mandibular base is small; the mandibles are of Termes type, the basal tooth of the left mandible weakly developed. There are 14 antennal segments, segment 1 very large and segment 3 small. The pronotum is only slightly narrower than the head: head width 0.79 mm, pronotum width 0.7 mm. The posterior margins of the meso- and metanota are emarginate, the posterior projections blunt and rounded. The forewing scale is distinctly longer than the hindwing scale, and the wing surface bears small spines. The female has no exudate hairs; the sides of the queen's abdomen are warty, somewhat wrinkled and weakly pigmented. Because its abdomen is extremely developed, the queen described is unusually large.

Soldier

The head is rectangular and flattened-cylindrical. The frons is slightly inclined. There are no eyes, and the coronal suture is invisible. The frontal gland pore is almost unrecognisable, and the frontal gland is very indistinct and small. The clypeus is lens-shaped; the labrum is quadrangular with rounded anterior corners. The mandibles are short and robust with a large base; the middle part bears 2 small teeth on each side; the base of the left mandible has one small tooth, and the base of the right mandible is mainly rounded. The antennae are slender, with 12 segments, segment 3 shorter and narrower than segment 2 and slightly shorter than segment 4. The pronotum is fairly small and saddle-shaped, with a fairly short anterior lobe. The cerci are small; there are no styli. The fore tibia bears 3 apical spurs, the mid and hind tibiae 2 each.

Worker

Small. The head is oval, fairly thick, flattened and raised; the frontal gland pore is fairly far back. The base of the clypeus is longer than half its width and raised, its posterior margin very strongly arched and clearly delimited, its anterior margin straight. The labrum is small and strongly inclined, wider in the middle than at the base. The mandibles are of a modified Termes type (Hamitermes type). There are 13 antennal segments, segment 3 far shorter and narrower than segment 2 and distinctly shorter than segment 4. The pronotum is short, far narrower than the head and saddle-shaped, the anterior lobe almost as long as the posterior part. The cerci are short; there are no styli. The original adds: the Malpighian tubules have no collecting vesicle, and hindgut segments I–II have no glandular plates.

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.