Hyleotermes brevipilus Emerson, 1925 短毛森林白蚁

Morphology

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

Diagnostic characters

Soldier head capsule oval in dorsal view, with a long cylindrical nasus, without a constriction and without long setae, covered with microscopic hairs; worker slightly dimorphic, the mixed segment very short; enteric valve with 6 pads of unequal size, each bearing from a few to several dozen narrow spines set on conical bases. In its small size, pale yellow colour and cylindrical nasus the soldier is closest to Ereymatermes and Subulitermes; of the three, only H. brevipilus, S. constricticeps and S. microsoma lack long setae on the head capsule, and the latter two are distinctly smaller (head width about 0.6 mm). The worker enteric valve is diagnostic and differs from Ereymatermes and Subulitermes. It differs from Nasutitermes s. str. as follows: the latter has an enteric valve armature with acute scales drawn backwards into scale rows, a narrow straight molar plate with well-developed ridges, short apical teeth and larger marginal teeth on the inner mandibles, a very long mixed segment, and an unclerotised enteric valve with only spinules; moreover, female workers of Nasutitermes s. str. are distinctly larger than males.

Alate

Compound eye large, somewhat oval; ocellus large, elliptical, about as large as the antennal socket; postclypeus slightly arched in profile, the midline distinct and slightly concave, the anterior margin nearly straight, the posterior margin convex; fontanelle distinct, slit-like; frontal suture faint; antennal segments 15; inner mandibular tooth pattern similar to that of worker morph 2; pronotum trapezoidal in dorsal view, the anterior and posterior margins nearly straight; the posterior margins of the meso- and metanotum deeply and broadly concave, the posterolateral corners rounded; spur formula 2:2:2.

Soldier

Monotypic; head capsule longer than wide in dorsal view, without a constriction; nasus slender, almost cylindrical; head capsule, legs and thoracic sclerites densely covered with short, rather coarse setae; inner mandibles with a small but distinct 'point'; antennal segments 12; postclypeus not convex in profile; labrum wider than long, the anterior margin rounded, the sides parallel, the anterolateral corners rounded; anterior and posterior pronotal lobes equally developed, forming an obtuse angle between them; fore coxa conical, not forming a ridge, without a boss on the anterior surface; spur formula 2:2:2.

Worker

Dimorphic, the two morphs similar in size. In morph 1 the gap between M3 and the molar prominence of the left inner mandible is narrow, the head capsule darker and nearly trapezoidal, and the pronotum narrower with the anterior lobe larger than the posterior; in morph 2 the gap is wide, the head capsule slightly paler with more convex sides, and the pronotum broader with the anterior and posterior lobes nearly equal. In both morphs the fontanelle lies in the posterior half of the head capsule, is pale and slightly concave in profile; postclypeus not inflated; antennal segments 13; spur formula 2:2:2. In both morphs the apical tooth of the left inner mandible is larger than M1, the posterior margin of the apical tooth slightly concave, the posterior margin of the apical tooth forming an acute angle with the anterior margin of M1, and the posterior margin of M1 undulate; M3 short but distinct, with a V-shaped gap to the molar prominence in morph 1 and a wide gap in morph 2; M4 short, hidden beneath the molar prominence; molar prominence concave with faint ridges. Right inner mandible: apical tooth larger than M1, M3 reduced with a rounded end, the posterior margin of M3 concave, the molar plate concave with faint ridges, the basal notch distinct but narrower in morph 2.

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.