Genus Engelitermes · 恩格尔白蚁属

Morphology

The descriptions below are an adaptation of the original genus-level accounts; terms follow the meaning of the source, and the original is not transcribed verbatim.

Diagnostic characters

In overall morphology the soldier most closely resembles the African Cephalotermes and the Neotropical Cylindrotermes, but its gut contains no solid food particles (termed white-gutted in the original), which distinguishes it from both; its soldier is consistently smaller than the mandibulate soldiers of African Termitinae, its size comparable to that of Forficulitermes planifrons (maximum head width 0.63 mm versus 0.65 mm), but the mandible shape is entirely different. The worker mandibles are of the soil/humus-feeding type, whereas those of Cephalotermes and Cylindrotermes workers are wood-feeding: apical tooth broad and widely separated from the first marginal tooth, molar region concave and without ridges (similar to Crenetermes, Eutermellus, Jugositermes and Thoracotermes); it is especially similar to the worker of Forficulitermes in the wide gap between the apical tooth and the first marginal tooth and in the well-developed first and fourth hindgut segments. The combination of 'a single spine plus unornamented pad cuticle' in the enteric valve is unique among termite enteric valves; the gizzard structure is simplified compared with most Termitinae.

Alate

Described from a single physogastric queen only: head brown, bearing several hundred setae of varying length, mostly directed forwards, arising from translucent setal sockets; the median branch of the frontal suture darker than the rest of the head; fontanelle small, circular, situated between the two ocelli; anterolateral part of the head with two crescent-shaped markings anterior to the fontanelle. Pronotum and postclypeus paler than the vertex, with a similar pilosity; postclypeus not inflated. The antennae of the specimen examined are broken but comprise more than 10 segments; segments 3 and 4 almost fused, segment 3 shorter than segment 2, segments 3 and 4 together longer than segment 2. Apical tooth of the mandibles narrower than in the worker. Tibial spur formula 2:2:2.

Soldier

Head capsule nearly rectangular in dorsal view, the lateral margins slightly convergent posteriorly; frontal surface raised near the fontanelle and undulating in lateral view; fontanelle small, almost indiscernible; mandibles stout, with 1 triangular tooth at the base; antennae 12-segmented; anterior and posterior lobes of the pronotum congruent, together forming a straight-sided triangle in lateral view; tibial spur formula 2:2:2; abdomen yellowish white, the gut without solid food residues (white-gutted sensu Scheffrahn et al. 2017).

Worker

In dorsal view a large white brain (supraoesophageal ganglion) is visible within the head capsule, anterior to the small diamond-shaped frontal gland; postclypeus slightly inflated in lateral view. Apical tooth of the mandibles broad and prominent; the gap between the apical tooth and the first marginal tooth of the left mandible greater than the distance between the first and the third marginal teeth; molar region concave, without ridges. Antennae 12-segmented; tibial spur formula 2:2:2; fore femur slightly inflated. Gizzard lacking a columnar belt, the pulvillar belt with sclerotised spines, beneath which lie patches of ridge-like scales. Enteric valve composed of 6 smooth, slender pads, each with 1 small spine at its distal end, the pads directed towards the food stream; the enteric valve armature (EVA) has 1 slightly sclerotised pad anterior to the ring, bearing 1–2 stout spines and several small spines. Mixed segment absent. Ileum cylindrical, running along the left side of the abdomen in a long S-shape, narrowing posteriorly and folding forwards to meet P2; P4 broad anteriorly and narrow posteriorly; P5 unusually large in volume (but not in all individuals).

Sources: Romero Arias J., Hellemans S., Kaymak E., Akama P.D., Bourguignon T., Roisin Y., Scheffrahn R.H. & Šobotník J. 2024. Mitochondrial phylogenetics position a new Afrotropical termite species into its own subfamily, the Engelitermitinae (Blattodea: Termitidae). Systematic Entomology 49: 72–83. https://doi.org/10.1111/syen.12607, pp. 78–79（Engelitermes gen. n.: Description / Diagnosis） This text is an adaptation, not a verbatim transcription of the original.