Genus Dihoplotermes · 双戟白蚁属

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

Soldier mandible base and the region above the condyle each bear 1 anterior marginal spine on either side; mandibles asymmetrical, of the snapping type; labrum asymmetrical; tibial spur formula 3:2:2. Worker mandible apical tooth distinctly larger than the first marginal tooth; right mandible without a second marginal tooth; left mandible without a third marginal tooth, the molar tooth separated from the first and second marginal teeth by a small notch. The gut of worker and soldier shares the following features: the columnar band of the gizzard bears 6 primary and secondary folds, the first-order pad (pulvillus) has 1 short spine at its centre; the Malpighian tubule node bears 2 pairs of Malpighian tubules; the enteric valve has 6 pads, 1 of which has a row of longitudinal spines at its distal end.

Soldier

Head capsule yellow, subrectangular, almost the entire surface irregularly scattered with setae of varying length; setae dense at the apex of the frontal projection. Anterior side of the head capsule, near the mandible base, with 1 spine on either side. Anterior part of the head with a prominent projection which, in dorsal view, covers part of the labrum and nearly reaches the lateral margins of the head; the anteroventral margin of the projection is concave above the mandibles and forms a small step in profile, and its margin directly above the antennal sockets bears 2 small projections. Postmentum narrower at the middle, the anterior part slightly wider than the posterior, the posterior margin with 1 spine-like projection visible in profile. Mandibles asymmetrical, dark: proximal 2/3 of the left mandible slightly curved inwards, the distal part slightly wider but narrowing towards the apex, curving sickle-like to the right to form a small notch that receives the right mandible; outer margin of the right mandible nearly straight, narrowing towards the apex, also with a notch that receives the left mandible when closed; apex pointed, slightly curved to the left. Labrum symmetrical, with 7–8 long setae usually arranged in 2 rows, apex slightly curved, anterior margin pointed. Antennae 14-segmented; scape about 3 times as long as segment 2, segments 3–4 equal in length and shorter than segment 5, segments 6–8 equal in length, the remaining segments subequal. Margins of the pronotum, mesonotum and metanotum with long, sparse setae; anterior part of the pronotum with microtrichia. Tergites and sternites of the abdomen covered with long setae. Surface of the fore tibia irregularly scattered with a few long setae. Tibial spur formula 3:2:2; apex of the mid tibia with another spine beside the spur, easily mistaken for the third spur; this tibial spine is present in all castes.

Worker

Head capsule white, uniformly scattered with setae of varying size except on the anterior margin; fontanelle slightly distinct. Postclypeus slightly inflated, with a few setae; setal density of the labrum similar to that of the clypeus. Antennae 14-segmented, scape longer than segment 2, subsequent segments gradually lengthening. Apical tooth of the left mandible larger than and slightly longer than the first and second marginal teeth combined; inner margin of the apical tooth slightly concave, a small notch between the first and second marginal teeth and the molar tooth; molar prominence distinct, without striae. Apical tooth of the right mandible well developed, longer than the first marginal tooth; second marginal tooth indistinct; molar plate slightly concave, without striae. Anterior part of the pronotum with microtrichia, anterior margins of the pronotum, mesonotum and metanotum with long setae. Abdomen transparent, tergites and sternites densely covered with short setae, posterior part of each sternite with 1 row of long setae. Fore tibia slightly broadened, surface densely covered with setae of varying size. Gut: gizzard small, columnar band with 6 first- and second-order folds, first-order pad with a short spine at its centre; Malpighian tubule node situated on the mesenteric tongue, 2 pairs of Malpighian tubules attached at the same point; enteric valve with 6 pads of varying shape and size, 5 of them with a few short spines at the distal end and 1 with a row of longitudinal spines at the distal end; colon distinctly wider than the midgut.

Alate

Head capsule brown, densely covered with short setae mixed with a few long setae; fontanelle distinct, drop-shaped, forming a small depression on the vertex; ocelli small, semicircular, protruding; compound eyes medium-sized, round, protruding. Postclypeus small, yellowish brown, sub-trapezoidal, slightly inflated, surface densely covered with setae of varying size; labrum with many setae, at its widest about as wide as the postclypeus. Apical antennal segment broken off; scape relatively broad, about 3 times as long as segment 2, segment 3 equal in length to segments 4–7, subsequent segments gradually lengthening. Pronotum light brown, covered with setae except at the middle and near the margin below the anterior lobe; slightly narrower than the head; anterior part with microtrichia, median carina weak but visible on the anterior margin. Anterior part of the mesonotum and metanotum dark yellow, posterior part dark brown, the anterior part narrowing posteriorly to the tips of the wing buds and partly covered by them; posterior margin bilobed, the posterior margin of the mesonotum semicircular and of the metanotum V-shaped. Abdominal tergites concolorous with the pronotum, with numerous small setae and a few long setae; sternites light brown at the sides, dark yellow near the midline, posterior margin of each segment with 1 row of long setae. Anterior proximal surface of the fore coxa with small projections; tibia slender.

Sources: Azevedo R. A. de; Dambros C. de S.; Morais J. W. de 2019. A new termite species of the genus Dihoplotermes Araújo (Blattaria, Isoptera, Termitidae) from the Brazilian Amazonian rainforest. Acta Amazonica 49(1): 17–23., pp. 18–21 This text is an adaptation, not a verbatim transcription of the original.