Angularitermes coninasus Carrijo & Rocha

Carrijo, Tiago F., Rocha, Mauricio M., Cuezzo, Carolina & Cancello, Eliana M., 2011, Key to the soldiers of Angularitermes Emerson with a new species from Brazilian Amazonia (Isoptera: Termitidae: Nasutitermitinae), Zootaxa 2967, pp. 61-68 : 64-67

Angularitermes coninasus Carrijo & Rocha , new species

Holotype. Soldier, part of lot MZUSP 13445, Brasil, Rondônia, Porto Velho, Jaci-Paraná, Ilha da Pedra module from the Fauna Monitoring Program of Santo Antônio UHE, transect two, 3850 meters, 0 9o 09’S 64o35’W; T. F. Carrijo & R. G. Santos coll.; 14.ix.2010.

Paratypes. The remain specimens from holotype’s sample (workes and soldies) and Brazil, Amazonas, Humaitá, 13.ix.1990, R. Constantino coll. ( MZUSP 9425), part of the sample from the Museu Paraense Emílio Goeldi, ( MPEG 3680).

Etymology. The specific epithet coninasus is a combination of the Latin term conus (meaning cone) and frontal tube as a reference to the conical shape of the soldier frontal tube.

Description. Imago. Unknown.

Soldier ( Figs. 2 A and 3). Monomorphic. Head capsule pyriform in dorsal view. frontal tube conical, with a slight to strong constriction at the base ( Fig. 3 A), pointing upward in profile. Postclypeus well-developed; projected upward and forward ( Fig. 3 B). Mandibular blade reduced to conspicuous “points”. Labrum shorter than wider; anterior margin of labrum rounded. Antennae with 14 articles; 1st article is the largest with at least twice the length of 2nd; 3rd longer than 2nd; from 4th to 7th or 8th slightly longer than the anterior; from the 8th to the last, one shorter than the next, the last is as long as the 2nd. Anterior lobe of pronotum trapezoidal, almost rectangular, with anterior margin slightly emarginated. Legs very long; tibiae longer than head capsule length. Frontal tube with a microsculpturing of irregular pits concentrated at the first half, some pits may reach near the apex. Surface of the head capsule covered by thick bristles and hairs. Frontal tube surface with a few sparse bristles and a dense layer of decumbent short hairs; frontal tube apex with four rigid bristles smaller than those of head. Labrum glabrous. Bristles of the antennae concentrated at the apex of each article with short hairs on their surface; first article with bristles restricted to the apex. Pronotum with bristles on margins and two or three over its surface. Meso- and metanotum with many thick bristles on lateral and posterior margins. Abdominal tergites covered by many thick bristles of different sizes. Abdominal sternites with a line of thick, erected bristles and sparse short hairs oriented backward. Legs with many thick bristles and hairs over their surfaces. Tibial spurs 2:2:2. Head capsule varying from ferruginous orange to pale yellow, frontal tube brown/red, always darker than the head capsule. Body yellow to pale yellow. Measurements of four soldiers from MZUSP 9425 and four from MZUSP 13445: LN (1.38–1.44), LH (1.32–1.38), WN (0.61–0.67), WH (1.17–1.25), LT (2.27–2.40), LN/WH (1.11–1.18), LN/ LH (1.00–1.05), LH/LT (0.57–0.60).

Worker ( Figs. 4–8 ). Dimorphic. Differences among the dimorphic workers are restricted to their size. Head capsule trapezoidal, fontanelle and epicranial suture inconspicuous. Antennae with 15 articles, if 14 the 3rd is always subdivided. Postclypeus inflated. Anterior lobe of pronotum slightly emarginated. Tibial spurs 2:2:2. Head capsule with many bristles. Pronotum with bristles on the anterior and posterior margins; meso- and metanotum with bristles on posterior margins; abdominal tergites covered with many bristles and hairs; sternites with bristles and a dense layer of short hairs. Legs covered by scattered bristles and hairs. Measurements of four major and four minor workers from MZUSP 9425 and MZUSP 13445 are given as a range: major, WH (1.32–1.36), LT (1.87– 1.96); and minor, WH (1.17–1.19), LT (1.64–1.74).

Mandibles ( Fig. 4 ). Left mandible: apical tooth slightly larger than M1+2; angle between apical tooth and M1+2 tooth nearly acute; M3 with half size of M1+2; notable gap between M3 and molar prominence; molar tooth apex hidden by molar prominence; molar prominence very concave and without ridges. Right mandible: apical tooth approximately twice the size of M1; M2 reduced or absent; molar plate very concave and without ridges.

Digestive tube ( Figs. 5–8 ). Crop well developed. Gizzard armature complete, surface of folds I and II ornamented with small and sparse spines ( Fig. 7 A); pulvillus I well developed, covered with long aciculiform spines on the superior portion and many lines with very small spines (4–6) on the inferior portion ( Fig. 7 B), pulvillus II reduced, surface smooth. Anterior end of midgut with a distinct hump dorsal to the insertion of the gizzard. Mixed segment very short, mesenteric tongue external to mesenteric arch ( Fig. 6 A). Malpighian tubules attached individually but closely adjacent in pairs at mesenteron-proctodeum junction; each tubule conspicuously dilated in its proximal part ( Fig. 6 A and B). Proctodeal segment (P1) short and tubular throughout its length. Enteric valve (P2) visible at left side ( Fig. 5 B). P2 with three major cushions intercalated with three minor ones ( Fig. 8 ): major cushions with shorter spines on its surface and, after a deflection on the distal portion, a row of 4–6 larger spines pointing inward to gut lumen ( Fig. 8 , large arrows); minor cushions with only sparse small spines ( Fig. 8 , thinner arrows). Paunch (P3) with P3a and P3b dilated; proximal part of colon (P4a) dilated; U-turn short and visible at right view.

Biology. All samples were collected in a primary rainforest. A. coninasus n. sp. type material was sorted out of a domed shaped epigeal nest, measuring 29 cm in height and 55 cm in width at its base ( Fig. 9 ). The surface of the nest was covered by loose soil, which also formed the peripherical layer of about 5 cm in depth with noticeable galleries larger than 1 cm in diameter. Galleries at the internal layer had 0.5 cm diameter and were occupied by intertwined roots extending almost 10 cm down in soil. There were no chimneys communicating interior with exterior. The nest was surrounded by a shallow litter layer and some sticks. Neither inquilines nor real pair were found within A. coninasus n. sp. nest.

Comparisons. Soldiers of Angularitermes coninasus n. sp., can be easily recognized among its congeners by having a short and strongly conical frontal tube, with a wide base. The combination of characters as microsculpture of the head capsule and frontal tube, pilosity and coloration distinguish A. coninasus n. sp. from the other species. A. tiguassu is morphologically similar to the new species but has a much narrower frontal tube at the base; antennae with 15 articles and LH/LT index 0.66–0.68. Workers are dimorphic. No other species of Angularitermes was reported as nest-building.

Figures

FIGURE 2. Angularitermes soldier head, in profile: A, A. coninasus n. sp. (paratype); B, A. nasutissimus; C, A. orestes (paratype); D, A. tiguassu (holotype); E, A. pinocchio (paratype); and F, A. clypeatus (holotype).

FIGURES 3. Angularitermes coninasus n. sp.: 3 A, soldier head capsule, dorsal view. 3 B, postclypeus, frontal view.

FIGURE 7. Angularitermes coninasus n. sp.: A, gizzard; and B, detail of the pulvillus I. f 1, f 2 and f 3: first, second and third order folds, respectively, p 1 and p 2: pulvillus I and II respectively; and arrow: spines on the folds.

FIGURE 8. Enteric valve armature of the worker of Angularitermes coninasus n. sp., showing major cushions (large arrows) intercalated by minor cushions (thinner arrows). Observation: when enteric valve was mounted major cushions adopted different positions but there are no differences between them.

FIGURE 9. Nest of Angularitermes coninasus n. sp. from Rondônia, Brazil.

FIGURES 4 – 6. Worker of Angularitermes coninasus n. sp.: 4, mandibles; 5, digestive tube in situ: A, dorsal; B, right; C, ventral; and D, left views; 6, detail of mesenteric tongue and Malpighian tubules: A, profile; and B, internal views.