Tonsuritermes Cancello & Constantini gen. nov.

Type-species. Tonsuritermes tucki, by present designation.

Diagnosis. Worker and imago. Fontanelle very large in dorsal view, ranging from 1/4 to 3/4 the diameter of the head capsule (Figs. 1B; 2A, C, E); two rows of spine-like bristles on the inner face of the protibia (Fig. 3 A–C).

Description. Imago (Figs. 1; 3A, E–G, I). Head capsule trapezoidal in dorsal view, flattened dorsoventrally in profile (Fig. 1A, B). Two frontal marks located in dorsal view between the postclypeus and ocellus, above the antenna insertion (Fig. 1B, arrows), larger than the ocelli, and two smaller triangular marks between the frontal marks and the fontanelle (Fig. 1B). Fontanelle massive rounded, slightly depressed, occupying 1/2 of the head capsule in dorsal view (Fig. 1B). Eyes rounded, smaller in diameter than the fontanelle. Ocellus small, elliptical, separated from the eye margin by its diameter. Postclypeus moderately inflated, with median line conspicuous (Fig. 1A, B). Labrum with hyaline distal margin. Left mandible (Fig. 3I) with apical tooth much more prominent than M1+2, incision conspicuous, M3 triangular with margins forming acute angle with the tip, point of molar tooth not hidden by molar prominence; molar prominence moderately developed; molar region without ridges. Right mandible (Fig. 3I) with apical tooth much more prominent than M1, M2 triangular with margins forming an obtuse angle with the tip; molar plate moderately developed; molar region without ridges. Pronotum narrower than head without eyes (Fig. 1B, Table 1), anterior margin straight (in Fig. 1B, the image became slightly deformed during the stacking process), lateral margins convex, converging posteriorly. Wings ornamented with asteroid micrasters (Fig. 3 F–G). Profemur subcylindrical. Protibia thin, not inflated (Fig. 3A). Females generally larger than males (Table 1). Pilosity of head capsule with a dense coverage of uniform bristles and short hairs. Labrum with two long bristles and several hairs. Pronotum with bristles and short hairs, mainly along the margins. Tergites and sternites with short bristles and short hairs covering the center of the plates. Procoxa with 4–5 thick bristles. Profemur densely covered by bristles of different lengths (Fig. 3A). Protibia with two rows of 10–12 thick bristles, with the femur, resembling a weakly “raptorial” leg (Fig. 3A). Margin and veins of wings densely covered with hairs (Fig. 3E, F). Coloration of head capsule dark brown, frontal marks and triangular marks slightly lighter than the rest of the head capsule, with poorly defined margins. Fontanelle concolorous with the head capsule (Fig. 1B). Pronotum slightly lighter than the head capsule (Fig. 1B).

Worker. Mono- or dimorphic (Figs. 2; 3 B–D, H, 4, 5). Head capsule flattened dorsoventrally in profile, rounded in dorsal view. Fontanelle margins well delineated, depressed within vertex, occupying 1/4 to 3/4 of the head capsule (Fig. 2A,C, E, see histological discussion below). Antenna with 14 articles. Postclypeus moderately to highly inflated. Left mandible (Fig. 3H) with apical tooth longer than M1+2, cutting edge between M1+2 and incision, incision conspicuous, M3 triangular with lateral sides forming an acute angle with the tip; molar tooth not hidden by molar prominence; molar prominence well developed; molar region concave, without ridges. Right mandible (Fig. 3H) with apical tooth longer than M1; M2 triangular with margins forming an acute angle with the tip; molar plate well developed; molar region concave, without ridges. Pronotum in lateral view (Fig. 2B, D, F) with anterior lobe much longer and forming right angle with posterior lobe. Mesonotum and metanotum subretangular. Thoraco-abdominal glands or dehiscent organs absent. Profemur with ventral surface forming a groove between the two rows of bristles. Protibia with ventral face strongly flattened, resembling an interlocking raptorial leg (Fig. 3B, C). Digestive tube (Fig. 4) with inner mixed segment vestigial (Fig. 4C); P1 with uniform diameter throughout, forming an inverted 'C' in ventral view; P2 not armed, composed of six symmetrical cushions covered with faint polygonal scales (Fig. 4 E–F) and 3–5 small short triangular spines in the proximal region of the cushions (Fig. 4F). Enteric valve seating tubular, without lobes. Paunch with P3a pyriform and P3b forming an Sshaped, isthmus conspicuous in almost all the specimens; P4 of uniform width, passing under mesenteron in the sagital line and making a 180° loop in the left side of body right before the P5. Pilosity of head capsule covered by bristles of variable orientation and length. Pronotum with long bristles with variable orientation, in greater number on margin of the anterior lobe and in the rounded regions in the posterior lobe. Tergites and sternites with short bristles in the center of the plates, in variable orientations. Procoxa with 7–11 thick bristles. Profemur with two rows of bristles less striking and organized than the protibia (Fig. 3B, C). Protibia with two well marked rows of spine-like bristles (thick and short) on inner margin; number of spine-like bristles varying from six to 16 (Fig. 3B, C). Head capsule coloration whitish yellow; fontanelle lighter (Fig. 2A, C, E, 3D).

Comparisons. Tonsuritermes, with its massive worker and imago fontanelle, differs from all known New World Apicotermitinae. Tonsuritermes is close to Aparatermes Fontes, 1986 (worker width of head of A. abbreviatus = 1.16 mm (mean), Fontes 1986) and Ruptitermes Mathews, 1977 in size (worker width of head of R. reconditus (Silvestri, 1901) = 1.13 mm (mean), Acioli & Constantino 2015). In Snyder's (1926) description for Anoplotermes grandifons, he highlights the fontanelle as a diagnostic feature of the species with a description based only on a wingless female: 'Fontanelle a very prominent hyaline oblong depression, slightly on a bias, 0.25 mm in length and 0.20 mm in width’. The fontanelle of the imago of Tonsuritermes tucki is not hyaline and has the maximum diameter between 0.34–0.36 mm. Snyder does not make any mention of bristles or spine-like bristles in the legs. Efforts were made to examine the type material of A. grandifons, but without success. Thus, for the difficulty of comparisons using only the description of the imagoes we considered our samples different from A. grandifons . The protibia and profemur with thick spines, although also a very distinct characteristic in relation to the other described termites in the subfamily, has been observed in other groups of termites not related to the genus and not yet described (JC, unpublished data).

Histological discussion. The large region of frons in Tonsuritermes tucki workers is formed by a frontal gland of unique structure, even compared to other members of the Anoplotermes -group studied previously (Šobotník et al. 2010a) (see Fig. 5 A–C). This observation was corroborated by transmission electron microscopy that revealed the glandular nature of the tissue. The most unusual feature is the cuticle overlying the frontal gland, which is made of two discrete layers of modified cuticle, both being very different from normal head cuticle (see Fig. 5B). The two-layered glandular cuticle is a unique character not shared by any other termite gland studied so far, just slightly reminding the two cuticles occurring in presoldiers of Prorhinotermes simplex (Hagen, 1858) (Šobotník et al. 2004) . The glandular cells were severely damaged by the 80% alcohol, and the specialised secretory organelles (e.g. microvilli, endoplasmic reticulum or Golgi apparatus) could not be observed. We also cannot confirm the existence of the second cell layer and the envelope cells observed in Aparatermes (Šobotník et al. 2010a) . However, locally the cell remanent contained electron-lucent secretory vesicles and abundant mitochondria. We hope to acquire the living material in the future, allowing us to describe the ultrastructure of this peculiar secretory organ in detail.

Etymology. From Latin tonsura (“a clipping, trimming”). “Tonsure” is named after Franciscan monks’ haircut, which the fontanelle resembles, particularly in the workers. The idea for the name came from a note written by Filippo Silvestri (MZUSP 1199, 03.i.1909) for a sample of this genus he examined where he indicated a possible name for the species: "magnotonsura".

Distribution. Neotropical region: Brazil, Colombia, French Guiana, Paraguay, Peru (Fig. 6).

Tonsuritermes tucki Cancello & Constantini sp. nov.

(Figs.1; 2 A–D, 3A–B, D–I, 4, 5, 6)

Holotype. Worker type 1 from lot MZUSP 6480 (in a separate vial with the remaining sample).

Type-locality. BRAZIL. Santa Catarina: Campos Novos, lat 27.40S , long 51.22W.

Type-repository. MZUSP

Paratypes. BRASIL. Bahia: Andaraí, lat 12.8072S, long 41.3313W, 13–14.xii.1990, EM Cancello & MT Ponte coll., MZUSP 10367; Goiás: Caldas Novas, Parque Estadual da Serra de Caldas Novas, lat 17.7927S, long 48.7038W, 23.iii.2008, DE Oliveira coll., UFG 1740, 1741 ; Minas Gerais: Poços de Caldas, Morro do Ferro (Norte), lat 21.9166S, long 46.5166W, 18.ix. 1967, RL Araujo coll., MZUSP 0456 ; Mato Grosso do Sul: Aquidauana, lat 20.4711S, long 55.7872W, 29.v.2012, AR Abot coll., MZUSP 27373 ; Rio de Janeiro: Santa Maria Madalena, Parque Estadual do Desengano, lat 21.9522S, long 42.0148W, 24.xi.2016, JP Constantini coll., MZUSP 26687; Rondônia: Porto Velho, Abunã, lat 9.5970S, long 65.3645W, 09.iii.2010, TF Carrijo & RG Santos coll., MZUSP 13039; Jaci Paraná, lat 9.0245S, long 64.2530W, 16.ix.2010, TF Carrijo & RG Santos coll., MZUSP 17193; lat 9.4502S, long 64.3674W, 12.i.2011, RG Santos & CY Mandai coll., MZUSP 17196; lat 9.0293S, long 64.2499W, 07.i.2011, RG Santos & CY Mandai coll., MZUSP 17197; lat 9.4526S, long 64.3900W, 20.i.2010, TF Carrijo & RG Santos coll., MZUSP 17198; Nova Mutum Paraná, lat 9.2869S, long 64.7445W, 09.i.2011, RG Santos & CY Mandai coll., MZUSP 17194, 17195; (same holotype sample), 23.xii.1975, RL Araujo coll., MZUSP 6480, (imago, workers); São Paulo: São Paulo, lat 23.53S, long 46.62W, 3.i.1909, Luederwaldt coll., MZUSP 1199 . COLOMBIA. Meta: San Juan de Arama, lat 3.34639N, long 73.8894W, vii.1992, LO Sánchez coll., MZUSP 24480 . FRENCH GUIANA. Régina: Nouragues Nature Reserve, lat 4.0833S, long 52.6833W, T Bourguignon coll. ; PARAGUAY. Cordillera: Vallenzuela, lat 25.5833, long 56.8667W, 04.i.1992, L Cabello & B Barrios coll., MZUSP 10855 . PERU. Madre de Dios: Tambopata, Research Lodge, lat 13.13700S, long 69.61200W, 09.ix.2015, L Carnohan, UF PU1104 .

Diagnosis. Dimorphic worker with fontanelle of two sizes; head capsule with two lengths of well marked bristles and bristles on tergites uniformly oriented backwards.

Imago. As described for the genus.

Worker. Dimorphic (Fig. 2 A–D). Head capsule with two lengths of well marked bristles. Bristles on tergites uniformly oriented backwards. Postclypeus moderately inflated. Protibia inflated. Worker (type 1, W1) with fontanelle occupying 3/4 of the cephalic capsule in dorsal view. Worker 2 (type 2, W2) with fontanelle occupying 1/4 to 1/2 of the cephalic capsule in dorsal view.

Etymology. In reference to the character Friar Tuck, the supposed Franciscan monk of the legend of Robin Hood.

Biological notes. Collected foraging in galleries in the ground, at base of trees, among litter and sticks and under rotting log.

Comments. We described as two types of workers because there are two sizes of fontanelle. To know if it is the same worker with the fontanelle changing over time, it would be necessary to do a developmental analysis, and this is out of the scope of the present paper. For taxonomic purposes, it is important to know that two types of workers can be found in the same sample.