Caetetermes Fontes

Cuezzo, Carolina, Carrijo, Tiago F. & Cancello, Eliana M., 2015, Caetetermes taquarussu Fontes (Isoptera, Termitidae, Nasutitermitinae): description of the imago caste and new distributional records, Zootaxa 3918 (2), pp. 295-300 : 295-300

Genus Caetetermes Fontes

Caetetermes Fontes, 1981: 135 –137; Krishna et al. 2013: 1544 [catalog]

Type-species. Caetetermes taquarussu Fontes, 1981 , by original designation.

Distribution. Neotropical region ( Brazil, Ecuador, French Guiana, Guyana, Suriname).

Diagnosis. Soldier, head capsule with a strong constriction behind antenna; vestigial mandibles, without point; frontal tube long and cylindrical throughout its length; convex postclypeus, forming a 45° angle with the axis of head capsule in profile; and antenna with 14 articles. Worker, mandibles with concave molar area with ridges and basal notch well-defined; digestive tube with a short mixed segment, dorsal torsion well-developed, first proctodeal segment joining the paunch at the left half of the abdomen in dorsal view.

Caetetermes taquarussu Fontes , Figs 1–16

Caetetermes taquarussu Fontes, 1981: 137 –139 [soldier, figs 1–8; major worker, figs 9–19; minor worker]; Krishna et al. 2013: 1544 [catalog]

Type-locality. ECUADOR. Morona Santiago, Los Tayos Cave Area, 03°06’S 78°12’W.

Description of the imago and additional notes on soldier and worker castes.

Imago ( Figs 1–3 ). Head capsule rounded in dorsal view. In profile, dorsal surface of head capsule shows a slight elevation anterior to fontanelle. Eyes oval, large, and separated from lower margin of head capsule by the same distance as eye to ocelli. Ocelli elliptical in dorsal view, smaller than antennal socket, situated in anterior half of eyes, and removed from them by a length less than the ocelli length. Fontanelle situated in a depression, subequal in length to ocelli and Y-shaped, with short anterior arms. Postclypeus slightly arched in profile, and midline fairly depressed in dorsal view; anterior margin of postclypeus straight, but posterior margin slightly convex; postclypeus width equal to 2.0-2.5x its length. Antennae with 15 articles. Mandibles with apical teeth slightly less developed than first marginal teeth. Left mandible: posterior margin of apical tooth almost straight, forming an acute angle with anterior margin of first marginal tooth (M1+2); straight cutting edge between M1+2 and third marginal tooth (M3); M3 distinct, but smaller than M1+2; M3 separated from molar prominence by a gap; molar tooth barely visible at small gap, and its apex hidden beneath molar prominence; molar prominence concave with developed ridges. Right mandible: second marginal tooth (M2) distinct, but smaller than first marginal tooth (M1); M2 situated at half distance between M1 and molar plate; posterior margin of M2 concave; molar plate concave with developed ridges; basal notch well-defined. Pronotum about equal in width or slightly wider than head without eyes; anterior margin of pronotum elevated, lateral margins concave and converging at rear, and posterior margin not emarginate. Posterior margin of meso- and metanotum deeply emarginate, forming an inverted “V”; posterolateral corners of meso- and metanotum rounded. Tibial spurs 2:2:2. Head capsule with dense coverage of short fine decumbent bristles, and few long scattered erect ones. Labrum covered by short hairs, with two long erect bristles on its midline, and with few shorter bristles at the apex. Pronotum with erect bristles along lateral and posterior margins, and many fine decumbent bristles over its entire surface; these are lighter than the marginal bristles. Wing scales with erect bristles, more abundant over costal margin, and with shorter decumbent bristles over entire surface. Meso- and metanotum with short decumbent bristles. Tergites with dense coverage of short fine decumbent bristles, plus row of erect bristles on each posterior margin. Sternites with erect bristles over entire surface. Head capsule grading from yellow-brown on frons to chestnut-brown posteriorly, or overall dark brown; head capsule with no visible frontal marks. Postclypeus yellow-brown or brown, paler than head capsule. Labrum yellowwhite or yellow-brown, in both cases darker near anteclypeus. Antennal articles yellow-brown or brown. Legs yellowish or yellowish-dark brown. Thoracic nota and tergites yellowish brown or dark brown; sternites lighter-colored than tergites. Figures 1–3 depict darker specimens from Rondônia, MZUSP 12738. Range of measurements (mm) of four females (one from MZUSP 5295, one from MZUSP 12738, and two from USNM 6273): LH, 0.78–0.91; WH, 0.80–0.88; LF, 0.15–0.18; OF, 0.30–0.40; DE, 0.34–0.38; LO, 0.90–0.13; WO, 0.13–0.15; EOD, 0.03–0.04; LP, 0.59–0.63; WP, 0.88–1.05; LMI, 0.97. Range of measurements (mm) of four males, same lots as females: LH, 0.70–0.84; WH, 0.68–0.81; LF, 0.13–0.16; OF, 0.33–0.36; DE, 0.33–0.36; LO, 0.10–0.13; WO, 0.13–0.15; EOD, 0.03–0.04; LP, 0.53–0.67; WP, 0.78–0.97; LMI, 0.97.

Comparisons. Imagoes are known from at least the type-species of the following Neotropical genera of the Nasutitermes group: Caribitermes Roisin, Scheffrahn & Křeček , Constrictotermes Holmgren , Cortaritermes Mathews , Diversitermes Holmgren , Nasutitermes Dudley , Obtusitermes Snyder , Parvitermes Emerson , Rotunditermes Mathews , Tenuirostritermes Holmgren , and Velocitermes Holmgren. The imago of Caetetermes is distinguished from the imagoes of the type-species of these genera by the morphology of the right mandible, which has a distinct right M2 with a concave posterior margin, and a concave molar area with conspicuous ridges. Also, the imago of Caetetermes differs from the imagoes of Rotunditermes by having medium-sized eyes, which are distant from lower margin of head capsule and also from ocelli; from Tenuirostritermes by having small-sized ocelli distant from eyes, which are laterally placed; from Constrictotermes , Diversitermes , Parvitermes , Tenuirostritermes and Velocitermes by having a slightly arched postclypeus, with a faintly convex posterior margin; from Caribitermes , Cortaritermes and Parvitermes by having larger eyes; from Constrictotermes , Cortaritermes , Diversitermes , and Velocitermes by having almost inconspicuous frontal marks; from Caribitermes , Parvitermes and Obtusitermes by having the pronotum with a non-emarginate posterior margin. Caribitermes and Parvitermes have a very sparse pilosity over surface of meso and metanotum, and Obtusitermes have antenna with a ringlike 3rd article.

Soldier ( Figs 4–6 ). Caste described by Fontes (1981, p. 137). Head capsule varying in shape ( Fig. 6 ) with scattered microscopic hairs plus erect bristles. Additional range of measurements (mm) of 83 soldiers from MZUSP 0 294, 5295, 8076, 11713, 12738, 15155, 15157, 19606, 19607, 19608, and USNM 6273: LH, 1.45–1.73; LHp, 0.90–1.05; WHf, 0.53–0.63; WHr, 0.70–0.85; HH, 0.45–0.64; WP, 0.43–0.53; LT, 1.25–1.40. Ratios: LH/WHr, 1.87–2.21; LHp/WHr, 1.10–1.50; LHp/LT, 0.69–0.81.

Worker ( Figs 7–15 ). Two types of workers distinguished by head-capsule pigmentation and mandible morphology. Worker type 1 ( Figs 7, 9 , 11 ) much more frequent than type 2 ( Figs 8, 10 , 12 ). The worker type 2 differs from type 1 by having head capsule brownish yellow, and mandibles with external margin showing a conspicuous concavity before the apical tooth, a larger apical tooth, and left M3 separated from the molar prominence by a wider gap. Coiling gut visible through abdomen. Crop well developed, cuticle ornamented with pectinate scales. Gizzard with a completely sclerotized cuticular armature, columnar folds I and II ornamented with small and sparse spines, pulvillus I well developed with pectinate scales, and pulvillus II reduced ( Figs 13–14 ). Enteric valve armature weakly sclerotized, organized in two distinct rings with tiny spines covering the cushions; posterior ring (closest to P3) with equal six cushions with conical spines ( Fig. 15 ); anterior ring (closest to P1) with three major cushions alternating with three minor ones all having few tiny conical spines. Range of measurements (mm) of nine type 1 workers (three from MZUSP 5295, three from MZUSP 11713, and three from MZUSP 12738): WH, 0.78–0.90; LT, 0.95–1.20; LMI, 0.50–0.60. Ratio: WH/LT, 0.70–0.84. Range of measurements (mm) of six type 2 workers (three from MZUSP 11713 and three from MZUSP 12738): WH, 0.90–0.98; LT, 1.30–1.38; LMI, 0.50–0.60. Ratio: WH/LT, 0.67–0.72.

Material examined. Paratypes. ECUADOR. Morona Santiago, Los Tayos Cave Area, 10.vii.1976, NM Collins coll., LR Fontes det., MZUSP 8076; 27.vii.1976, MZUSP 8078; Santiago Barracks, 03.viii.1976, NM Collins coll., LR Fontes det., MZUSP 8077. Pastaza, Rio Negro, 06.viii.1976, NM Collins coll., LR Fontes det., MZUSP 8079. New records, with imago. BRAZIL. Mato Grosso, Parque Indígena do Xingu, Posto Diauarum, 02.xi-11.xii.1973, RG Kloss coll., MZUSP 0 5295. Rondônia, Porto Velho, UHE Jirau, Abunã, 10.iii.2010, TF Carrijo and RG Santos coll., MZUSP 12738. SURINAME. 19 km from Matapi, 19.v.1982, M. Collins coll., USNM 6273. New records, without imago. BRAZIL. Pará, Castanhal, 28.viii.1965, AF Coimbra Filho coll., MZUSP 294. Rondônia, Porto Velho, UHE Jirau, Nova Mutum Paraná, Caiçara, 30.iii.2012, MM Rocha and RG Santos coll., MZUSP 19607; 10.ix.2012. TF Carrijo and RG Santos coll., MZUSP 19606; UHE Santo Antônio, Jaci-Paraná, Ilha de Búfalos, 12.ix.2010, TF Carrijo and RG Santos coll., MZUSP 15155; Três Praias, Jaci-Paraná, 03.iii.2012, TF Carrijo and J Cabral coll., MZUSP 19608; Nova Mutum Paraná, Jirau, 17.iv.2010, TF Carrijo and RG Santos coll., MZUSP 15156, MZUSP 15157. Tocantins, Aguiarnópolis, 14-19.i.2005, RR Silva and R Silvestre coll., MZUSP 11713.

Distribution ( Fig. 16 ). Brazil (Amazonas; Mato Grosso; Pará, loc. nov.; Rondônia, loc. nov.; Tocantins, loc. nov.), Ecuador, French Guiana, Guyana, Suriname, loc. nov.

Figures

FIGURE 6. Soldiers of C. taquarussu. Variation in the type colony from Ecuador (two on left), in a colony from Rondônia (three in middle), and in a colony from Mato Grosso (two on right).

FIGURE 16. Currently known distribution of Caetetermes taquarussu: circles indicate new records, squares indicate published records, and stars indicate holotype and paratype localities.

FIGURES 1 – 5. Caetetermes taquarussu, MZUSP 12738: 1, female thorax in dorsal view. 2, head in dorsal view. 3, head in profile. 4, soldier head in dorsal view. 5, soldier head in profile. Scale bars: 0.5 mm.

FIGURES 7 – 10. Workers of Caetetermes taquarussu, MZUSP 12738: 7, profile and, 9, dorsal view of worker type 1. 8, profile and, 10, dorsal view of worker type 2. Scale bar: 0.5 mm.

FIGURES 11 – 15. Workers of Caetetermes taquarussu, MZUSP 12738: 11, mandibles type 1. 12, mandibles type 2. 13, gizzard armature type 1. 14, detail of gizzard pulvilli and columns of first and second order. 15, enteric valve cushions. Scale bar for mandibles: 0.2 mm; for gizzard and enteric valve: 40 µ.