Labiotermes emersoni (Araujo) Araujo, 2006

Constantino, Reginaldo, Acioli, Agno N. S., Schmidt, Karen, Cuezzo, Carolina, Carvalho, Sérgio H. C. & Vasconcellos, Alexandre, 2006, A taxonomic revision of the Neotropical termite genera Labiotermes Holmgren and Paracornitermes Emerson (Isoptera: Termitidae: Nasutitermitinae), Zootaxa 1340, pp. 1-44 : 11-14

Labiotermes emersoni (Araujo) , new combination

Paracornitermes emersoni Araujo, 1954: 183 [soldier]; Fontes 1998: 374 [gut, figs. 17–20]

Holotype: soldier ( MZSP), examined.

Type­locality: Brazil: São Paulo.

Imago ( Figs. 2 H–K, 12B). Head capsule rounded; fontanelle conspicuous, elliptical, about the same size as antennal socket. Eyes oval, moderately large, separated from the lower margin of head capsule by about 1/5 of its diameter; ocelli small, elliptical, smaller than antennal socket. Postclypeus moderately arched in profile. Pronotum about the same width as head without eyes. Mesonotum and metanotum with deeply emarginate hind margins. Left mandible: distance from M3 to M4 about the same as distance fromM1 to M3; distance from A to M1 shorter than the distance from M1 to M3; M3 conspicuously smaller than M1. Right mandible: distance from A to M1 about the same as distance from M1 to M2; M2 small. Antenna with 16 articles. Head capsule light brown; postclypeus brownish yellow; fontanelle yellow; pronotum and tergites lighter than head capsule; sternites brownish yellow; wings transparent, brownish. Head capsule and postclypeus with sparse, straight and long bristles; pronotum with numerous straight, shorter bristles near margins and a few longer bristles on surface; tergites and sternites densely covered with bristles and hairs of variable size; wings densely covered with minute hairs. Measurements in Table 1 .

Comparisons. The imago of L. emersoni can be recognized by the comparatively small apical tooth on both mandibles, and their straight posterior edge. All other known species have larger eyes and ocelli and smaller fontanelle and most, except L. brevilabius , have antenna with 17 articles or more. The head of L. leptothrix is densely covered with very short hairs.

Soldier ( Figs. 2 A–G, 11B). Head capsule subrectangular, with parallel sides in dorsal view; sides slightly convex. Frontal tube very short, upturned; fontanelle posterior to line of antennal sockets. Top of head in profile almost straight. Antenna with 15 articles. Labrum longer than broad; sides convex. Mandibles short, robust and curved. Left mandible: cutting edge between apical and 1st marginal S­shaped; cutting edge between marginal teeth concave. Right mandible with two marginal teeth, about the same size and grouped together near base. Front coxa with a lateral conical projection near base. Head capsule and labrum brownish yellow; thorax and legs lighter than head capsule; tergites and sternites yellowish. Head capsule with numerous short and straight bristles of unequal size; postmentum with a few bristles on anterior margin; pronotum with a row of numerous bristles on anterior margin and few bristles on posterior margin; tergites and sternites densely covered with bristles and fine hairs. Measurements in Table 2 .

Comparisons. The soldier of L. emersoni can be recognized by the shape of the mandibles and the frontal tube. The most similar species is L. laticephalus , which is larger (on average, but there is some overlap), more hairy and has a more conspicuous frontal tube with narrow tip.

Worker ( Figs. 2 L– O, 13B, 15C–D, 16B). Head capsule and postclypeus with numerous straight bristles. Pronotum with numerous bristles on anterior lobe and a few bristles on posterior margin. Mesonotum with 4 bristles on posterior margin, distant from the middle. Front coxa with a lateral conical projection near base. Antenna with 15 articles. Fontanelle rounded. Enteric valve typically with 4 finger­like ridges of different sizes covered with fine spines. Rarely with 5–6 ridges. Mixed segment with two mesenteric lobes; large lobe elongate, proximal part narrow; small lobe oval, much smaller, its proximal part very narrow. Measurements in Table 3 .

Comparisons. The worker of L. emersoni is very similar and difficult to differentiate from L. laticephalus . The mandibles and enteric valve are almost identical considering the observed intra­specific variation. L. laticephalus is larger on average, but there is some overlap. The only consistent difference observed is the greater number of hairs on the head and thorax of L. laticephalus .

Geographical distribution. L. emersoni occurs in Brazil (Cerrado and Caatinga) and in the Chaco of northern Argentina and Paraguay ( Fig. 18 ). It probably occurs also in southern Bolivia. It has been reported from the following habitats: cerrado vegetation, dry forest, pasture, and urban areas. Soldiers from the western part of its geographic range tend to be smaller.

Material examined

ARGENTINA. Chaco. Parque Nacional Chaco: s., w., 13.xii.2000, C. Szumick & F. Cuezzo (IFML­109); s., w., 13.xii.2000, C. Szumick & F. Cuezzo (IFML­110). Santiago del Estero. Copo, Parque Nacional Copo: w., 24.x.2003, F. Cuezzo et al. (IFML­151). Copo, Ruta Nacional 16: s., w., 16.xii.2000, C. Szumick & F. Cuezzo (IFML­111). BRAZIL. Ceará. Aiuaba: s., w., 29.x.2004, A. Vasconcellos ( DSEC). Crato: s., w., 18.x.2004, A. Vasconcellos ( DSEC). Distrito Federal. Fazenda Água Limpa: s., w., 26.viii.1986, R. Constantino (MPEG­2617). Jardim Botânico de Brasília: s., w., 26.viii.1986, R. Constantino (UnB­3537). Goiás. São Domingos, Monte Alto: s., w., 01­ 07.ix.2003, D.L. Bernardo (UnB­4255, 4269, 4270, 4312, 4366, 4380, 4422). Mato Grosso. Alto Garças: s., w., 08.vii.1965, Goodland (MZSP­10827). Chapada dos Guimarães, Rio Manso: s., w., 14.i.1999, R. Constantino (UnB­0818). Minas Gerais. Bocaiúva: s., w., 25.vii.1975, R.L. Araujo (MZSP­5934). Curvelo: s., w., 03.x.1956, R.L. Araujo (MZSP­4459, 4460). Diamantina: s., w., im., 23.viii.1971, R.L. Araujo (MZSP­ 4942). Morro da Garça: s., w., im., 20.x.1964, Exp. Dep. Zool. (MZSP­2016). Poços de Caldas: s., w., im., 04­13.ix.1967, R.L. Araujo (MZSP­504, 505, 507, 508, 509, 512, 513). Rio Pardo de Minas: s., w., 10.i.1952, R.L. Araujo (MZSP­4308). Sete Lagoas: s., w., 28.iii.1985, D.J. Domingos (UnB­2298). Paraíba. Sumé, Fazenda Almas: s., w., 07.iii.2003, A. Vasconcellos ( DSEC). Rondonia. Pimenta Bueno: s., w., 21.vii.2000, R. Constantino (UnB­2421); s., w., 21­24.vii.2000, R. Constantino (UnB­2423, 2518). São Paulo. São Paulo: s., w., im., 25.x.1907, H. Luederwaldt (MZSP­216). Tocantins. Dianópolis, Fazenda Novo Iguaçu: s., w., 22.ix.2003, D.L. Bernardo (UnB­5027). Paraná, Fazenda São João: s., w., 12­18.ix.2003, D.L. Bernardo (UnB­4879, 4961, 4970, 4978, 4987); s., w., 27­28.iii.2004, G.C. Costa (UnB­5412, 5429, 5458).

Figures

FIGURES 2. Labiotermes emersoni. Soldier from Minas Gerais: A, head in dorsal view; B, pronotum in dorsal view; C, head in profile; D, pronotum in posterior view; E, right front leg; F, postmentum. Soldier from Rondonia: G, head in profile. Imago: H, head in dorsal view; I, pronotum; J, head in profile; K, antenna. Worker: L, head in dorsal view; M, thorax; N, head in profile; O, right front leg. Scale bars = 1.0 mm.

FIGURES 18. Geographic distribution of Labiotermes emersoni. The double circle indicates the type­locality.