Rugitermes tinto: A new termite (Isoptera, Kalotermitidae) from the Andean region of Colombia

Abstract The imago and soldier castes of a new Rugitermes Holmgren, 1911 species, R. tintosp. nov. are described. It is the ninth species of Rugitermes from South America and the first record of this genus from Colombia. Unlike its congeners, the soldier of R. tinto has very dark head capsule pigmentation and acute protuberances projecting from frontolateral ridges.

In South America, only four kalotermitid genera have soldiers with virtually no head capsule phragmosis: Comatermes, Incisitermes, Neotermes, and Rugitermes (Scheffrahn, 2019a). In his generic description, Krishna (1961) wrote that the Rugitermes soldier can be differentiated from the other three genera by the former's "prominent ridge…present in front of and medial to the antennal socket". The Rugitermes imago is distinguished by its "short, sclerotized median vein in the forewing which joins the radial sector very close to the wing suture" (Krishna 1961). The coloration of the head and pronotum contrast sharply in the majority of species.
Herein, we describe the imago and soldier of Rugitermes tinto sp. nov. This is the first record of Rugitermes from Colombia.

Material and methods
Microphotographs were taken as multi-layer montages using a Leica M205C stereomicroscope controlled by Leica Application Suite version 3 software. Preserved specimens were taken from 85 % ethanol and suspended in a pool of Purell Hand Sanitizer to position the specimens on a transparent Petri dish background.  Diagnosis. The soldier of R. tinto is the only non-phragmotic kalotermitid worldwide with dark coloration of the anterior head capsule. Aside from head color, it differs from congeneric soldiers in that the anterolateral corners of the frontal ridges project to form acute angles. In other South American (Fig. 4), Central American, and Oceanian Rugitermes, the anterolateral corners of the frontal ridges are either at right or obtuse angles.
Among South American species, the imago of R. tinto, with contrasting coloration of the head and pronotum, is similar to R. bicolor, R. flavicinctus, R. magninotus, and R. nodulosus. Of these, the imago of R. bicolor is larger, while that of R. flavicinctus is smaller than R. tinto and the head/pronotum coloration of the former two are similar to R. magninotus. The imago of R. magninotus has a brown head and a yellow pronotum while the imago of R. tinto has a black head and a brownish pronotum. The distribution of R. nodulosus is known only from southern Brazil (Minas Gerais).
Description. Imago ( Fig. 2A, B). Single female damaged: distal half of left wings torn, right wings absent. Head capsule black; pronotum brownish orange. Compound eye small, nearly circular. Ocellus very small, circular, black; difficult to see as there is no contrast with  head capsule cuticle; ocellus well removed from eye margin. Head vertex and frons not depressed; frons with faint rugosity; covered with dozens of erect setae ca 0.15-mm-long. Pronotum slightly wider than head capsule; anterior margin slightly incised; posterolateral corners evenly rounded, posterior margin narrowly concave. Pronotum pilosity congruent with vertex. Antennae with at least 16 articles, basal article relative lengths 1>2=3>4. Forewing anterior half as per genus; median vein very short, joins radial 0.9 mm from wing scale. Wing scale covered with about 20 setae of similar length and density as those on head and pronotum. Wing membrane smokey brown, covered with darker nodules. Legs dark brown. Arolium present. Measurements (maximum, mm): head width 1.31, pronotum width 1.43, eye diameter 0.32, ocellus diameter 0.01, and body length 7.9.
Soldier (Figs 2C, D, 3). Head capsule, in dorsal view, dark castaneous brown from posterior margin of postclypeus to posterior one fourth; posterior one fourth grading from dark reddish brown to brownish orange at occiput. In ventral view, head capsule coloration grades gradually from dark castaneous brown to brownish orange with exception of postmentum which remains dark reddish brown at posterior. Pronotum yellowish with reddish interior, in obvious contrast with head capsule coloration. Head capsule long, rectangular; lateral margins very slightly concave in middle, covered with a few setae except at frons where setae are denser. Pronotum much wider than long; with scattered setae, denser along lateral margins; anterior margin weakly incised. In dorsal view, the frontal flange forms a weak hemispherical border surrounding the frons. The frontal flange forms a 30° angle with plane of vertex. Frons finely rugose. In dorsal view (Fig. 2C) Type material examined. Holotype (soldier). Colombia: Risaralda, Pereira (4.810, -75.695); 1410 meters a.s.l., 11APR1998, J. Navarro, A. Arevalo; two soldiers (one labelled holotype), one damaged female imago University of Florida Termite Collection (UFTC) no. CO919, subsample from Colección Entomológica Forestal Universidad Distrital "Francisco José de Caldas" (CEFUDFJC) no. 009942 of which remains one soldier and three pseudergates.
Etymology. "Tinto" is the Colombian name for plain black coffee which is reminiscent of the dark coloration of the R. tinto soldier head capsule. The type locality of R. tinto, Pereira, is also in the major coffee growing area of Colombia.

Discussion
Authoritative records of the kalotermitid diversity for Colombia are reported almost entirely from the Caribbean Region (Casalla et al. 2016a, b;Snyder 1925;Krishna and Emerson 1962;Scheffrahn 2019a, b). An Andean termite survey by Parra and Soto (1992) is a remarkable exception as they report ten kalotermitids from this region. Except for Cryptotermes brevis (Walker), their generic and specific assignments are mostly incorrect. Furthermore, the drawings by Parra and Soto (1992) do not allow for positive identification below family. Aside from R. tinto and C. brevis, the only other confirmed kalotermitid from Andean Colombia is Glyptotermes truncatus (Krishna & Emerson, 1962).
It is hoped that future termite collecting in Andean Colombia will uncover many new termite species and expand known species distribution records. The Magdalena River Valley recently also yielded a new non-kalomitid termite, Rhynchotermes armatus Scheffrahn (2019c).

Acknowledgments
We thank J. Navarro, A. Arevalo, and A. Moreno for collecting this remarkable termite under institutional collection permit 038 -2014 of the Colección Entomológica Forestal "Universidad Distrital "Francisco José de Caldas" (no. 045 in the Colombian national collection registry).