Cryptotermes cubicoceps ( Emerson, 1925 )

Scheffrahn, Rudolf H., 2024, Cryptotermes cubicoceps (Emerson, 1925) (Isoptera: Kalotermitidae), redescription of a lost Guyanese termite, Zootaxa 5437 (1), pp. 121-124 : 122-124

Cryptotermes cubicoceps ( Emerson, 1925)

Kalotermes (Cryptotermes) cubicoceps Emerson, 1925: 330–331 (soldier), figs. 31d–e

Type locality. British Guiana; Kartabo (58° 42’ W, 6° 23’ N)

Imago ( Figs. 2A–B ). First description. Head capsule and pronotum pale yellow. Compound eye small, ellipsoid. Ocellus very faint light yellow, about half diameter of eye, roundly ellipsoid; nearly touching eye margin. Vertex with a few very short setae. Pronotum as wide as head with eyes; anterior margin shallowly concave, posterior margin concave near middle. Pronotum lateral margins each with about one dozen setae of various lengths. Antennae with 14 articles, basal article relative lengths 2=3>4=5. Wing membrane hyaline, veins pale yellow. Fore wing with costa, subcostal, radius, and radial sector sclerotized; unsclerotized media terminating at radial sector about two thirds wing length from suture. Arolium present.

Measurements (mm, mean, n=2). Head maximum width with eyes 0.89; head max. width without eyes 0.79; pronotum max. width 0.88; eye max. diameter 0.26; total body length 4.00; right forewing length from scale 6.25; body length with wings 7.40.

Soldier ( Figs. 3 A–F ). Head, in lateral view, pale orange along the ventral half of a diagonal line from the posterior vertex almost to the antennal sulcus; dorsal to this region quickly grading to black. Anterior margin of pronotum light brown, grading to hyaline at posterior. In dorsal view ( Fig. 2A ), posterior margin of head capsule truncate, lateral margins parallel; frontal flange evenly concave, slightly elevated. Anterolateral corners of flange form rounded knobs; frontal horns form thumb-like projections between the flange corners and mandible bases. In lateral view ( Fig. 2B ) frontal horns hemispherical; eyespots faintly visible. In oblique view ( Fig. 2C ) vertex concave, less rugose than frons; frons and postclypeus very rugose. Frontal flange incised in posterior and ventral view ( Figs. 2E–F ). Head capsule with two posterior setae; pronotum with about eight setae of various lengths along lateral margins. Posterior margin of pronotum evenly serrated, upturned; incised in congruence with flange; posterior margin barely concave. Genal horns barely developed and posterior to frontal horns. Mandibles short, wide, with weak dentition; outer margins angled about 45°; basal humps lacking. Labrum very short and narrow; translucent. Antennae white, with 12 articles; basal formula 2>3=4<5.

Measurements in mm, of the single neotype soldier. Comparable measurements by Emerson (1925) in parentheses: Head length to tip of mandibles 1.41 (2.65); head length to tip of frontal horns 1.23, frontal flange width 1.01; frontal horns, outside span 0.81; genal horns, outside span 0.94; head width, maximum 1.07 (2.12); head width, minimum (behind frontal horns) 1.06; head height, excluding postmentum 0.86; pronotum, maximum length 0.67 (1.23); pronotum, maximum width 0.91 (1.88); left mandible length, tip to ventral condyle 0.59; hind tibia length 0.57 (1.25) total length 3.30 (5.88).

Material examined. Neotype soldier, two winged imagos in UFTC vial no. TT2383. Vial in the UFTC labelled “ Trinidad and Tobago, Chacachacare island; 10.693, -61.752; JPEC Darlington col.; 30-Mar-1990 ”.

Diagnosis. Of Neotropical Cryptotermes , the imago of C. cryptognathus Scheffrahn & Křeček, 1999 , is similar in head capsule coloration and wing length to C. cubicoceps . The soldier of C. cubicoceps is unique among all other South American congeners in having a cuboidal head capsule, projecting thumb-like frontal horns, and a very rugose postclypeus. Cryptotermes contognathus Constantino (2000) has projecting frontal horns, but the mandibles are much shorter than those of C. cubicoceps and the postclypeus is not rugose.

Remarks. Comparable measurements of C. cubicoceps given by Emerson (1925) are all about twice those of the neotype soldier and much larger than any Cryptotermes worldwide ( Bacchus 1987, Scheffrahn & Křeček 1999). I suspect that this was the result of a conversion error from Emerson’s reticule scale to actual measurements. The locality of the neotype and lost holotype are 580 km apart but both were part of the greater Trinidadian land shelf during the last glacial maximum.

In Emerson’s 1925 description of the lone C. cubicoceps soldier he states “When collected I thought that it belonged to a colony of the species I am describing as Kalotermes (Glyptotermes) pellucidus , n. sp. although I did not see it with any termites. As the imago, however, has the characteristics of the subgenus Glyptotermes and the soldier does not, I think that they must be separate species”. Emerson (1925) collected imagos of G. pellucidus twice. His description is based on eight alates, collected from lights, with venation consistent for Glyptotermes (costal margin, radial sector, and median parallel and close together, his fig. 31c). Emerson reported an anterior wing length of 5.76–5.88 mm for G. pellucidus . The anterior wing length of the smallest Cryptotermes species reported in Scheffrahn and Krecek 1999 is that of C. abruptus at 6.25 mm long, identical to that of C. cubicoceps herein.

I conclude that Bacchus (1987) mistakenly redescribed the G. pellucidus dealate which he believed was that of C. cubicoceps . Bacchus (1987) based his description on the single dealate that was in the vial of the missing C. cubicoceps soldier ( Fig. 1 ). Bacchus’ description of the C. cubicoceps dealate closely matches the G. pellucidus description by Emerson (1925) for corresponding characters: head coloration (yellowish-brown vs. brownish yellow, respectively); pulvillus/arolium present; maximum width of head (0.91 vs 0.88–0.94 mm); eye diameter (0.31 vs 0.27–0.29 mm); and maximum width of pronotum (0.81 vs. 0.82–0.85 mm).

Figures

FIGURE 1. Emerson’s 1925 original label of Cryptotermes cubicoceps (top) and the label of Bacchus (1987).

FIGURE 2. Head capsule and pronotum of Cryptotermes cubicoceps imago: A) dorsal, B) lateral views.

FIGURE 3. Head capsule of the soldier of Cryptotermes cubicoceps.:A) dorsal, B) lateral, C) oblique frontal, D) posterior, E) ventral, and F) ventral oblique view of anterolateral margin (FF = frontal flange, FH = frontal horn, GH = genal horn, RM = right mandible).