Bolton, B., 2011:
(Figs 55 – 57)
WORKER (holotype in parentheses). Measurements: HL 0.66 – 0.72 (0.68), HW 0.52 – 0.58 (0.55), HS 0.590 – 0.650 (0.615), SL 0.48 – 0.52 (0.52), PrW 0.42 – 0.46 (0.46), WL 0.94 – 1.02 (0.96), HFL 0.52 – 0.58 (0.55), PeNL 0.20 – 0.22 (0.22), PeH 0.48 – 0.53 (0.49), PeNW 0.38 – 0.41 (0.40), PeS 0.360 – 0.383 (0.370) (14 measured). Indices: CI 79 – 83 (81), SI 86 – 96 (95), PeNI 85 – 95 (87), LPeI 40 – 46 (45), DPeI 182 – 200 (182).
Eyes absent or a small and inconspicuous eye spot present that is often difficult to see against the punctate side of the head. Apex of scape, when laid straight back from its insertion, just fails to reach the midpoint of the posterior margin in full-face view; SL/HL 0.70 – 0.76. Cephalic dorsum sharply reticulate-punctate. Pronotal dorsum almost smooth, with spaced, minute, superficial punctures, obviously much less strongly and densely sculptured than cephalic dorsum. Metanotal groove absent from dorsum of mesosoma. Mesonotal-mesopleural suture feebly present on side of mesosoma. Propodeum distinctly marginate between declivity and side. Posterior surface of petiole node without short cuticular ridges that radiate upward from the peduncle. Node of petiole in profile tall and relatively thick, the dorsum weakly convex. Subpetiolar process with a distinct ventral angle. Petiole node in dorsal view very broad. Maximum width of first gastral tergite in dorsal view distinctly greater than the width of the second gastral tergite at its midlength. Base of cinctus of second gastral tergite glossy and polished, without trace of cross-ribs. Midline length of second gastral posttergite, from posterior margin of cinctus to apex, is less than the width of the segment at its midlength. Disc of second gastral tergite with sharply incised, small punctures that are widely separated by areas of glossy cuticle; the diameters of the punctures are distinctly less than the distances that separate them. First and second gastral tergites dorsally pubescent and with a number of short standing setae that conspicuously project above the level of the pubescence in profile. Full adult colour dark reddish brown.
Holotype worker, Gabon: Prov. Ogooue-Maritime, Res. Monts Doudou, 24.3 km. 307° NW Doussala, 2°13.4 ’ S, 10°24.4 ’ E, 375 m., 9.iii.2000, #2200(48)-6, sifted litter (leaf mold, rotten wood) rainforest (B.L. Fisher) (CASC). Paratypes. 8 workers (of which one is teneral and lacking its head), 1 worker-queen intercaste (teneral) and 3 dealate queens, with same data as holotype and all in series #2200; individual pins coded (10)-5, (11)-7 (queen), (11)-8, (13)-4 (queen), (14)-8, (15)-13, (23)-4, (45)-4 (worker and queen on one pin), (45)-6 (intercaste), (47)-4, (49)-4 (CASC, BMNH).
The paratype intercaste has about 12 ommatidia in the eye compared to the holotype, where the eye is a mere spot, and to a genuine queen where the eye has> 50 ommatidia. Also, the intercaste has PeNI 100 (holotype 87, paratype queen 88), and maximum width of first gastral tergite in dorsal view 0.64 (holotype 0.59, paratype queen 0.64). The dealate queen has a full complement of flight sclerites, not developed in the intercaste.
This species is very closely related to occidentalis . Their descriptions are very similar and most of their dimensions fall within the same ranges. However, the petiole node in importuna is usually strikingly transverse in dorsal view and averages broader both in relation to the width of the pronotum and to the length of the node. In occidentalis PeNI is 76 – 89 (mean value of 82), and DPeI is 150 – 180 (mean value of 165). By comparison, importuna has PeNI 85 – 95 (mean value of 91) and DPeI 182 – 200 (mean value of 190). H. comis also has a broad petiole, reminiscent of importuna , but the size and detailed structure of their petioles differ, as noted in the key; see also under comis for other differentiating characters.
Two Kenyan specimens from Bunyangu Nature Reserve (ZFMK, details below) are intercastes. One of them has eyes with 7 – 8 ommatidia but the other is odd, because the right eye is minute while the left is much larger and consists of an indeterminate number of fused ommatidia.
Non-paratypic material examined. Gabon: Res. Monts Doudou, Doussala (B.L. Fisher). Central African Republic: P.N. Dzanga-Ndoki, Lidjombo (B.L. Fisher). Kenya: Western Prov., Kakamega For., Colobus (G. F is -cher ); Kakamega For., Yala (G. F is c h e r); Yala River Nat. Res. (Snelling & Espira); Kakamega For., Isecheno (R.R. Snelling); Isecheno For. Res., Kalunya Glade (R.R. Snelling); Bunyangu Nat. Res. nr Salazar Circuit (Snelling & Espira).