Cubitermes bilobatus, Haviland, 1898, Josens & Deligne, 2019

Josens, Guy & Deligne, Jean, 2019, Species groups in the genus Cubitermes (Isoptera: Termitidae) defined on the basis of enteric valve morphology, European Journal of Taxonomy 515, pp. 1-72 : 30-33

1. The bilobatus valve pattern group

The workers within this pattern have basic enteric valves: all six primary cushions (PCs) are similar in their arrangement ( Fig. 12A ). In the upstream and middle spiny parts, they are armed with relatively strong spines, becoming gradually thinner downstream; moreover, the middle part bears some lateral supporting spindle-like bristles leaning on the funnel membrane. In the downstream bristly part, the spines are rather abruptly replaced with longer and bristle-like setae, first straight, then curved and eventually hooked. The PCs are roughly triangular: their largest width is generally located near their upstream end and their lateral margins converge gradually downstream until the bristly part where they remain parallel ( Fig. 11A ). The enteric valve shows hexaradial to triradial symmetry, the odd PCs often being somewhat longer than the even PCs. In some cases, PC1 is still longer than PC3 and PC5, tending towards bilateral symmetry.

An odd primary cushion ( Fig. 11A ) is made of (a) a long, upstream, spiny part (38–58% of total length) with relatively strong spines, (b) a short, middle, spiny part (8–15% of total length) with somewhat weaker spines and with few lateral supporting bristles (3–6 on each side), and (c) a long, downstream, bristly part (27–49% of total length) with 15–50 straight or curved short bristles and possibly a few hooked ones ( Fig. 11A ).

The secondary cushions (SCs) are also armed upstream with spines (less robust than on the primary cushions) and downstream with short bristles; the SCs are wide at the upstream end, narrowing noticeably downstream, in most species with a heterogeneous scattering of the spines (the spines are lacking in some irregular spots) ( Fig. 12A ), more rarely with a homogeneous scattering of the spines.

In the soldier’s enteric valve, the primary cushions are barely or not at all outlined ( Fig. 12B ); the lateral supporting bristles are very short or absent and there are few bristles on the downstream end. The secondary cushions are like those of workers but bear less developed spines.

This basic valve pattern is therefore characterised by scarcely developed valves, with very few (± 6) supporting bristles on each side of the PCs and generally heterogeneous spines scattering on the SCs; all of the species are small.

Material examined

Ten taxa have such enteric valves:

Figures

Fig. 12. A. Enteric valve of the “bilobatus valve pattern”, from a worker of Cubitermes bilobatus (Haviland, 1898): note the irregular scattering of the spines of the secondary cushions; B. Idem from a soldier of C. bilobatus; C. Geographical distribution of the species with the bilobatus valve pattern.

Fig. 11. Representative primary cushions of the various patterns encountered in the workers of the genus Cubitermes; WVPD = downstream bristly part; WVPM = middle spiny part; WVPS = spatula; WVPU = upstream spiny part. A. PC1 of the bilobatus valve pattern. B. PC1 of the oculatus valve pattern. C. any odd PC of the bilobatodes valve pattern. D. PC1 of the muneris valve pattern. E. PC6 and PC1 of the fungifaber valve pattern. E’. PC3 of the fungifaber valve pattern, twisted and partly seen in profile. F. PC1 of the finitimus valve pattern. F’. PC3 of the finitimus valve pattern, twisted and seen in profile. G. PC3 of the sankurensis valve pattern. H and H’. PC3 and PC4 of the oblectatus valve pattern. I. Any PC of the sulcifrons valve pattern. I’. Any PC of the sulcifrons valve pattern, twisted and seen in profile. All drawings to the same scale.