Cubitermes bilobatodes, Silvestri 1912, 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 : 35-36

2. The bilobatodes valve pattern group

The workers within this pattern have basic enteric valves: all six primary cushions are similar in their arrangement ( Fig. 13A ). In the upstream and middle spiny parts, they are armed with relatively strong spines becoming gradually thinner downstream; the middle part also 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 primary cushions are mainly fusiform: their largest width is located between the first upstream third and the middle, and their lateral margins converge gradually upstream and downstream ( Fig. 11C ). The odd PCs are longer than the even PCs, giving triradial symmetry to the valve ( Fig. 13A ).

An odd PC is made of (a) an upstream spiny part (27–51% of total length) with relatively strong spines, (b) a middle spiny part (24–47% of total length) with somewhat weaker spines and with 13–30 lateral supporting bristles on each side, and (c) a bristly part: (22–37% of total length) with 35–75 straight, curved and eventually hooked bristles ( Fig. 11C ).

The secondary cushions are either broad at the upstream end, narrowing noticeably downstream, with a homogeneous scattering of spines (as in Fig. 4E for the species from East and Southern Africa), or somewhat stalked, widening near the first third with a heterogeneous scattering of spines tending towards the shape of a spearhead ( Figs 4F , 13A for the species from West and Central Africa).

In the soldier’s enteric valve, the primary cushions are similar to those of the worker with triradial symmetry, the odd PCs being longer than the even PCs; the secondary cushions are broad and either homogeneous or with a tendency towards the shape of spearheads ( Fig. 13B ).

This basic valve pattern is therefore characterised by high alternation indices in both workers and soldiers and by fusiform odd PCs; most species are small- to medium-sized.

Material examined

Five species have such enteric valves:

Figures

Fig. 13. A. Enteric valve of the “bilobatodes valve pattern”, from a worker of Cubitermes bilobatodes Silvestri 1912: note the spearhead-shape of the secondary cushions; B. Idem from a soldier of C. bilobatodes; C. Geographical distribution of the species with the bilobatodes 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.

Fig. 4. A. Enteric valve (of C. oblectatus Harris, 1958), seen in profile with simplified pilosity. In this species, the primary cushions PC3 and PC5 bear not only spatulae (sp) but also crests (cr) near the downstream end. B. Section through an enteric valve, seen from upstream. Sands’ numbering of the cushions is inside; present numbering of the primary (PC1 to PC6) and secondary (SC12 to SC61) cushions outside. C. Measurements on PC1: WVP1UL = length of the upstream spiny part (it starts at the first spine and ends at the first lateral supporting bristle); WVP1ML = length of the middle spiny part (it starts at the first lateral supporting bristle and ends at the last lateral supporting bristle); WVP1DL = length of the downstream bristly part (it starts at the last lateral supporting bristle); WVP1W = maximal width. D. Measurements on PC4 (one of the PCs with spatula in the sankurensis valve pattern): WVP4SL = length of the downstream spatula part (this is also the part that sticks out of the valve when in function). Other symbols as in figure C. E. Measurements on SC12 in the case of a wide and homogeneous cushion (in the muneris valve pattern). F. Measurements on SC12 in the case of a heterogeneous spearheadshaped cushion (in the bilobatodes valve pattern). G. Measurements on SC12 in the case of a narrow cushion that becomes wider and fuzzy in its downstream part (in the oculatus valve pattern); in E, F and G, WVS12L = length of the secondary cushion (between the most extreme spines or bristles), WVS12W = width of the secondary cushion (between the most extreme spines or bristles in its upstream third).