Schievitermes, Roisin, 2022

Roisin, Yves, 2022, Schievitermes globicornis, a new genus and species of Termitinae (Blattodea, Termitidae) from French Guiana, ZooKeys 1125, pp. 103-114 : 103

Schievitermes gen. nov.

Remark.

This genus is presently monotypic.

Type species.

Schievitermes globicornis sp. nov.

Description.

Imago: only known from a single queen. See species description.

Soldier (Figs 1 - 4 ): Head capsule (Figs 1-3 ) subquadrangular with rounded corners, about twice as long as broad, bearing numerous (~100) setae. Mandibles approximately as long as head capsule, rather thick, of the snapping type. Right mandible almost straight, only slightly curved inwards. Left mandible slightly but distinctly sinuous: outer margin slightly concave near base, convex in middle, then concave again at level of contact with right mandible, then curved inwards at tip. Tips of both mandibles hooked, turned about 60° inwards. Antennae of 13 articles, apical article reaching beyond left mandible tip; article 3 distinctly globular, as broad as article 1 and broader than all other articles. Labrum (Fig. 4 ) with nearly parallel sides, anterior margin sinuous, convex in middle, bearing a few long bristles, anterior corners rounded. Frons without projection.

Worker (Figs 5 - 9 , 12-13 , 15-17 ): Monomorphic. Head capsule whitish, bearing many setae. Mandibles (Fig. 5 ) of the wood-feeding type. Left mandible: distance between teeth A-M1+2 approximately half the distance M1+2-M3. M3 well-marked, premolar tooth (sensu Deligne 1999) blade-like, molar ridges well developed. Right mandible: distance between teeth A-M1 short, M2 well-marked, molar ridges well developed. Crop moderately developed, gizzard (Figs 6 , 7 ) of the generalized type ( Noirot 2001), cuticular armature limited to small pectinated scales on the pulvilli (Fig. 7 ). Mixed segment long, mesenteric tongue bilobate distally (Fig. 8 ). Ileum (P1) slightly dilated, narrowing into P2. Enteric valve (P2) funnel-like, conical at end of P1, becoming a narrow tube at junction with P3. Enteric valve armature (Fig. 9 ) consisting in two rings of spine-bearing areas, the proximal one in the conical section of P2, formed by three ovoid cushions alternating with elongated ones, all bearing small triangular spines; distal ring within the narrow tubular section, formed by six alternating short and long cushions bearing thin, curved spines. Paunch (P3) voluminous, with wall bearing numerous small spines, longer in rounded posterior section near entrance of P2 (Fig. 12 ), short and often pectinated in anterior section narrowing towards P4 (Fig. 13 ).

Etymology.

From local Brussels dialect schieve = not straight, askew, and Latin termes = termite. The name refers to the slight grade of asymmetry displayed by soldier mandibles.

Diagnosis.

Soldier: Among neotropical snappers, the absence of a frontal projection distinguishes Schievitermes from Termes , Inquilinitermes , Cavitermes , Palmitermes , Dihoplotermes , and Cornicapritermes . Planicapritermes has a characteristic flattened head capsule and strongly asymmetrical mandibles. Schievitermes differs from Crepititermes by its thicker mandibles with a slight, but distinct asymmetry, and globular third antennal article. Neocapritermes species are consistently larger (head width> 1 mm), have more antennal articles (15-16 vs 13) and their mandible asymmetry is always more pronounced ( Krishna and Araujo 1968; Constantino 1991; Bandeira and Cancello 1992).

Worker: Mandibles are of the wood-feeding type, as in Neocapritermes and Planicapritermes , with a short space between apical and anterior marginal teeth, and well-developed molar ridges. Termes (with the exception of the wood-feeding species, T. hispaniolae (Banks, 1918)), Crepititermes , Inquilinitermes , Cavitermes , Palmitermes , Dihoplotermes and Cornicapritermes have mandibles of the soil feeding type, with a broad space between apical and anterior marginal teeth, and reduced molar ridges. The digestive tube of Schievitermes is similar to that of Planicapritermes , but the bilobed apex of the mesenteric part of the mixed segment is distinctive. Neocapritermes also possesses two mesenteric lobes, but the mixed segment is shorter and the mesenteric lobes are larger and more widely separated ( Constantino 1998; Almeida-Azevedo et al. 2021). The enteric valve armature of Schievitermes is similar to that of Planicapritermes (Figs 10 , 11 ), apart from minor differences in the ornamentation of spiny areas. Cuticular differentiations within P3 of Schievitermes are intermediate between the long spines and filaments observed in Neocapritermes ( Noirot 2001) and the tiny spines present in Planicapritermes ( Noirot 2001; Fig. 14 ).

Most workers show signs of dehiscence between metanotum and first abdominal tergite, ranging from a short slit-like aperture bordered by brown sclerotic marks (Fig. 15 ) to a broad opening through which the whole anterior part of the gut protrudes (Figs 16 , 17 ).

Figures

Figure 8. Schievitermes globicornis sp. nov.: camera lucida drawings of worker gut in situ. From left to right: viewed from above, right, below, left. Mesenteron stippled.

Figures 1 - 3. Schievitermes globicornis sp. nov.: soldier head 1 from above 2 from below 3 from left.

Figures 4 - 7. Schievitermes globicornis sp. nov.: 4 labrum of soldier 5 worker mandibles, from above 6 gizzard of worker, complete, spread on slide (phase-contrast illumination) 7 gizzard of worker, detail of pulvillus (phase-contrast illumination).

Figures 9 - 14. Proctodeal wall ornaments under phase-contrast illumination 9 Schievitermes globicornis sp. nov., worker enteric valve, spread on slide 10, 11 Planicapritermes planiceps (Emerson, 1925), worker enteric valve, spread on slide; proximal spiny areas and detail of distal spiny ridges, respectively 12, 13 Schievitermes globicornis sp. nov., ornamentation of worker paunch wall, in bulbous posterior part and narrower anterior section, respectively 14 Planicapritermes planiceps, ornamentation of worker paunch wall.

Figures 15 - 17. Workers of Schievitermes globicornis sp. nov. fixed at various stages of abdominal dehiscence 15 linear crack (arrow) behind rear margin of metanotum 16 gut protruding through crack 17 anterior part of the gut completely extruded.