Nasutitermes aurantius Scheffrahn, 2025

Scheffrahn, Rudolf H., Wang, Menglin, Bourguignon, Thomas, Rocha, Mauricio M., Cancello, Eliana M., Roisin, Yves & Hellemans, Simon, 2025, Nasutitermes aurantius (Isoptera, Termitidae, Nasutitermitinae), a new nasutiform termite species from Panama and a key to soldiers of Central American Nasutitermes Dudley, 1890, ZooKeys 1256, pp. 163-177 : 163-177

Nasutitermes aurantius Scheffrahn sp. nov.

Diagnosis.

The soldier of N. aurantius sp. nov. is unique among Central American Nasutitermes spp. by its small size and orange head capsule coloration. Among South American Nasutitermes , the N. aurantius soldier is closest in size and coloration to Nasutitermes jaraguae (Holmgren, 1910) , but the former has a proportionally longer and thinner nasus. The worker EVA of N. aurantius is unique among Neotropical Nasutitermes spp. in that the distal cushion sections are sclerotized, ovoid, granulated, and spiny. The imago of N. aurantius is the smallest among Central American Nasutitermes spp. as measured by head width.

Description.

Imago (Fig. 2 A ). Female unknown. Head capsule dark brown at vertex, gena lighter; clothed in dense setae of varying length. Fontanelle a narrow slit. Eyes nearly circular; projecting nearly half their diameter. Ocellus hyaline; more than one diameter from eye margin. Pronotum concolorous with head capsule; anterior margin straight, posterior margin slightly incised; setation as with head capsule. Antennae with 15 articles, formula 2> 3 <4 = 5, third article narrowest. Measurements (mm, N = 2, males): Head length to tip of labrum 1.23, 1.28; head maximum width with eyes 1.21, 1.25; eye maximum diameter 0.31, 0.35; ocellus maximum diameter 0.10, 0.11; pronotum maximum length 0.56, 0.59; pronotum maximum width 0.94, 95; right forewing length from suture 9.37, 9.94; total length with wings 11.36, 11.64.

Soldier (Figs 3 , 8 B ). Monomorphic. Head capsule orange with brown tinge, nasus darker. Head capsule subtriangulate in dorsal view; sides converging rather steeply toward nasus; slight constriction behind antennal sockets. Lateral view of head capsule with slight convexity above and behind antennal sockets. Vertex with four long setae near summit of convexity and two long setae near posterior third of vertex. Nasus narrowly conical with conspicuous setae at tip; nasus nearly parallel with lower margin of gena. Antennae with 13 articles, formula 2 <3> 4 <5. Mandibles with prominent points. Pronotum with shallow lobes angled 120 °; margin of dorsal lobe with a few long and numerous very short setae. Tergites with several long setae on posterior margins and many short setae in interior. Postmentum occupies nearly one-fourth of total head height with shallow convexity in lateral view opposite of vertex concavity. Measurements (mm, N = 10, X ̄, range): Head length 1.53 (1.46–1.58); head length to base of nasus 0.91 (0.86–0.94); nasus length 0.62 (0.57–0.67); maximum head width 0.84 (0.77–0.89); pronotum width 0.44 (0.40–0.49); hind tibia length 0.86 (0.86–0.91).

Worker (Figs 4 , 5 , 6 , 8 B ). Dimorphic. Head capsule light yellowish or light orangish; clothed with about 80 setae of varying lengths. Vertex with concavity behind postclypeus; postclypeus small, with steep posterior margin in lateral view. Fontanelle hyaline, large, ovoid; brain conspicuously white with incision carved out by fontanelle. Antennae with 14 and 13 articles for major and minor morph, respectively; antennal article formula 2> 3 <4 = 5 for both. Mandible dentition (wood feeding type) and gap between third marginal tooth and molar prominence similar for both morphs; left mandible with straight cutting edge; molar plate with ridges. Mesenteron well developed forming a complete ring from crop to P 1; P 1 long, tubular in dorsal and ventral views; forming an “ S ” from M to EVA seating visible through cuticle. Enteric valve armature composed of three cushions, each with anterior section consisting of about 80 to 100 rounded scales each with minute points facing posteriorly. Posterior sections of EVA sclerotized and ovoid; each formed with about 10–12 polygons; central 4–5 polygons granulated and each adorned with a spine; a few scattered scales between and anterior to cushions. Head width measurements (mm, N = 10 for each morph): major worker 1.04 X ̄ (range 99–1.04); minor worker X ̄ 0.87 (range 0.84–0.91).

Type material.

Holotype: Panama • Soldier; Coclé, Omar Torrijos Herrera National Park (El Cope) ; 8.66969°, -80.59302°; 791 m a. s. l.; 4 June 2010; R. Scheffrahn leg.; many soldiers (one labeled holotype) and workers; University of Florida Termite Collection ( UFTC) no. PN 1315 . Paratypes: Same data as holotype; two subsamples from separate colony; two male alates, many soldiers and workers, five nymphs ( PN 1317 ); many soldiers and workers, two nymphs ( PN 1316 ) .

Etymology.

The specific name “aurantius” is from Latin “aurantium” meaning “orange”, referring to the soldier’s head capsule coloration.

Ecological note.

Nasutitermes aurantius sp. nov. foragers and two alates were collected underneath saturated decaying wood (Fig. 8 ). No above-ground nest structure was observed, so it is assumed that the nest is subterranean. The presence of developed alates suggests that the flight season is in early June. The type locality is classified as tropical rainforest (Köppen-Geiger) with an annual precipitation of> 250 cm.

Taxonomic note.

Light (1933) described two additional Central American Nasutitermes species from the imago caste: N. pictus and N. colimae . Both were collected simultaneously during a single dispersal flight by M. Ceballos from an “old orange tree” in Colima, Mexico. No foragers were collected. Their large size (head width 1.65 and 1.95, respectively) suggests that these two species are not Nasutitermes but either a Cahuallitermes spp. (imago unknown), a Tenuirostritermes spp. , or an undescribed apicotermitine. Therefore, we consider N. pictus Light, 1933 and N. colimae Light, 1933 to be nomina dubia.

Figures

Figure 2. Alate of Nasutitermes aurantius sp. nov. (PN 1317, male). A. Dorsal habitus; B. Dorsal view of head capsule and pronotum; C. Lateral view of head capsule and pronotum.

Figure 3. Soldier of Nasutitermes aurantius sp. nov. (PN 1315). A. Dorsal view of head and pronotum; B. Lateral view; C. Ventral view; D. Lateral habitus.

Figure 4. Worker of Nasutitermes aurantius sp. nov. (PN 1315). A. Dorsal view of major worker; B. Dorsal view of minor worker; C. Ventral view of major worker.

Figure 5. Worker of Nasutitermes aurantius sp. nov. (PN 1315). A. Dorsal view of major worker head capsule; B. Lateral view of same; C. Major worker mandibles (3 M = third marginal tooth, MP = molar prominence); D. Minor worker mandibles.

Figure 6. Enteric valve armature of the major worker of Nasutitermes aurantius sp. nov. (PN 1315). Inset shows a close-up of the posterior cushion.

Figure 8. Field habitus of Nasutitermes aurantius sp. nov. A. Alate (PN 1317); B. Foragers (PN 1315; note microsporidial infection in abdomen of worker at bottom right).