Disjunctitermes insularis Scheffrahn

Scheffrahn, Rudolf H., Carrijo, Tiago F., Postle, Anthony C. & Tonini, Francesco, 2017, Disjunctitermesinsularis, a new soldierless termite genus and species (Isoptera, Termitidae, Apicotermitinae) from Guadeloupe and Peru, ZooKeys 665, pp. 71-84 : 71-73

Disjunctitermes insularis Scheffrahn sp. n.

Material examined.

Holotype: labelled "(UF code GU 105) GUADELOUPE Basse-Terre, Trail Mamelles de Petite Bourg. Parc Nat., undisturbed forest, 16.1778; -61.7321, 23MAY99, col. Chase, Krececk, Maharajh, Mangold, and Scheffrahn. Paratype colonies (the holotype is kept in the same vial as the paratypes): GUADELOUPE, Basse-Terre 16.1778; -61.7321, 23MAY1999 (GU106), 12 workers; 16.1814; -61.7361, 29MAY1999 (GU753), 12 workers; 16.1814; -73.61, 29MAY1999 (GU754), 11 workers; 16.1674; -61.6644, 29MAY1999 (GU783), 12 workers; 16.1674; -61.6644, 29MAY1999 (GU784), 12 workers; 16.1674; -61.6644, 29MAY1999 (GU785), 12 workers; 16.1674; -61.6644, 29MAY1999, (GU786), 12 workers; 16.1674; -61.6644, 29MAY1999, (GU787), 12 workers; 16.1674; -61.6644, 29MAY1999, (GU788), 12 workers. PERU, 6 km S von Humboldt, disturbed forest, -8.8769; -75.0465, 28MAY2014 (PU505), 12 workers, col. Carrijo, Chase, Constantino, Mangold, Mullins, Křeček, Kuswanto, Nishimura, and Scheffrahn. All material housed at the University of Florida Termite Collection in Davie, Florida. Collection sites are mapped in Fig. 4.

Diagnosis.

See also comparison for Disjunctitermes above. The EV pads of D. insularis differ from those of the four other described species with unarmed EV as follows (Fig. 3): each pad of A. banksi is vase-shaped, with a narrow posterior end that widens into an oval base reminiscent of an orb-weaving spider web (Fig. 3C); the A. pacificus pads are shaped similarly to those of A. banksi but are less concentric and are adorned with a few unsclerotized spines (Fig. 3E); while the pads of H. arienesho and H. kawaii are ovoid in shape (Figs 3F and 3G, respectively).

Imago.

Unknown.

Worker

(Figs 1-3, Table 2). See Disjunctitermes gen. n. description above. EV devoid of sclerotized spiny armature. Pads about six times longer than wide; slight difference in length when stretched horizontally. Anterior fourth of each pad composed of about 10-20 ovoid scales each with one point facing posteriorly. Posterior portion of pads truncate with about 30-50 polygonal scales adorned with fringes on their posterior margins. Cuticle between pads with about 15-20 faint arching ridges; ridges fringed posteriorly.

Etymology.

The species name is derived from its unexpected island locality.

Habitat and biology.

Workers were collected in foraging groups under rocks and stones in rainforest habitats. Like many New World Apicotermitinae, D. insularis does not build any above-ground structures. Mature worker gut contents confirm that they feed on the organic fraction of soil.

Molecular phylogeny.

The molecular phylogeny performed with the mitochondrial gene COI clearly clustered D. insularis specimens from Guadeloupe and Peru, as well as specimens belonging to the same species of other genera (Fig. 5). However, the phylogeny showed low resolution in the relationships between the Apicotermitinae genera.

Dispersal rate on land.

Starting from a single founder location, the stochastic spread models predicts a 2,778-meter spread over 85 years (Fig. 6) or about 265 years to reach the ca. 8 km expanse between the easternmost and westernmost collection localities (Fig. 4). This suggests a very remote possibility that a single human transport event delivered D. insularis to Guadeloupe which would have taken place at a time when French colonization of Basse-Terre was limited to the coast ( Hoy 1961). It is far more likely, however, that D. insularis reached Guadeloupe via a natural overwater dispersal event ( De Queiroz 2005) during pre-Colombian times.

Taxonomic correction.

Darlington (1992) reported a Neotermes sp. between 600-1000 m on Basse-Terre which we found to be Comatermes perfectus (Hagen).