Tuesday, April 18, 2017

[Entomology • 2017] Disjunctitermes insularis • A New Soldierless Termite Genus and Species (Isoptera, Termitidae, Apicotermitinae) from Guadeloupe and Peru


Disjunctitermes insularis  
Scheffrahn, Carrijo, Postle & Tonini, 2017 


Abstract
Disjunctitermes insularis gen. n. & sp. n. is described from workers collected on Guadeloupe and in Peru and is the first soldierless termite found on a deep-water island. As with many soldierless and soil-feeding termite species, the enteric valve morphology is an essential diagnostic character of D. insularis. The D. insularis sequence cluster, derived from a barcode analysis with twelve other described genera of New World Apicotermitinae, is well resolved. Results of a stochastic dynamic spread model suggest that the occurrence of D. insularis on Guadeloupe may be the result of a pre-Colombian overwater dispersal event from mainland South America.

Keywords: Soil-feeder, taxonomy, barcode sequence, stochastic spread, overwater dispersal

Figure 1. Dorsal (A) and lateral (B) views of the Disjunctitermes insularis worker head capsule
C Dorsal views of newly molted worker mandibles of Anoplotermes banksi Emerson (top) and D. insularis (bottom)
D Ventral views of the molar portion of the left mandibles of newly molted workers of A. banksi (top) and D. insularis (bottom) E Right fore-tibia, and F right lateral view of D. insularis worker. 

Disjunctitermes Scheffrahn, gen. n.

Diagnosis: Disjunctitermes is one of the described Neotropical apicotermitines that, along with Anoplotermes banksi, A. pacificus, and Hydrecotermes spp., possess strongly inflated fore tibia and lack spiny sclerotized enteric valves. Disjunctitermes is closest to A. banksi, but can be distinguished from the latter by the subsidiary tooth on the left mandible, the larger EV seating and the more truncate terminus of P2 (Fig. 3C, D). Hydrecotermes lacks a spheroidal mesenteric tongue.

Etymology: The genus name is derived from its current, widely disjunct distribution on Guadeloupe and Peru.


Disjunctitermes insularis Scheffrahn, sp. n.

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).

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.

 Rudolf H. Scheffrahn, Tiago F. Carrijo, Anthony C. Postle and Francesco Tonini. 2017. Disjunctitermes insularis, A New Soldierless Termite Genus and Species (Isoptera, Termitidae, Apicotermitinae) from Guadeloupe and Peru. ZooKeys. 665; 71-84. DOI: 10.3897/zookeys.665.11599



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