Myrmecodesmus hastatus (Schubart, 1945)

GOLOVATCH, Sergei I., GEOFFROY, Jean-Jacques, MAURIÈS, Jean-Paul & VANDENSPIEGEL, Didier, 2016, Detailed iconography of the widespread Neotropical millipede, Myrmecodesmus hastatus (Schubart, 1945), and the first record of the species from the Caribbean area (Diplopoda, Polydesmida, Pyrgodesmidae), Fragmenta Faunistica 59 (1), pp. 1-6 : 2-3

The following M. hastatus samples from Martinique are kept in the Paris Museum collection:

Material examined. 1 juv.: Les Anses d’Arlet, under stones 0.5 km N of Anses d’Arlet , 11 Nov 1978 ; 3 juv.: Grand’Rivière , near beach, Anse Morne Rouge, dead tree, 20 Feb 1981, all leg. J.-M. Thibaud ; 3 females, 7 juv.: Gros-Morne, 6 km NE of Gros-Morne , forest between Morne Bellevue and Morne de l’Etang, 600–690 m a.s.l., dead leaves and wood, 11 Feb 1981 ; 1 juv.: Trinité, near île Caravelle, under dry log between l’Oratoire and meteo station, 80–115 m a.s.l., 12 Feb 1981 ; 29 juv.: Morne Rouge, Trace des Jésuites , right bank of Lorrain River , 400–500 m a.s.l., dead wood and bamboo, 13 Feb 1981 ; 8 juv.: Rivière-Pilote , Anse Figuier, under bark of Cocos palm lying on sand, 24 Feb 1981 ; 1 juv.: Grand’Rivière , path to Morne Macouba ( massif Montagne Pelée ), S of savanna Anatole, forest, 550–600 m a.s.l., dead wood and leaves, 26 Feb 1981 ; 4 females, 2 juv.: Grand’Rivière , Morne aux Gueules (path to Montagne Pelée ), cultivated land, 26.II.1981 ; 3 females: Fonds-Saint-Denis, Pitons du Carbet , between sides at 1100 and 1120 m a.s.l., SSE of Piton Boucher , bush savanna, mosses and dead wood, 27 Feb 1981, all leg. J.-P. Mauriès ; 2 males, 9 juv.: Saint-Pierre, rocks, sugar cane, 80 m a.s.l., 02 Mar 2015, leg. M. Coulis.

Remarks. As seen from the above records, M. hastatus is remarkably widespread on Martinique, ranging from nearly sea-level to mountain tops above 1100 m in elevation. Although there are no direct observations on the labels of its association with ants or termites, dead wood in the tropics is known to be widely populated and destroyed by termites.

Both available males were studied in detail to reveal the species identity. The results are presented in Figs 1–20 . There can be no doubt now that the Martinique samples belong to M. hastatus . The spinulate flagellum (fl) arising at the base of a simple, more or less sigmoid solenomere (sl) is especially characteristic ( Figs 14–17 & 20). SEM iconography demonstrates all features typical of a small cryptic pyrgodesmid, including a flabellate collum that fully covers the head from above, the differentiated tuberculations and lobulations on the metaterga, the porosteles, the well-developed cerategument on the metazonae, etc. However, only gonopod characters are decisive for a proper species determination.

This provides the first evidence of the presence of M. hastatus in the Caribbean.

Figures

Figs 1–17. SEM micrographs of a male of Myrmecodesmus hastatus (SCHUBART, 1945), from Saint-Pierre, Martinique: habitus, lateral view (1); anterior part of body, lateral and dorsal views, respectively (2 & 5); midbody segments, lateral view (3); caudal part of body, lateral, dorsal and ventral views, respectively (4, 6 & 7); metatergal microsculpture, caudal view (8); cross-section of a midbody segment, caudal view (9); midbody paratergite, lateral view (10); tergal microsculpture with limbus, dorsal view (11); midbody sternite, ventral view (12); midbody leg, lateral view (13); left gonopod, submesal, subventral, subcaudal and mesal views, respectively (14–17). Scale bars: 0.5 mm (1), 0.1 mm (2–7 & 9), 0.05 mm (10 & 13–13), 0.02 mm (8, 11 & 12).

Fig. 18. Habitus of a male of Myrmecodesmus hastatus (Schubart, 1945), from Saint-Pierre, Martinique, lateral view. Picture by D. VandenSpiegel.

Figs 19 & 20. Right gonopod of a male of Myrmecodesmus hastatus (Schubart, 1945), from Saint-Pierre, Martinique, subventral and subdorsal views, respectively. Scale bar: 0.2 mm. Del. S. Golovatch. Designations: fl – flagellum; sl – solenomere.