Meranoplus cryptomys Boudinot & Fisher

Boudinot, B. E. & B. L. Fisher, 2013, A taxonomic revision of the Meranoplus F. Smith of Madagascar (Hymenoptera: Formicidae: Myrmicinae) with keys to species and diagnosis of the males., Zootaxa 3635 (4), pp. 301-339 : 316-320

Meranoplus cryptomys Boudinot & Fisher sp. n.

(Figs. 21, 26, 27, 33-38, 63)

Holotype worker, MADAGASCAR: Toliara, P.N. Tsimanampetsotsa, Bemanateza 23.0 km 131° SE Behaloka, 23°00' S, 43°53' E, 90 m, malaise, spiny forest/thicket, collection code BLF6257, 22-26Mar2002 (B.L. Fisher et al.) (CASC: CASENT0440939).

Paratype worker: with same data as holotype, except collected via pitfall (CASC: CASENT0077998). Paratype gyne, MADAGASCAR: Tuléar, P.N. Andohehala, 24°49.85' S, 46°32.17' E, 60 m, spiny forest, collection code Mg-21-35, 15-26Oct2003 ( Rin’Ha, M.E. Irwin) (CASC: CASENT0132374).

Description

Worker (types). HL 0.95-0.99, HW 0.91, HLA 0.30-0.31, CW 0.35-0.37, CDD 0.13, SL 0.61-0.65, EL 0.22-0.23, EW 0.15-0.16, PML 0.71-0.73, PWA 0.91-0.96, PWP 0.64-0.67, SPL 0.12-0.17, WL 0.98-1.01, PTL 0.22, PTH 0.46-0.50, PPL 0.21-0.24, PPH 0.40-0.41, ATW 1.32-1.39, ATL 1.36-1.41, CI 92.2-95.0, SI 67.8-70.9, OMI 74.1-76.2, CDI 35.0-37.9, SEI 275-276, PMI 128.2-130.8, PWI 70.3-70.2, CS 0.9-1.0, EYE 40.8-41.2 (2 measured).

Bicolored; head, mesosoma, petiole and postpetiole orange; abdominal segments IV–VII dark brown.

Head longer than broad (CI 92-95). Basal area of mandibles smooth, grading into striations apically. Face rugose to areolate; anterior region of the nuchal carina areolate. Sculpture above and behind eyes areolate; sculpture beneath the eyes rugose. Scrobal carina well-developed, strong. Anterior margin of clypeus with bilobed lamina; lobes relatively wideset (CDI 35-38). Middle portion of clypeus costate laterally. Eyes large (EYE> 40). Maximum eye length about ¾ the length of the malar area (OMI 74-76). Face with dense suberect to erect short setae and somewhat more dilute erect long setae.

Promesonotal shield broader than long (PMI 128-131); pronotal shield wider anteriorly than posteriorly (PWI 70). Dorsum of promesonotum with areolate sculpture which weakens in posterior half. Setae on promesonotal shield erect to subdecumbent, of various lengths. Lateral face of pronotum with a few haphazardly oriented fine costae . Lateral face of mesonotum (beneath overhanging shield) with weak foveate sculpture. Incomplete costae present on meso- and metapleurae. Metapleural lobes well-developed. Propodeal spines narrow and curved upwards. Dorsomedian carina of propodeal spine curves medially across the posterior face of the propodeum. Posterior face of propodeum with costae crossing over the strongly arched promesonotal-propodeal suture.

Petiole cuneate in lateral view; without pedicel. Anteroventral process of petiole fingerlike, separated from the sternite and projecting anteroventrally. Postpetiole subrectangular in lateral view, taller than broad (PPI 52-57). Sub-postpetiolar process well-developed, sloping evenly towards posterior margin of post-petiolar sternum. Dorsal face of postpetiole rugose; lateral face weakly costate; posterior face weakly rugose. Fourth abdominal tergum (ATIV) large (ATW/WL> 1.34; ATL/WL> 1.38). ATIV shining; weakly areolate between strong stellate setiferous punctures. ATIV setae of mixed lengths; short setae suberect; long setae erect; relatively long setae decreasing in length from base of abdominal tergum IV.

Queen (paratype in parentheses). HL 1.01-1.12 (1.01), HW 1.00-1.07 (1.00), HLA 0.31-0.32 (0.31), CW 0.38-0.41 (0.38), CDD 0.10-0.13 (0.11), SL 0.70-0.74 (0.74), EL 0.26-0.29 (0.26), EW 0.21 (0.21), SPL 0.19-0.23 (0.23), WL 1.39-1.49 (1.43), PTL 0.27-0.31 (0.30), PTH 0.47-0.49 (0.47), PPL 0.24-0.30 (0.25), PPH 0.47-0.52 (0.49), ATW 1.47-1.58 (1.47), ATL 1.68-1.92 (1.77), CI 92.1-97.6 (96.1), SI 66.5-70.3 (70.3), OMI 72.6-78.5 (73.1), CDI 25.9-32.8 (29.4), SEI 253-283 (283), CS 1.1 (1.1), EYE 43.3-45.3 (43.9) (6 measured).

Bicolored; head, mesosoma, petiole, and postpetiole orange; abdominal segments IV–VII burnt orange laterally and ventrally; dark brown dorsally.

Head longer than broad (CI 94-99). Mandibles striate. Face with rugose sculpture grading into areolate sculpture posterior to the ocelli. Sculpture above eyes areolate; behind and beneath rugose. Scrobal carina well-developed; broadest at about ¼ along its length. Anterior margin of clypeus with frontal lamina produced into two wideset lobes (CDI 40-43). Middle portion of clypeus costate; costae in lateral thirds of this area strong; costae in middle third of this area weak. Eyes large (EYE 44-46). Maximum eye length greater than 4/5 the length of the malar area (OMI 82-92). Scapes short (SI 62-60). Face with erect setae; shorter setae more numerous than longer setae.

Mesosoma longer than tall. Anterolateral corners of pronotum produced into well-developed denticles; dorsolateral margin of pronotum somewhat indistinct. Mesosomal dorsum areolate to rugose. Dorsum of mesosoma with setae of various lengths; longest setae on mesoscutellum. Lateral face of pronotum areolate in ventral half grading into rugosity. Katepisternum costate with smooth areas in the dorsal half. Anterior portion of anepisternum shining; posterior portion rugose. Metapleuron and lateral face of propodeum costate, in addition to the usual costae across the metapleural gland bulla. Propodeal spines small and triangular (SPL 0.12-0.15). Procoxae without distinct anterolateral shoulders; weakly striate. Wings as in male diagnosis.

Petiole cuneate; anterior face longer than posterior face. Postpetiole nodiform, rounded posterodorsally. Sternal process of postpetiole well-developed. Dorsal face of postpetiole areolate to rugose; lateral faces strongly rugose-costate; posterior face weakly rugose-costate. Fourth abdominal tergum (ATIV) with sides in dorsal view parallel to sub-parallel. ATIV long (ATL/WL 1.21-1.38). The sculpture of ATIV is rough around the base of the tergum, with somewhat areolate sculpture in this area; posterior to this area, the sculpture is smooth and shining with weak-to-fine areolation between the stellate setiferous punctures. The setae of ATIV are very short: short setae are most numerous, and shorter than the propodeal spines.

Male. unknown.

Diagnosis

Worker. The fingerlike subpetiolar process uniquely identifies this species in the Malagasy fauna. Additional characters include: head almost as broad as long (CI 92-95); eyes large (OMI> 65, EYE mean 41); scapes less than three times as long as eyes (SEI <280); posterolateral denticles of promesonotal shield set wide (PWI> 68); ATIV large (ATW/HW> 1.40, ATL/HL> 1.40).

Gyne. The long malar area (OMI 82-92) and short scapes (SI 60-62) uniquely identify this species in the Malagasy fauna. Supporting diagnostic characters include: bicolored orange and brown; strong scrobal carinae; comparatively small (WL 1.4-1.6); wideset clypeal denticles (CDI 41-43); short, triangular propodeal spines (SPL 0.12-0.15); relatively few (<30) long suberect setae on fourth abdominal tergum.

Comments

Despite the infrequent collection of this presumably rare species, M. cryptomys has a relatively broad range within the spiny forest/thickets and savanna woodland habitats of Madagascar. Workers of Meranoplus cryptomys are only known from two individuals collected at Tsimanampetsotsa, while gynes have been collected at the Isalo and Andohahela National Parks and the Beza Mahafaly Reserve. Neither hand-collected workers nor nests have been collected; all known individuals are from Malaise or pitfall traps. Although two female castes have not been collected together, they share characteristics unique to the Malagasy Meranoplus and indicate they belong to the same specie: comparatively short scapes, widely set clypeal denticles, high oculomandibular indices (OMI), characters of sculpturation, and the striking orange bicoloration. The strong orange and black bicolored coloration of M. cryptomys is notable for its similarity to that of M. mayri . These two species overlap in range across the south and southeast of Madagascar, from Andohahela to Isalo.

Etymology

The relatively widespread range and infrequent collection of this new species, coupled with its large eyes and relatively short pilosity, suggests the image of a mouse hiding from cats or collectors. The specific epithet is a noun in apposition and thus invariant.

Additional material examined

MADAGASCAR: Tuléar, Beza Mahafaly Reserve, Parcelle I, 23°41.19' S, 44°35.46' E, 165 m, malaise, tropical dry forest, coll’n code Ma-14A-01, 15 Oct– 10Nov2001 (M.E. Irwin et al.); Tuléar, P.N. Andohehala, 24°49.85' S, 46°32.17' E, 60 m, spiny forest, coll’n code Mg-21-23, 22-29Jun2003 ( Rin’Ha, M.E. Irwin); Fianarantsoa, Ampotoampoto, P.N. Isalo, 22.62944° S, 45.18900° E, 91 m, savanna woodland, coll’n code ARA0120-18, 27-28Feb2010 (A. Ravelomanana).