Crematogaster claudiae

A member of a group of Crematogaster species associated with Macaranga plants in Sumatra, Borneo, and Peninsula Malaysia.

Identification
Feldhaar et al. (2016) - A member of the Crematogaster captiosa subgroup within the Crematogaster borneensis group. Worker: Propodeal spines usually absent, when present very short, petiole distinctly wider than postpetiole (PI > 1.15), Legs and scapi short, RLEG < 0.69 and SI < 0.65. Queen: EL 0.45 - 0.5 mm (REL 0.36-0.39), OD1 > OW, PI > 1.0, ROD between 0.13-0.17.

Distribution
Sabah, Borneo.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Malaysia.

Biology
Feldhaar et al. (2016) - Crematogaster claudiae is endemic to Borneo, possibly even to Sabah (see below). The species had mainly been found on two different species of the section Pachystemon (Macaranga glandibracteolata and Macaranga indistincta). We have evidence that this species may hybridize (at least locally) with Crematogaster captiosa (in Poring Hot Spring) and presumably fertile offspring (queens) can be produced by rare hybrid queens (Feldhaar et al., 2008; Feldhaar et al., 2010).

In comparison to all other species of the captiosa-subgroup the queens have relatively small compound eyes (smaller than 0.5 mm) and an earlier onset of reproduction, when colonies comprise approximately 500 workers. Unlike the queens of other captiosa-subgroup species, queens of C. claudiae only colonize saplings. Two samples contained in the phylogeny based on mitochondrial DNA (Feldhaar et al., 2010) collected in Sarawak cluster with samples of C. claudiae from Sabah (see above in distribution and biology of Crematogaster hullettii). Thus, we can currently not exclude that C. claudiae has a wider distributional range than Sabah only.

Nomenclature

 *  claudiae. Crematogaster claudiae Feldhaar, Maschwitz & Fiala, 2016: 670, figs 3.4, S1.7A-D (w.q.) MALAYSIA.

Worker
Paratype. CI 0.97, DPPW 0.18, DPW 0.21, EL 0.1, HL 0.72, HW 0.7, LHT 0.53, (LPS only nodiform elevation; distance from anterior to posterior margin of propodeal spiracle 0.068), MTW 0.42, PI 1.13, REL 0.16, RLEG 0,61, SI 0.64, SL 0.45, (TL 3.0), WL 0.87.

(n=8) CI 0.96-1.0, DPPW 0.16-0.19, DPW 0.19-0.23, EL 0.1- 0.14, HL 0.65-0.75, HW 0.61-0.72, LHT 0.46-0.56, LPS 0.053- 0.094 (in part only nodiform elevation above propodeal spiracle), MTW 0.39-0.45, PI 1.13-1.29, REL 0.16-0.19, RLEG 0.58-0.69, SI 0.61-0.65, SL 0.39-0.45, (TL 2.5-3.4), WL 0.7-0.94.

Colour uniformly medium brown. Workers monomorphic in size. Total body length of workers from 2.5 to 3.4 mm. Head, gaster and alitrunk shiny with smooth surface. All body parts bear appressed pubescent hairs. Long flexuous setae present on head, gaster and abdomen: on head especially in frons, on gaster more on the posterior margins of tergites and sternites. Only few setae on alitrunk and one pair each on petiole and postpetiole.

Head subquadratic but slightly elongated, always being longer than wide or as long as wide (CI ≤1.0) and only slightly convex on sides. Anterior clypeal margin slightly convex and with a row of long erect setae projecting anteriorly. Occipital margin slightly convexly rounded, occipital lobes rounded. Mandibles relatively short and with four denticles, capable of closing tightly against the clypeus. Denticles increasing continuously in size from posterior (close to clypeus) to anterior. Surface of mandibles smooth, covered with short pubescent hairs.

Antennae relatively short in comparison to head width (SI 0.61-0.65; mean 0.63) and covered in short pubescent hair. Terminal three funicular segments form a club. Compound eyes elliptically shaped and not protruding over margin of head in full-face view. Pronotum and mesonotum form a convex dome in profile. Anterodorsal surface of pronotum sloping downwards less steep than posterodorsal surface of mesonotum. Metanotal groove slightly notched. Promesonotal suture visible and dorsally slightly notched.

Propodeal spines very short or nearly absent, but then dorsally of the propodeal spiracle nodiform elevation. When short spines are present, the tip of the spines protrudes only slightly over posterior margin of the propodeal spiracle. Slope of the posterior face of the propodeum similar to posterior slope of mesonotum and approximately 45°.

In dorsal view petiole and postpetiole round in shape. Petiole always distinctly wider than the postpetiole (PI: 1.13-1.29). In lateral view the anterior face of the petiolar node flattened and sloping downwards anteriorly and petiole longer than postpetiole. Dorsal surface of the postpetiolar node in profile rounded, lateral nodes visible. Subpetiolar process usually absent.

Queen
Holotype. CI 1.0, DPPW 0.44, DPW 0.46, EL 0.46, HL 1.28, HW 1.28, LHT 0.96, MTW 1.07, OD1 0.18, OD2 0.06, OW 0.15, PI 1.05, REL 0.36, RLEG 0.43, ROD 0.139, ROD2 0.049, SI 0.52, SL 0.66, (TL 6.8), WL 2.24.

(n=11) CI 1.0-1.05, DPPW 0.41-0.48, DPW 0.44-0.52, EL 0.45-0.5, HL 1.23-1.29, HW 1.23-1.30, LHT 0.90-0.96, MTW 0.99-1.21, OD1 0.17-0.22, OD2 0.06-0.09, OW 0.13- 0.16, PI 0.97-1.1, REL 0.36-0.39, RLEG 0.42-0.49, ROD 0.131-0.167, ROD2 0.049-0.071, SI 0.51-0.52, SL 0.64-0.67, (TL 6.5-7.2), WL 2.13-2.31 Queens medium in size, from 6.5 to 7.2 mm in total body length and uniformly medium brown in colour. Surface of head and gaster smooth and shiny alitrunk slightly less shiny and faintly shagreened. All body parts bear appressed pubescent hairs. Long flexuous setae present on head gaster and abdomen: on head especially in frons, on gaster more on the posterior margins of tergites and sternites. A row of long erect setae pointing anterior present on the clypeus. Mandibles relatively short, capable of closing tightly against the clypeus.

Head approximately as wide as long (CI: 0.99-1.05; mean 1.01). Sides of the head straight and head narrowing slightly from posterior towards clypeus. Occipital margin of the head slightly concave. Occipital lobes strongly rounded. Anterior clypeal margin slightly convex. Terminal four segments of funiculus continuously increasing in size forming an indistinct antennal club. Antennal scrobes strongly developed, with an acute and marked dorsal margin; the frontal carinae short.

Compound eyes oval-shaped from lateral view and convex from dorsal view, with the margin of the compound eyes protruding from the sides of the head (see Fig 3.4; Fig S1.7A and S1.7B). Diameter of the compound eyes spans slightly over one third of HL (REL 0.36-0.39). Maximum diameter of compound eyes ranges from 0.45 to 0.5 mm. Ocelli relatively small in diameter. Diameter of median ocellus (OW) always smaller than distance between lateral ocelli (OD1).

Mesoscutum convexly rounded anterodorsally. Mesoscutellum nearly in horizontal plane in lateral view. Propodeum flattened dorsally and then drops off at an angle of approximately 45° posterior of the propodeal spiracle. Mesoscutum relatively short, stretching out over less than half of the alitrunk in lateral view. In dorsal view, the posterior margin of the propodeum slightly convexly rounded and the mesonotum broadly triangular. Propodeum not armed with spines.

Node of petiole and postpetiole in dorsal view rounded. Petiole as wide as or wider than the postpetiole (mean PI: 1.05). In lateral view petiole anterodorsally flattened and sloping downwards and slightly longer than the postpetiole. Postpetiole round in dorsal and lateral view without distinct nodes.

Type Material
Holotype. Queen (to be deposited in, provisional specimen number HF00-Mind.10-Q) (H. Feldhaar) on 18.10.2000 in Poring Hot Spring from Macaranga indistincta. Paratype. Worker collected from the same colony (to be deposited in SMNK, provisional specimen number HF00-Mind.10-W).

Determination Clarifications
In former publications by our group this species was referred to as Crematogaster msp. 10 (Feldhaar et al., 2008; Feldhaar et al., 2010).

References based on Global Ant Biodiversity Informatics

 * Feldhaar H., U. Maschwitz, and B. Fiala. 2016. Taxonomic revisions of the obligate plant-ants of the genus Crematogaster Lund (Hymenoptera: Formicidae: Myrmicinae), associated with Macaranga Thouars (Euphorbiaceae) on Borneo and the Malay Peninsula. Sociobiology 63(1): 651-681.