Crematogaster ramamy Blaimer, 2013

Blaimer, Bonnie B. & Fisher, Brian L., 2013, Taxonomy of the Crematogaster degeeri-species-assemblage in the Malagasy region (Hymenoptera: Formicidae), European Journal of Taxonomy 51, pp. 1-64 : 48-51

Crematogaster ramamy Blaimer sp. nov.

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Fig. 19

Diagnosis

Within the C. degeeri -assemblage, this species is uniquely recognized by a transverse impression ( Fig. 5E ) across the propodeum, although this character can be faint and difficult to see. Additional useful distinguishing characters are abundant erect pilosity on the promesonotum (>eight setae) and carinulate or costulate sculpture on the pronotum. In its distribution range C. ramamy sp. nov. can only be confused with C. dentata stat. nov., however, the species has longer propodeal spines than the latter ( C. dentata stat. nov.: SPI 0.01 - 0.10; C. ramamy sp. nov.: SPI 0.07 - 0.12), and costulate sculpture on the pronotum (aciculate - reticulate in C. dentata stat. nov.). Mean barcode divergences between C. ramamy sp. nov. and other species within the C. degeeri -assemblage are 12.7 - 18.7 %, except with regard to C degeeri , where this is only 4.7% ( Table 3 ). In our analyses, C. ramamy sp. nov. renders C. degeeri paraphyletic (see comments in description of C. degeeri ).

Etymology

Crematogaster ramamy sp. nov. is named after a Malagasy friend and research assistant, Maminiaina “Mamy” Rajaonarivo, in appreciation of support over several years. The name is treated as a noun in apposition.

Type specimens

Holotype

Worker: pinned, CASENT0317780 , BLF20074, on low vegetation [imaged on AntWeb]; original locality label: MADG’R: Mahajanga: Antanambezo , 20 m - 14.87893º S, 47.97712º E, 20 Apr. 2008, mangrove, Fisher et al., BLF#; deposited at CASC.

Paratypes

4 workers, pinned, same collection and locality data as holotype. #1: CASENT0317781 , deposited at SAMC. #2: CASENT0317782 , deposited at MHNG. #3: CASENT0317783 , deposited at MCZC. #4: CASENT0317784 , deposited at UCDC.

Type locality

MADAGASCAR: Mahajanga: Antanambezo : -14.87893, 47.97712, 20 m, mangrove.

Other material examined

( BBBC, CASC, PSWC): refer to Supplementary Material 1.

Worker

Measurements

(n = 16) [holotype] HW 0.75 - 1.04 [0.95]; HL 0.71 - 0.94 [0.90]; EL 0.16 - 0.22 [0.17]; SL 0.62 - 0.82 [0.72]; WL 0.86 - 1.12 [1.03]; SPL 0.06 - 0.12 [0.09]; PTH 0.12 - 0.22 [0.18]; PTL 0.22 - 0.31 [0.27]; PTW 0.22 - 0.33 [0.28]; PPL 0.13 - 0.19 [0.17]; PPW 0.20 - 0.33 [0.27]; LHT 0.65 - 0.82 [0.73]; CI 1.05 - 1.13 [1.05]; OI 0.19 - 0.24 [0.19]; SI 0.75 - 0.87 [0.80]; SPI 0.07 - 0.12 [0.09]; PTHI 0.55 - 0.76 [0.66]; PTWI 0.95 - 1.14 [1.04]; PPI 1.36 - 1.80 [1.58]; LBI 1.27 - 1.41 [1.40].

Description

( Fig. 19A , C-D) Small to medium size (HW 0.75 - 1.04, WL 0.86 - 1.12).

Masticatory margin of mandibles with four teeth; head shape quadrate, as long or slightly longer than wide (CI 1.05 - 1.13); posterior margin of head in full-face view laterally rounded or subangular; occipital carinae usually distinct; antennal scapes reaching or surpassing head margin; midline of eyes situated slightly above midline of head in full-face view; eyes moderately large (OI 0.19 - 0.24) and protruding.

Pronotum laterally angular; promesonotal suture indistinct; mesonotum more or less forming one plane with pronotum, but often the two separated by distinct variation in sculpture (see below); mesonotum usually without posterior face; laterally mesonotum angular to carinate, not distinctly set off from propodeum; metanotal groove shallow, laterally constricted; propodeal spines short, spiniform (SPI 0.07 - 0.12), usually curved downwards; dorsal face of propodeum short but distinct; posterior face of propodeum gently sloping, often with a transverse groove; petiole in dorsal view oval and fairly slender, dorsolaterally rounded, without posterolateral tubercules or denticles; subpetiolar process variable, usually a small dent; postpetiole distinctly bilobed, with a narrow median impression; subpostpetiolar process absent.

Head sculpture aciculate to reticulate; pronotum usually dorsally carinulate and contrasting abruptly with a shiny to aciculate mesonotum; mesopleuron areolate, metapleuron mostly carinulate; dorsal face of propodeum carinulate or reticulate; otherwise sculpture reticulate; face usually with six to ten erect, longer setae, and regular appressed to decumbent pubescence; erect pilosity on promesonotum usually abundant, with> eight long setae; otherwise promesonotum dorsally with regular appressed to subdecumbent pubescence; petiole and postpetiole usually with a pair of short erect, setae posterolaterally, and shorter suberect, decumbent or appressed pubescence; abdominal tergites and sternites four to seven usually with abundant, short, erect pilosity, and abundant appressed to decumbent pubescence throughout. Color reddish brown to dark brown.

Queen and male

Queens and males of this species are unknown.

Distribution and biology

MADAGASCAR. Crematogaster ramamy sp. nov. is a species found at low elevations in dry forest, savannah and sometimes mangrove habitats in western and northwestern Madagascar ( Fig. 19B ). The species further has a disjunct, isolated population at higher altitude in the transitional dry forest of RS Ambohitantely (1410 m). Crematogaster ramamy sp. nov. usually co-occurs with C. dentata stat. nov., C. maina sp. nov. and C. lobata , and at some locations also with C. tricolor stat. rev., C. mafybe sp. nov. and C. sewellii . Generally it has been collected nesting arboreally in dead twigs above the ground, and is attracted to arboreal fish baits as strongly during the day as at night.

Comments

This species has close affinities with C. degeeri , and does not appear to be reciprocally monophyletic according to our analysis ( Fig. 1 ). Crematogaster ramamy sp. nov. is however sufficiently distinguishable morphologically from C. degeeri , and more importantly seems quite distinct in its distribution and ecological adaptation (dry forest in contrast to montane grassland and woodland for C. degeeri ).

Figures

Fig. 19. Crematogaster ramamy sp. nov., worker and distribution. A, C-D. Worker (CASENT0317780). A. Full-face. C. Profile. D. Dorsal. B. Species distribution.

Fig. 5. Key to the species of the C. degeeri-assemblage (part II). A. Pronotum with sharp lateral margins [C. malahelo sp. nov., CASENT0317768]. B. Pronotum lacking sharp lateral margin [C. alafara sp. nov., CASENT0492837]. C. Mesonotum with posterolateral denticles [C. degeeri Forel, 1886, CASENT0071423]. D. Mesonotum without distinct posterolateral denticles [C. ramamy sp. nov., CASENT0317764]. E. Propodeum with distinct short dorsal face and transverse impression, sculpture carinulate [C. ramamy sp. nov., CASENT0317764]. F. Propodeum lacking distinct dorsal face and transverse impression, sculpture rugulose [C. dentata Dalla Torre, 1893 stat. nov., CASENT0138289].

Fig. 1. Mitochondrial phylogeny of species in the Crematogaster degeeri-assemblage. Results of Bayesian inference based on 592 bp of COI, summarized as a consensus tree in MrBayes. Support values in black represent posterior probabilities (pp), those in blue ML (Maximum Likelihood) bootstrap values>70, and those in red ML bootstrap values<70. Values pp <0.96 are not shown; nodes not present in the ML analysis are represented by a dash instead of a bootstrap value. The scale bar shows nucleotide changes per base pair. Long branches subtending the outgroup taxa C. madecassa Emery, 1895, C. ranavalonae Forel, 1887 and C. hova-complex have been shortened. Appended numbers on taxon labels represent CASENT#’s of respective voucher specimens.