Temnothorax trabutii ( Forel, 1894 )

Temnothorax trabutii ( Forel, 1894) View in CoL

Figure 7 View FIGURE 7

= Leptothorax lindbergi Santschi, 1931

Investigated type material: 2 syntype worker of trabutii from the MHNG ( Geneva, Switzerland) with the label “ L. angustulus //[worker caste symbol] Nyl// Trabutii //Forel//Tlemcen// L. trabutii Forel // Coll. A. Forel //ANTWEB CASENT0909013 // MGHNG ENTO 0100927 // trabutii ” . 1 syntype worker investigated through AntWeb (CASENT0912958—NHMB, Basel, Switzerland) .

Investigated non-type material: 5 workers with the same collecting data of the type series.

Worker redescription. Body bicolored, with the entirety of the mesosoma and nodes reddish or ferruginous, contrasting with the dark head and gaster. Antennae, legs, and mandibles yellow reddish to dark.

Head subrectangular with rounded margin, clypeus and mandibles rounded. Antennae of 12 segments, antennal clubs of 3 segments. Compound eyes are ovoidal. The mesosoma dorsal profile in lateral view has a stark discontinuity between the metanotum and the propodeum, with the propodeum profile presenting a steep declivity. Propodeal spines very long and erect, often arcuated in dorsal view, and rather straight in lateral view. The petiole has a triangular shape, with a small tooth-like subpetiolar process. The postpetiole has an ordinary ovoidal lateral profile and may appear subhexagonal in dorsal view.

A fine irregular sculpture over the body, with some striae on the dorsum of the mesosoma, often on the head, and largest specimens with a more developed sculpture on all surfaces. Clypeus always with a central carina.

Very sparse, usually erect setae all over the body; dense, fine, and mostly adpressed pilosity on the antennae.

Diagnosis. Compared to the other species, the propodeal dorsum forms a sudden, angulate transition with the rest of the mesosoma and is steeper [PropH2/PropH1: 0.794 ( 0.722, 0.878)]. Spines form a smaller angle with the mesosoma than in T. algiricus and T. atlantis , with no range overlaps [SpANG: 112 (106, 118)]. On most other individual characters, it has average differences but some overlaps with T. algiricus , and no overlaps with T. atlantis . The propodeal spines are longer than in the other species [SPST/CS: 0.458 ( 0.425, 0.485)]. In dorsal view these are divergent at first and then tend to curve inwards, the ratio between their maximum width and the width between their tips being averagely smaller than in the other species [SPWI/SPBA: 1.416 ( 1.227, 1.625)]. The ratio between the spines divergence and their length is smaller than in the other species [SPWI/SPST: 0.723 ( 0.643, 0.812)].

Distribution. Algeria, Morocco.

Taxonomic history. It was described from Algeria ( Tlemcen, Oran) by Forel (1894) as a “race” of T. angustulus with longer spines and different mesosoma Later, Cagniant (1968; 1970) elevated it to species rank but without explaining this decision. Cagniant & Espadaler (1997) considered it a subspecies of T. algiricus , stating that it has a lighter pigmentation and it is the form typical of Quercus ilex forests and semi-arid environments in the Atlas Mountains of Algeria, Morocco, and Tunisia, while T. algiricus algiricus would be typical of coastal environments. Galkowski & Cagniant (2017) reverted its status back to species rank stressing the steep declivity of the propodeal dorsum in profile view and the long spines.

Leptothorax lindbergi Santschi, 1931 was described from Morocco (Amizmiz, Marrakech Safi; 1931) as similar to angustulus and especially to “its race trabutii ” (Santschi 1931). Cagniant & Espadaler (1997) synonymized it under trabutii without providing any explanation.

Comments. This is the most distinctive of the three species we recognize in the complex in terms of qualitative morphology, with our qualitative observations mirroring those of Galkowski & Cagniant (2017). The steep declivity of the propodeal dorsum in profile view is unique in the complex and, alongside the long propodeal spines, is well represented in the drawing of lindbergi by Santschi (1931); although he mentions that spines could be ‘shorter’ than trabutii , we maintain it as a synonym of trabutii as established by Cagniant & Espadaler (1997).

We found a large dark-colored T. algiricus worker as the top specimen of a T. trabutii syntypes pin from the NHMG; however, despite being in the same pin with type T. trabutii specimens, it was the only worker glued on the side of the mesosoma instead of on the coxae, as all the T. trabutii specimens of that and the other pins were (and as myrmecologists normally prefer). This anomaly suggests that this very different specimen may have been added to the pin by mistake and not by Forel as a part of the original type series.