Myrmica hellenica

A soil nesting species that can often be found in open habitats.

Identification
M. hellenica belongs to the rugulosa-complex of the scabrinodis species group (see Radchenko and Elmes 2004) and might be confused with Myrmica specioides and Myrmica constricta. It differs from M. specioides by its less curved frontal carinae and wider frons. The Caucasian and Turkish populations of this species have mean FI 0.43 and FLI 1.15, and the Crimean populations have mean FI 0.41 and FLI 1.20, while mean FI in M. specioides is 0.38, and FLI 1.32. Although the scape of M. hellenica is clearly angled at its base, it has at most a narrow longitudinal ridge on the bend rather than the distinct lobe of M. specioides.

M. hellenica separates from M. constricta first by the sculpture of the head, its frons is completely longitudinally rugulose whereas the upper (rear) third of that of M. constricta has distinct reticulation, and secondly its propodeal spines are distinctly longer than those of M. constricta. Queens of M. hellenica are distinctly larger than those of M. constricta (and M. rugulosa), which are quite small (HW > 1 mm vs. HW < 1 mm respectively). Males of M. constricta well differ from those of M. hellenica by much shorter standing hairs on the mid and hind tibiae and tarsi.

Distribution based on Regional Taxon Lists
Palaearctic Region: Armenia, Austria, Bulgaria, Croatia, Finland, Georgia, Germany, Greece, Iran, Italy, Montenegro, Poland, Romania, Serbia, Slovenia, Switzerland, Ukraine.

Biology
Radchenko and Elmes (2010) - The following is a combination of our (Radchenko and Elmes 2004) observations for M. rugulososcabrinodis in Turkey and those of Seifert et al. (2009) for M. hellenica. Over its geographical distribution it occupies a very wide range of both anthropogenic and semi-natural biotopes but we found it to be most abundant in hay meadows on the north facing slopes (higher rainfall areas) at 400-1700 m a.s.l. in the northeast Turkish mountains. Here it builds nests in soil, often under stones and colonies have one to several queens and contain several hundred workers. Seifert et al. (2009) write that “It is in its abundance and competitive power the absolutely dominant Myrmica species at the Caucasian coast of the Black Sea at altitudes below 600 m a.s.l.”. In the Caucasus it can be found in sunny positions as high as 1600 m a.s.l. and in Turkey Seifert found it at 2300 m a.s.l., which accords with our observations.

Seifert et al. (2009) use climate data to suggest that the species is ecologically very plastic with air temperatures at recorded sites for M. hellenica ranging from 7°C in May to 24°C in August with a huge amplitude around the mean (TAS 17.7 ± 4.0°C) in contrast to the related M. constricta (TAS 16.3 ± 1.8°C; 14-23°C from May - August); they suggest that something other than low winter and summer temperatures limit the northern expansion of M. hellenica. We suggest that probably M. hellenica has adapted behaviourally and physiologically to make use of southern mountain habitats that are cold in winter and hot in summer with a relatively short "growing season" (see Chapter 1.3 for an overview of such differences).

In Turkey we found that the microhabitats used by M. hellenica are usually quite cool in spring, either they are wet (sometimes even flooded) or they live under the long grass in hay meadows. In high summer theses microhabitats become typically xerothermous, the wet meadows are grazed and dry out, the hay is cut and the grass becomes dormant. It seems to us that were it not for the cool shady conditions in spring the sites where M. hellenica is abundant would be dominated by ants of other genera better adapted to withstand the high summer soil temperatures - Tapinoma Foerster, Tetramorium, Lasius and Formica species, the cool spring conditions prevent such species from successfully completing their annual life cycle. Therefore the challenge for M. hellenica is to complete its life cycle before the habitat becomes too hot and dry for normal foraging. In Turkish populations sexuals are in the nest by early August and we suspected that nuptial flights usually take place by mid-August. Colonies then more or less aestivate foraging for very short periods at the start and end of daylight.

We suggest that M. hellenica might have a high metabolism more similar to that of northern species (e.g. M. ruginodis, see Chapter 1.3.5) that enables it to rear larvae in the cool spring conditions when there could be abundant insect prey. On the other hand, Seifert et al.'s (2009) climatic data for the related M. constricta indicates that a lower metabolism associated with more southern species (e.g. M. sabuleti) might be more appropriate to its habitat. If the ants can achieve significantly longer foraging time in spring and autumn they tend to "grow brood" more slowly than species adapted to short growing seasons. So it might be that M. hellenica originally derived from M. constricta in order to exploit southern mountain habitats, then due to anthropogenic influences, such as the creation of hay meadows, M. hellenica has become more common and widespread than it would be without man's influence. It would be interesting to test this idea by a comparative physiological and behavioural study of the two species.

Nomenclature

 *  hellenica. Myrmica rugulosa var. hellenica Finzi, 1926: 93 (w.q.m.) GREECE. [First available use of Myrmica scabrinodis r. rugulosa var. hellenica Forel, 1913d: 431; unavailable name.] Finzi, 1926: 93 (m.). Raised to species: Agosti & Collingwood, 1987b: 267; Seifert, 1988b: 13. Senior synonym of caucasica, rugulososcabrinodis, striata: Seifert, et al. 2009: 68. See also: Radchenko & Elmes, 2010: 145.
 * rugulososcabrinodis. Myrmica (Myrmica) rugulosa var. rugulososcabrinodis Karavaiev, 1929b: 205, fig. 1 (w.m.) GEORGIA, ARMENIA. Junior synonym of bessarabica: Dlussky, Soyunov & Zabelin, 1990: 182; Atanassov & Dlussky, 1992: 93. Revived from synonymy and senior synonym of caucasica: Radchenko & Elmes, 2004: 231. Junior synonym of hellenica: Seifert, et al. 2009: 68.
 * caucasica. Myrmica rugulosa subsp. caucasica Arnol'di, 1934: 165, figs. 17-20 (w.m.) CAUCASUS. [Unnecessary replacement name for rugulososcabrinodis Karavaiev.] Seifert, 1988b: 19 (q.). Raised to species: Seifert, 1988b: 19. Junior synonym of bessarabica: Dlussky, Soyunov & Zabelin, 1990: 182; Atanassov & Dlussky, 1992: 93; of rugulososcabrinodis: Radchenko & Elmes, 2004: 231; of hellenica: Seifert, et al. 2009: 68.

Etymology
Radchenko and Elmes (2010) - derived from the Greek word Hellenica, which referred to writings on Greece, but now means anything Greek, to indicate that it was described from Greece.