Aphaenogaster charesi, Salata, Sebastian & Borowiec, Lech, 2016

Salata, Sebastian & Borowiec, Lech, 2016, A new species of the Aphaenogaster cecconii group (Hymenoptera: Formicidae) from Rhodes, Zootaxa 4170 (1), pp. 194-200 : 194-199

Aphaenogaster charesi sp. nov.

Etymology. Named after Chares of Lindos, a Greek sculptor born on the island of Rhodes. Chares constructed the Colossus of Rhodes in 282 BC, one of the Seven Wonders of the Ancient World.

Type material. Holotype (No. LBC-GR01682-HOL) and two paratypes (No. LBC-GR01682- PAR): GREECE, Dodecanese , Rodos | Epta Piges, 99 m | 36,25459 N / 28,11378 E | 4V2015, L. Borowiec || Collection L. Borowiec | Formicidae | LBC-GR01682 (preserved in Department of Biodiversity and Evolutionary Taxonomy, University of Wrocław, Poland) ; two paratypes: Greece, Dodecanese , Rodos | Petaloudes, 240 m | 36,33567 N / 28,06264 E | 8 V 2015, L. Borowiec || Collection L. Borowiec | Formicidae | LBC-GR01747 (preserved in Department of Biodiversity and Evolutionary Taxonomy, University of Wrocław, Poland) ; one paratype: Greece, Dodecanese , Rodos | Petaloudes, 240 m | 36,33567 N / 28,06264 E | 8 V 2015, L. Borowiec || Collection L. Borowiec | Formicidae | LBC-GR01747 (deposited in Natural History Museum, London, United Kingdom) .

Description. Measurements: Workers (n=5): HL: 1.386 ± 0.027 (1.36–1.424); TL: 0.696 ± 0.016 (0.676– 0.719); GL: 0.401 ± 0.016 (0.381–0.417); HW: 0.947 ± 0.03 (0.921–0.978); CW: 0.181 ± 0.01 (0.168–0.201); FLW: 0.313 ± 0.014 (0.302–0.335); SL: 1.875 ± 0.02(1.859–1.913); EL: 0.187 ± 0.01 (0.168–0.201); EW: 0.146 ± 0.008 (0.134–0.156); ML: 1.993 ± 0.08 (1.913–2.098); PSL: 0.26 ± 0.01 (0.246–0.279); SDL: 0.198 ± 0.005 (0.19– 0.201); HTL: 1.667 ± 0.04 (1.609–1.717); PL: 0.582 ± 0.02 (0.559–0.594); PPL: 0.361 ± 0.013 (0.346–0.38); PH: 0.280 ± 0.01 (0.257–0.291); PPH: 0.292 ± 0.01 (0.279–0.304); PNW: 0.649 ± 0.02 (0.623–0.682); DPSB: 0.207 ± 0.013 (0.19–0.223); DPST: 0.239 ± 0.026 (0.221–0.285); PW: 0.211 ± 0.009 (0.198–0.223); PPW: 0.286 ± 0.007 (0.277–0.296); HI: 68.3 ± 0.9 (67.2–69.5); CI: 19.1 ± 1.06 (17.9–20.6); FLI: 57.7 ± 2.3 (55.6–60.3); SI1: 135.3 ± 1.6 (133.3–137.1); SI2: 198.0 ± 4.4 (191.8–203.0); PI1: 204.1 ± 1.9 (202.0–205.8); PI2: 61.5 ± 2.09 (59.7–63.8); PPI1: 123.5 ± 1.7 (121.1–125.9); PPI2: 30.8 ± 0.4 (30.1–31.2); SPI1: 27.4 ± 0.7 (26.7–28.5); SPI2: 131.0 ± 6.2 (122.2–138.9); HTI: 176.0 ± 4.0 (172.0–180.4) MI: 307.3 ± 3.7 (303.8–313.3); PSI: 141.6 ± 4.6 (135.0–147.1); TGI: 173.7 ± 7.4 (165.5–181.5).

Head, thorax and abdomen pale brown, base of gaster with slightly paler basal spot, borders of spot indistinct. Legs uniformly yellowish to yellowish-brown. Antennal scapes yellowish brown, pedicle yellowish ( Figs. 1, 2 ).

Head posterior to eyes gently, regularly convex, without constriction at base, basal margin margined by sharp carina ( Figs. 3 , 4 ). Anterior margin of clypeus shallowly emarginate. Eyes very small, 0.59 times as long as length of tempora. Scapes elongate and slim, 1.94 times as long as width of head, at base 0.5 times as wide as in apex, gradually widened, mostly straight, only apex slightly bent down without preapical constriction. Funicle elongate and thin, 1.42–1.44 times as long as scape, first segment elongate, 2.4 times as long as wide on apex, 1.29 times as long as second segment, length ratio of segments 100:75:88:88:92:92:104:167:167:163:225, apical segments 1. 5 times as wide as basal segments ( Fig. 3 ). Surface of scape finely microreticulate but shiny, covered with short and sparse mostly semierect setae, especially in apical half of scape pubescence distinctly raised from the ground.

Promesonotum 1.87 times as long as wide, pronotum gently convex in profile with very shallow cleft between pronotum and mesonotum. Propodeum elongate, 1.33 times as long as wide, propodeal spines short, needle-like, pointing obliquely upwards ( Fig. 2 ). Petiole elongate with long peduncle, anterior face of node deeply concave, node subangulate in profile. Posterior face straight for first 3/4 of anterior length then shallowly concave. Ventral margin of petiole straight, without spine or distinct angulation ( Fig. 2 ). In dorsal view, petiole with almost parallel sides anterior to petiolar node, then gently widening ( Fig. 5 ). Postpetiole in profile rounded. In dorsal view postpetiole 1.33 times as long as wide, regularly widened from base to apex, apical half with gently rounded sides ( Fig. 5 ).

Mandibles elongate, with outer edges straight, dorsal surface with distinct striation and several setose punctures, shiny, masticatory margin with large apical tooth and 6–7 smaller teeth. Entire surface of clypeus with fine irregular rugae, interspaces microreticulate but shiny. Frontal carinae short, not extending to the line connecting anterior margin of eyes, subparallel, interantennal area deeply impressed, shiny, with only one median, fine carina, frontal triangle with thin longitudinal rugae, microreticulate but shiny. Sides of frons with thin longitudinal rugae, center with distinct microsculpture but shiny. Area between eyes finely microreticulate but appears shiny, microreticulation gradually diffused from front to back but well visible on whole surface, gena and tempora with distinct microreticulation, base of head with diffused microreticulation, surface from slightly dull to shiny. Dorsal surface of pronotum completely microreticulate, sides with fine longitudinal striae. Surface of pronotum shiny, sides more or less shiny, with rows of 4+2+4+2 setae. Entire surface of mesonotum microreticulate and partly microgranulate, sides microgranulate with fine rugae. Dorsum of propodeum microreticulate, in anterior part with fine transverse wrinkles, sides slightly granulate, surface below spiracles with few fine longitudinal rugae but surface of both mesonotum and propodeum appears slightly shiny ( Fig. 2 ). Anterior portion of mesosomal dorsum with 8 setae, posterior portion with only 2 setae, surface of propodeum between spiracles and propodeal spines with a pair of short setae, slightly shorter than spines, in some specimens additional pair of very short setae present halfway between spiracle and base of propodeal spine. Base of petiole and postpetiole microreticulate but without wrinkles, nodes smooth and shiny, covered with several sparse, long setae. Gaster shiny, basal tergite without or with very short longitudinal grooves but with distinct microreticulation ( Fig. 5 ), all tergites with sparse, long, erect setae reaching up to 1.5 times length of propodeal spines.

Legs very long, hind femora 1.03 times as long as thorax, hind tibiae 0.75 times as long as hind femora, hind tarsi 1.15 times as long as hind femora. External surface of femora with short sparse pubescence, in basal half appressed, in apical half semierect. Inner margin with row of sparse, moderately long, setae. Tibiae on sides and posterior surfaces covered with short, semierect pubescence; inner, apical margins with row of slightly longer and semierect setae.

Diagnosis. Aphaenogaster charesi belongs to a subgroup of species that occur in the Dodecanese Archipelago. The other species are A. jolantae from Rhodes and A. olympica from Karpathos. The group is identified by the following characters: the head is elongately oval, gradually narrowed posteriorly, without a narrow neck, and with occiput margined by a low, sharp carina; body is colour dark, from pale brown to almost black. Aphaenogaster charesi is (1) the most microsculptured species, with almost the entire surface of the head and the top of the pronotum distinctly microreticulate; and (2) the palest species, with body pale brown and antennae and legs mostly yellowish. In the other two species only the central part of the head between eyes and the top of the pronotum have diffused microreticulation, and the body is darker, from brown to dark brown and antennae and legs mostly brown. Pubescence on the head, scapes and legs in A. charesi are longer and denser and more raised from the surface than in A. jolantae and A. olympica . Also the pubescence of both the ventral and dorsal part of the head in A. charesi is longer and denser than in the other two species. Aphaenogaster charesi has the smallest eyes in the group (EL 0.168–0.201 vs. 0.218–0.257 in A. jolantae and 0.201–0.257 in A. olympica ) and it differs from A. jolantae by having distinctly longer scapes (SL: 1.859–1.913 vs. 1.457–1.763, SI1: 133.3–137.1 vs. 122.3–130.4) and from A. olympica by having a distinctly longer petiole (PI1: 202.0–205.8 vs. 134.6–169.4). It also differs from both species in the smaller PPI2 index (30.1–31.2 vs. 33.1–43.6 in A. jolantae and 42.2–50.7 in A. olympica ).

In the key to species proposed by Borowiec & Salata (2014) the new species runs to couplet 4 and the key is modified as follow:

4. Head rusty-yellow, frons with brownish triangular patch of diffused borders, thorax, antennae and legs rusty-yellow ( Figs. 3 , 4 , 18 in Borowiec & Salata 2014). SW Turkey...................................... equestris Borowiec & Salata, 2014

- Head, thorax, antennae and legs brown to almost black ( Figs. 5 –6, 9–10, 17, 19 in Borowiec & Salata 2014) or head, thorax and abdomen pale brown and legs uniformly yellowish to yellowish-brown ( Figs. 1–5 here). Dodecanese............... 5.

5. Body pale brown, legs uniformly yellowish to yellowish-brown, paler than thorax ( Figs. 1–2 here). Top of pronotum distinctly microreticulate ( Fig. 2 here). PI1>200 and SL>1.8............................................... charesi sp. nov.

- Body darker, from brown to dark brown, legs and thorax unicoloured ( Figs. 5 –6, 9– 10 in Borowiec & Salata 2014). Top of pronotum with diffused microreticulation (Figs. 6, 10 in Borowiec & Salata 2014). PI1<200 (if bigger then SL<1.8), SL<1.8 (if bigger then PI1<200).................................................................................. 6.

6. Scape shorter (SL: 1.457–1.763, mean 1.686 ± 0.085), head less narrowed posteriorly (HW/NW 1.869–2.119 mean 1.977 ± 0.074). Surface of head with less distinct microsculpture, especially anterior to eyes and around antennal scrobes; occipital part of head with micoreticulation absent or rudimentary (Fig. 24 in Borowiec & Salata 2014). Base of first abdominal tergite without longitudinal grooves or they are very short, without distinct microreticulation between grooves (Fig. 13 in Borowiec & Salata 2014). Body color pale brown ( Figs. 5 , 6 in Borowiec & Salata 2014). Rhodes....... jolantae Borowiec & Salata, 2014 .

- Scape longer (SL: 1.672–1.880, mean 1.752 ± 0.049), head more distinctly narrowed posteriorly (HW/NW 2.132–2.436, mean 2.289 ± 0.082). Surface of head with more distinct microsculpture, especially micoreticulation is well developed anterior to eyes, around antennal scrobes and on occipital part of head (Fig. 25 in Borowiec & Salata 2014). Base of first abdominal tergite with long longitudinal grooves and distinct microreticulation between grooves (Fig. 14 in Borowiec & Salata 2014). Body color dark brown (Figs. 9, 10 in Borowiec & Salata 2014). Karpathos........... olympica Borowiec & Salata, 2014 Distribution. Greece, Dodecanese, Rhodes island.

Biological data. Petaloudes (Valley of the Butterflies) is a mountain valley that is in part a gorge with high rocky walls. It is a well-known tourist attraction inhabited by thousands of the Rhodesian subspecies of the Jersey Tiger Moth ( Euplagia quadripunctaria rhodosensis ). Following the wet season (late May), individuals of this species seeking high humidity cover the entire landscape in the area. Three specimens of A. charesi were collected on a 6 m high rock wall located in a shady spot near the entrance to the valley. This place was extremely humid because of water dripping down the wall from a small source located in the upper part of the valley. The entrance to the nest was probably located in a rock crevice about 2 m from the bottom of the wall. The following ant species were recorded in the same area: Aphaenogaster sporadis Santschi, 1933 , Camponotus aegaeus Emery, 1915 , Camponotus boghossiani Forel, 1911 , Camponotus kiesenwetteri Roger, 1859 , Camponotus lateralis (Olivier 1792) , Camponotus rebeccae Forel, 1913 , Camponotus samius Forel, 1889 , Cataglyphis nodus Brullé, 1833 ), Colobopsis truncatus (Spinola 1808) , Crematogaster ionia Forel, 1911 , Crematogaster schmidti (Mayr, 1853) , Lasius lasioides (Emery, 1869) , Lepisiota melas (Emery, 1915) , Pheidole cf. pallidula , Plagiolepis taurica Santschi, 1920 , Temnothorax antigoni (Forel, 1911) , Temnothorax dessyi (Menozzi, 1936) , Temnothorax cf. exilis, Temnothorax cf. luteus sp1 and Temnothorax cf. luteus sp2.

Epta Piges (Seven Springs) is a site with several springs and a small lake surrounded by woodland. In one place water from the springs flows through a 150 m long tunnel carved in the rocky soil. Two specimens of A. charesi were collected on the humid, cracked wall about 1 m from the entrance to the tunnel. Similar habitat requirements and locations of entries to nests were also observed for three other species of the cecconii group: A.

cecconii on Crete, A. jolantae on Rhodes and A. lykiaensis in Turkey. The following ant species were recorded in the same area: Aphaenogaster festae Emery, 1915 , Aphaenogaster jolantae Borowiec & Salata, 2014 , Aphaenogaster sporadis Santschi, 1933 , Camponotus aegaeus Emery, 1915 , Camponotus baldaccii Emery, 1908 , Camponotus kiesenwetteri Roger, 1859 , Camponotus oertzeni Forel, 1889 , Crematogaster ionia Forel, 1911 , Lasius turcicus Santschi, 1921 , Messor orientalis (Emery, 1898) , Pheidole cf. pallidula , Plagiolepis taurica Santschi, 1920 , Temnothorax cf. luteus sp2, Tetramorium cf. semilaeve and Tetramorium diomedeum Emery, 1908 .

Figures

FIGURE 3. Aphaenogaster charesi sp. nov. (holotype), Worker head and antennae (scale bar = 1 mm).

FIGURES 1 – 2. Aphaenogaster charesi sp. nov. (holotype), 1, Worker dorsal. 2, Worker lateral (scale bar = 2 mm).

FIGURES 4 – 5. Aphaenogaster charesi sp. nov. (holotype), 4, Worker head. 5, Worker petiole, postpetiole and base of gaster (scale bar for 4 = 0.5 mm, for 5 = 0.25 mm).