Aphaenogaster radchenkoi

Aphaenogaster radchenkoi was found in various biotopes such as the zones of chestnut trees and oaks – where Aphaenogaster aktaci was also collected – stream plants, grasses and bushes by using pitfall traps in Izmir-Bozdag. This species has been observed in Turkey and Bulgaria, mostly in open habitats such as grasslands, Quercus coccifera woodlands, chestnut forests and oak forests (Borowiec et al., 2019).

Identification
Kiran et al. (2008) - Aphaenogaster radchenkoi belongs to the pallida group with its small size, mostly smooth and shiny body parts, long and thin hairs. A. radchenkoi differs from the other species of this group by its widely based tooth-like propodeal spines in worker cast and by the long projection on ventral side of the postpetiole in the queen cast. A. radchenkoi shows great similarity with the material described by Agosti and Collingwood (1987a, b) in a species list of Balkan ants as Aphaenogaster as sp1 from Yugoslavia.

Borowiec et al. (2019) - In its original description, this species was only compared with Aphaenogaster subterraneoides (terra typica:  Greece), the most common pallida group member from the Balkans. These authors overlooked another species of the pallida group known from this region: Aphaenogaster finzii (terra typica: Dalmatia). Aphaenogaster finzii is very similar to A. radchenkoi and was recorded from Bosnia and Herzegovina, Greece (Peloponnese), NE Italy, North Macedonia, Montenegro and Serbia (Borowiec 2014). Both species are characterised by the presence of distinct propodeal spines. In A. finzii the spines are thorn-shaped, moderately large, with fairly wide bases and thin apices, while in A. radchenkoi they are claw-shaped, large with a very broad base. In order to clarify if these ants are vicariant species or merely represent geographical variation of a single widely distributed taxon, further research examining more samples from the southern Dinaric area and Western Balkan Peninsula are required.

This species is a member of the A. pallida species group (sensu Schulz, 1994; Borowiec et al., 2019).

Distribution based on Regional Taxon Lists
Palaearctic Region: Bulgaria, Turkey.

Nomenclature

 *  radchenkoi. Aphaenogaster (Attomyrma) radchenkoi Kiran, et al. 2008: 693, fig. 3 (w.q.) TURKEY.

Worker
Head longer than broad (in Aphaenogaster subterraneoides almost as long as broad), broader above the mandibles, widening slightly towards the occiput, generally smooth and shiny, only a few longitudinal striae from mandibles to eyes, frontal area with carina in profile, occipital margin slightly edged, occiput faintly convex, clypeus smooth, anterior margin of clypeus quite wide and shallowly notched, mandibles quite prolonged, longitudinally and roughly striated, masticator border armed with 9–10 gradually decreasing sized teeth from the apical to basal tooth (nevertheless all teeth distinct even basal tooth). Eyes small. Scapus longitudinally striated, with several erect hairs (denser and more erect than in A. subterraneoides) and surpassing the occiput distinctly (longer than in A. subterraneoides), funicular segments 2–6 as wide as long, without antennal club. Mesonotum not raised above the pronotum, promesonotum convex, metanotal groove wide and shallow, propodeum armed with tooth-like, wide based and sharply pointed spines directed outwards in dorsal view, mesopleuron quite distinct, sides of propodeum faintly punctuated, dorsum of propodeum smooth; petiolar peduncle convex ventrally, nodes smooth. Gaster smooth and shiny. Body light yellowish brown, with irregular, sparse, very long hairs.

Queen
Head a bit longer than broad, genal sculpture more distinct than workers, continuing to dorsum of the eyes, frontal area with weak longitudinal striae until median ocellus, anterior margin of clypeus with wide and shallow notch, mandibles shorter than workers, sculpture and teeth as in workers. Dorsum of scutum faintly convex, prescutum weakly depressed, propodeal spines as in workers but ticker, sides of propodeum with a few longitudinal striae, the other parts of mesosoma smooth. Petiole as in workers, postpetiole with long projection ventrally. Gaster smooth and shiny. Body with quite dense and long hairs, gaster hairless except for the joint area of postpetiole and borders of tergites. Colour a bit darker than workers.

Type Material
Holotype – worker: Turkey, Izmir-Bozdag-Golcuk Village 2 km E, (38°18' N, 28°02' E), 1030 m a.s.l., 31.X.2001: 01/1502a (leg. S. Tezcan). Paratypes: 290 workers, 2 dealate queens from same locality as the holotype, 14.IV.2001: 01/1212, 1213a; 28.IV.2001: 01/1215a, 1217a, 1218b; 12.V.2001: 01/1235b, 1236a, 1237b, 1238a, 1239a; 26.V.2001: 01/1260b, 1261a, 1262d, 1263a, 1264a; 09.VI.2001: 01/1284c, 1285b, 1286b, 1287d, 1288c; 01.VII. 2001: 01/1306c; 10.VII.2001: 01/1323e, 1326b; 22.VII.2001: 01/1343d, 1346d, 1347b; 03.VIII.2001: 01/1361f, 1362g, 1363c; 17.VIII.2001: 01/1387c, 1388b, 1389; 30.VIII.2001: 01/1408, 1410d, 1411; 16.IX.2001: 01/1431b, 1432b, 1433b, 1434a, 1435; 29.IX.2001: 01/1454b, 1455a, 1456c, 1457a; 13.X.2001: 01/1476b, 1477c, 1478b, 1479a, 1480a; 31.X.2001: 01/1498b, 1499b, 1500b, 1501, 1502a (leg. S. Tezcan) (TU, LEMT); 41 workers, 1 dealate queen, Turkey, Izmir-Bozdag-Golcuk Village 2 km E, (38°19' N, 28°06' E), 1160 m a.s.l., 14.IV.2001: 01/1210b, 1211; 28.IV.2001: 01/1223b, 1224a; 12.V.2001: 01/1248a; 26.V.2001: 01/1270c, 1272a, 1273a, 1274e; 09.VI.2001: 01/1291d, 1294d, 1295b; 01.VII.2001: 01/1312c, 1318b; 22.VII.2001: 01/1353b; 03.VIII.2001: 01/1372d, 1373d; 17.VIII.2001: 01/1397c; 30.VIII.2001: 01/1418b; 16.IX.2001: 01/1443a, 31.X.2001: 01/1510b (leg. S. Tezcan) (TU); 185 workers, 1 dealate queen, Turkey, Izmir-Bozdag-Golcuk Village 6 km E, (38°18' N, 28°02' E), 1310 m a.s.l., 14.IV.2001: 01/1204, 1206a, 1209a; 28.IV.2001: 01/1226a, 1230b; 12.V.2001: 01/1250c, 1252a, 1253a; 26.V. 2001: 01/1275b, 1276b, 1277a, 1279; 09.VI.2001: 01/1296a, 1297h, 1298d, 1300a; 01.VII.2001: 01/1315d, 1316f, 1317f; 10.VII.2001: 01/1336m; 03.VIII.2001: 01/1375i, 1377i, 1379f; 17.VIII.2001: 01/1400b, 1401b; 30.VIII.2001: 01/1422a; 16.IX.2001: 01/1445b, 1448b; 29.IX.2001: 01/1467b, 1470b; 13.X.2001: 01/1491c, 1492b, 1494; 31.X.2001: 01/1512a, 1513a, 1514, 1516a (leg. S. Tezcan) (TU); 1 worker, Turkey, Izmir-Bozdag 11 km NE, (38°20' N, 28°06' E), 1470 m a.s.l., 30.VIII.2001: 01/1423d (leg. S. Tezcan) (TU); 1 dealate queen, Turkey, Izmir-Bozdag 7 km N, (38◦24' N, 28◦04' E), 1050 m a.s.l., 16.V.2001: 01/1259b (leg. S. Tezcan) (TU).

Etymology
This species is dedicated to Prof. A. G. Radchenko who gave great help to us during our studies.