Tapinoma pithecorum

Identification
Tapinoma pithecorum is easily separable from other nanitic tropical Tapinoma species – both morphometrically (table I)and by subjective visual inspection. It differs from Tapinoma melanocephalum by a larger postocular index, a shorter scape and 3rd funiculus segment as well as smaller eye length and smaller or absent clypeal excavation. With all measurements in mm, a simple discriminant D(2) = 152.56 × PoOc – 56.444 × SL – 12.5 offers a perfect separation – with 98.5 % of the 65 specimens classified with posterior probabilities of p  > 0.90 (figure 10). D(2) is – 3.095 ± 1.014 [– 5.434, – 0.608] in 51 workers of T. melanocephalum and 2.419 ± 0.945 [0.608, 3.692] in 14 workers of T. pithecorum. According to photo evaluation (table I) it differs from five specimens of Tapinoma indicum by longer scape and funiculus segments, shorter postocular distance, absence of clypeal excavation and the color contrast between mesosoma and gaster. These specimens of T. indicum included the type specimen from Poona (India) (www.antweb.org: CASENT0909774). A synonymy with Tapinoma minutum is also excluded. The type specimen of homogenously colored T. minutum from Sydney (Australia) (www.antweb.org: CASENT0915549) has according to photo evaluation a much longer scape and a much smaller postocular index (table  I) and it shows no color contrast on whole body. The clear separation of the four species is summarized by a principal component analysis (figure 2).

Distribution
Tropical to subtropical species of apparently Orientalic, Indo-Australian and Australasian origin with probably weak tramp species potential and globally much rarer than T. melanocephalum (7 against 76 samples). Outdoor populations are known so far from Oman: Salalah [17.02°N,54.11°E, 9 m], Pakistan: Balakot [34.55°N, 73.35°E, 1070 m], India: Khalgat [22.16°N, 74.45°E, 200 m], Australia: Christmas Island [10.48°S, 105.65°E, 120 m], Fiji: Penang [17.364°S,178.161°E, 36 m] and Malaysia: Cameron Highlands [4.47°N,101.37°E, 1400 m]. Greenhouse populations in the temperate zone are so far only known from Germany: Hannover [52.381°N, 9.771°E, 58 m].

Distribution based on Regional Taxon Lists
Palaearctic Region: Germany.

Nomenclature

 * . Tapinoma pithecorum Seifert, 2022: 39, figs. 4, 6, 7, 9, table 1 (w.) GERMANY.

Type Material

 * Holotype plus two paratype workers labeled “GER: Hannover, Zoo, Affenhaus, Nest in Rindenmulch, leg. STELLMACHER 2002.09.05”; depository SMN Görlitz.
 * Eight paratype workers labeled “INDIAN OCEAN: Christmas Is. I–IV. 1933.”; depositories SDEI Müncheberg (6 paratypes) and SMN Görlitz (2 paratypes). One paratype worker labeled “INDIA: M. P. KHALGHAT, 200 m 1–13–62” and “Collectors: E. S. ROSS, D. Q. CAVAGNARO”; depository NHM Basel. One paratype worker labeled “Balakot 3500', Kagan Valley 24. V.” and “Pakistan 1974, C. BARONI  URBANI”; depository NHM Basel. One paratype worker labeled “Penang 5.III.27.”,  “Dr. EIDMANN  legit”  and  “Nat.Hist.Mus Basel–1972. coll. H. EIDMANN”; depository NHM Basel. One paratype worker labeled  “Oman, Dhofar, Salalah, 18.XI.2017, 9 m, M. R. SHARAF” and “ANTWEB CASENT 0922866”; depositoryCAS San Francisco. One paratype worker labeled“CASENT0095240 ANTC2676”,  “WEST MALAYSIA:Cameron Highlands 500 m below Tana Rana 6.X.–.XXII.2001Traps A & B O.P. CHOO” depository CAS San Francisco.