Polistes nimpha (Christ)

Schmid-Egger, Christian, Achterberg, Kees van, Neumeyer, Rainer, Jerome Moriniere, & Schmidt, Stefan, 2017, Revision of the West Palaearctic Polistes Latreille, with the descriptions of two species an integrative approach using morphology and DNA barcodes (Hymenoptera, Vespidae), ZooKeys 713, pp. 53-112 : 96

Polistes nimpha (Christ) Figs 20 23

Vespa nimpha Christ, 1791, Naturgesch. Insekt.: 232. Types (female, male) lost, type locality: Kronberg, Taunus (Germany).

Vespa diadema Latreille, 1802, Ann. Mus. Hist. Nat. 1: 292, nec Christ, 1791. Type (female) lost, type locality: surroundings of Paris (France).

Polistes opinabilis Kohl, 1898, Ann. Naturh. Hofmus., Wien 13: 90 + Taf. III. Lectotype male (NHMW, examined by RN & CvA) designated by Bluthgen (1943: 127), type locality: Frain [= Vranov], Moravia (Czech Republic).

Polistes nimpha var. Moltonii Guiglia, 1944, Atti d. Soc. Italiana di Sc. Nate del Museo Civico di Storia Naturale in Milano 83: 166. Holotype female (MSNM, not examined), type locality: Spotorno, Liguria (Italy).

Polistes nimpha irakensis Gusenleitner, 1976: 119. Holotype male (ZSM, examined by CSE), type locality Hashimiya, Irak. Female paratype from Abu Ghureib, Iraq, (ZSM, examined by CSE).

Remarks.

Polistes nimpha is well defined by male morphology, in particular the long apical antennal segment and distinct lateral ridges of the clypeus, and in the female by the colour pattern (European specimens only). In western Asia, the recognition of females is not always easy since the species varies markedly in colour pattern. It can be confused with P. associus (lowlands of Turkey, Israel) and with P. bucharensis (eastern Turkey, Caucasus region, Iraq). In a small geographic area in western Asia, the dark and the pale coloured form occur in close vicinity, but probably not sympatric. Especially specimens from Iraq have an extended yellow colour pattern and can be confused with P. bucharensis . They can be recognised by the colour of the hypopygium (=sternite VI), but identification of some females remains difficult.

Differences in the ocellar angle (more obtuse in P. nimpha / dominula than in P. associus ), as stated by Arens (2011), cannot be confirmed here. The sculpture of the lower half of the mesopleuron is somewhat coarser in P. nimpha than in P. associus , although both species overlap in this character.

Diagnosis.

The most important diagnostic character of P. nimpha females is the shape of the transverse pronotal band in that it is narrow and pointed ventrally. The lateral portion of the transverse band (seen in lateral view) is wider in front of the pronotal carina than behind it. In the remaining non-parasitic species of the P. dominula species group ( P. associus , P. dominula , and P. bucharensis ) the portion of the yellow band behind the carina is always wider. However, some extremely xanthic females of P. nimpha from western Asia also possess a very wide pronotal band. About 70% of females from western Asia have paired yellow drop-shaped spots on the mesoscutum. These spots are usually absent in European specimens. The visible part of the hypopygium (sternite VI) is usually black or partly reddish in P. nimpha and also in P. associus , rarely with a yellowish apical spot, while the hypopygium is entirely or predominantly yellow in P. dominula and P. bucharensis .

The latter character is used here for recognition of P. nimpha and P. bucharensis in eastern Turkey. This character is helpful in distinguishing xanthic P. nimpha females (i.e., with an all-yellow clypeus and temple), which are otherwise similar to P. bucharensis . Often only a combination of a several characters will ensure a correct identification of western Asian specimens.

The separation of P. associus and P. nimpha females can also be difficult, especially in areas where both species occur sympatrically (e.g. in western Croatia). The colour pattern of P. associus is diagnostic and exhibits little variation (based on specimens identified by barcoding): Transverse pronotal band wide laterally, separated from posterior band by 2-3 times the diameter of the anterior ocellus; mesoscutum with two large drop-shaped yellow spots. Despite significant variation, western Asian P. nimpha never show this combination of characters. The hypopygium colour is variable in both species but never all red in P. nimpha as it sometimes is in P. associus (one female from Israel).

Distribution.

Europe, north to S Finland, Palaearctic Asia east to Mongolia, China, and Russian Far East.

Specimens examined.

Europe: Germany, Italy (Alps), Bulgaria, Greece, France, Croatia, Portugal, Switzerland. Asia: Iraq, Turkey (Kars/Kagisman, Hakkari region, Denizli/Pamukkale, Antakya, Alanya, Marmaris, Diyarbakir).

Genetic results.

Only specimens from Central Europe were examined genetically, except for one specimen from Greece. The species shows significant intraspecific genetic variation. It is possible that the examination of Asian species will yield unexpected results.