Polistes helveticus Neumeyer

Neumeyer, Rainer, Baur, Hannes, Guex, Gaston-Denis & Praz, Christophe, 2014, A new species of the paper wasp genus Polistes (Hymenoptera, Vespidae, Polistinae) in Europe revealed by morphometrics and molecular analyses, ZooKeys 400, pp. 67-118 : 94-99

Polistes helveticus Neumeyer sp. n.

Polistes bischoffi Weyrauch, 1937: 274, in part - Weyrauch (1939), in part (paralectotype male, RN0325, of Polistes bischoffi , HUMCZ coll., Glattbrugg near Zurich, Switzerland). The following references published under the name of Polistes bischoffi Weyrauch, 1937 actually belong to Polistes helveticus sp. n.: Baugnée (1996), Blüthgen (1961), Dvořák and Roberts (2006), Dvořák et al. (2006), Graf (1961), Guiglia (1967, 1972), Kofler (2005), Mauss (2001), Mauss and Treiber (2004), Neumeyer et al. (2011), Schmid-Egger and Treiber (1989), Schneider et al. (1998), Witt (2009).

Polistes helveticus Holotype female (NMBE coll.), present designation, type locality Schwerzenbach, canton of Zürich, Switzerland

Diagnosis.

Small and relatively dark species with pedicel and flagellum black on upper side in both sexes (Figs 9a, 9b, 10a, 10c).

Females: Epicnemial carina reduced (Fig. 9c; red arrow) or absent. Hypopygium black (Fig. 9d). Metacoxa black. Mesoscutum black (Fig. 9e), only rarely with a minute pair of yellow spots. Propodeum laterally usually black (Fig. 9d), seldom with yellow spot on each side. Clypeus breadth: malar space 3.26-3.73; head breadth: malar space 7.29-8.8; malar space: lateral ocelli distance 0.87-1.19; metatibia length: malar space 7.61-9.33. terminal flagellomere length: malar space 0.81-1.07.

Males: Gena in dorsal view immediately narrowing behind eye (Fig. 12m). Epicnemium and mesosternum yellow (Figs 10a, 10c). Head breadth: head height 1.19-1.27; lower face: clypeus breadth 1.46-1.69; terminal flagellomere length: lateral ocelli distance 0.83-1.32; terminal flagellomere length: malar space 1.08-1.72; terminal flagellomere length: terminal flagellomere breadth 1.70-2.78.

Description of female.

Body length 9.7-14.1 mm (n = 20); forewing length 8.5-11.3 mm (n = 20).

Head: Clypeus yellow with black margin and large central black spot; this spot either isolated (Fig. 9a) or more often extended as crossband reaching the lateral margins of clypeus (Fig. 12g). Face with nearly triangular yellow spot touching inner orbit (Fig. 9a). Upper gena with small, elongate spot (Fig. 9d). Frons with pair of horizontal yellow stripes seldom confluent (Fig. 9a).

Mesosoma: Change in sculpture between coarse mesepisternum and smooth epicnemium frequently gradual (Fig. 12b). Pronotum along posterior margin with pair of longitudinal stripes not reaching cross stripe on pronotal collar (Fig. 9e). Scutellum and metanotum each with pair of yellow bars (Fig. 9e). Propodeum dorsally usually with pair of crescent-shaped spots (Fig. 9e). Mesopleuron with yellow spot (Figs 9c, 9d). Propodeal valve yellow (Fig. 9d). Tegula yellow anteriorly and posteriorly, with more transparent area in between (Fig. 9e). Legs yellow and orange, black only on coxa, trochanter and most of femur, including entire base (Figs 9d, 9e).

Metasoma: Each tergum with continuous, but slightly indented terminal yellow band (Figs 9d, 9e). Tergum 2 also with two yellow spots (Fig. 9e). Tergum 1 seldom with two small yellow spots. Sterna 2 and 3 with terminal yellow bands usually inter rupted, even though often only slightly so. Sterna 3, 4 and 5 with broadly interrupted terminal bands, manifested only as lateral terminal yellow spots.

Description of male.

Body length 9.6-12.4 mm (n = 12); forewing length 8.9-9.9 mm (n = 12).

Head: Mandibles, malar space, clypeus, face, inferior frons (Figs 10a, 10b) and elongate spot on upper gena (Fig. 10c) yellow. Superior frons, vertex (Fig. 10a), occiput and back of head (Figs 10c, 10d) black. Inferior part of frons yellow with small black area at superior margin of torulus, usually isolated (Fig. 10a; arrow), but seldom reaching the superior part of frons above. Clypeus apically rounded (Fig. 10a), with hardly any lateral ridge (Fig. 10b; arrows).

Mesosoma: Pronotum with yellow cross stripe along collar, occasionally extending down to sharp angle of pronotum (Fig. 10c; arrow). Legs yellow and orange, except for upper sides of coxa, trochanter and femur, which are black (Figs 10c, 10d); black area occasionally reaching (yellow) lower side of hind femur, yellow area occasionally reaching (black) upper side of pro- and mesocoxa. Rest of mesosoma colored as in females (Fig. 10d).

Metasoma: Tergum 2 with terminal yellow band extending laterally toward base, even if occasionally discontinuous. Other terga colored as in females. Sternum 2 most of the time with two yellow spots. Sterna 3, 4 and 5 usually with continuous terminal yellow band, the latter interrupted on sternum 6 and absent on hypopygium.

Comments.

Except for Polistes bischoffi , Polistes helveticus sp. n. is the only European species with an epicnemial carina that is often absent in the female sex. These two species are easy to distinguish in both sexes due to their differing color patterns, mainly on the antennae. Furthermore, the ratio metatibia length: malar space separates females, whereas the best separating ratio for males ( Polistes bischoffi , Polistes helveticus sp. n.) is terminal flagellomere length: malar space (Table 5). Confusion with Polistes gallicus or Polistes hellenicus is unlikely due to the very different color patterns in both sexes. Males are virtually impossible to confuse with Polistes biglumis ; however, the very similarly colored females of Polistes helveticus sp. n. and Polistes biglumis are likely to be confused in specimens of Polistes helveticus sp. n. with an exceptionally developed epicnemial carina. For such cases, we provide the ratio malar space: lateral ocelli distance, which fully separates the two.

Since most collected specimens labeled as " Polistes bischoffi " are presumed to belong to Polistes helveticus sp. n., rather than to Polistes bischoffi Weyrauch, 1937 (revised status), at least in Central European museums, their identity must be checked. In fact, according to the CSCF (www.cscf.ch; in litt.) there are about 450 individuals of Polistes helveticus sp. n. from Switzerland deposited in Swiss museums, but only very few (<10) individuals of Polistes bischoffi , at least before the material of the present study was deposited. A similar situation may apply to other Central European museums, especially in Austria and Germany. In contrast, the relatively few individuals labeled as " Polistes bischoffi " that we examined from Southern Europe (Greece, Italy, Southern France) are, in fact, determined correctly (mostly by Josef Gusenleitner).

The specimen that we have chosen as the holotype of Polistes helveticus sp. n. clearly belongs to Polistes helveticus sp. n. according to molecular and morphological analyses. According to its body measurements, however, it lies in an area of overlap with Polistes gallicus (Fig. 3a, c [H]). Unfortunately, it is the only specimen that was both intact and suitable for molecular analyses.

Distribution.

Fig. 11 only shows the distribution of the specimens examined within this study. Other possible records of Polistes helveticus (still under the name “bischoffi”) not shown in Fig. 11 include localities in Austria ( Gusenleitner 1995: 165; 1998: 497), Belgium ( Baugnée 1996), Czech Republic and Slovakia ( Dvořák et al. 2006), France ( Graf 1961), Germany ( Mauss 2001, Schmid-Egger and Treiber 1989), and Luxembourg ( Schneider et al. 1998).

Nevertheless, Fig. 11 indicates a geographical separation between Polistes helveticus sp. n. (in the north) and Polistes bischoffi (in the south), leaving only a small area of overlap. Real syntopy (habitat sharing) between the two species has thus far only been assessed in Switzerland but both species also occur sympatrically in Austria. Furthermore, the verified range of Polistes helveticus sp. n. (Fig. 11) is distinctly smaller than that of Polistes bischoffi , although Polistes helveticus sp. n. is considered to be in a period of expansion ( Dvořák et al. 2006, Mauss 2001).

Ecology.

In Switzerland, Polistes helveticus sp. n. is widespread (Fig. 11), usually occurring in wet habitats such as floodplains, fens, bogs, and pits (gravel, sand). The altitudinal records range from 200 m above sea level (Le Champ-près-Froges, France) for a female (individual RN0378) to 980 m a.s.l. (Muggio, Canton of Ticino, CH) for a male (RN0387). The seasonal records range from 02 April (Saint-Blaise, CH) for a female to 24 November (Gnadental, Germany) for a female (RN0283), but most individuals of both sexes are recorded in July and August (CSCF, in litt.). The earliest record for a male is on 21 July (Jestetten, Germany), the latest (RN0157) on 01 October (Courroux, CH). Nests are usually attached below 40 cm to vertical stems ( Ø 2-3 cm) of reed, alder, willow and other plants ( Kofler 2005; Neumeyer et al. 2011).

Etymology.

The Latin adjective "helveticus -a -um" means Swiss. The name Polistes helveticus sp. n. pays tribute to the country where the species was first discovered, when a female (Theodor Steck leg., NHMB coll.) was found in Bätterkinden (canton of Berne) in August 1882.

Material examined.

Holotype ♀ (RN0139): SWITZERLAND, CANTON ZURICH, Schwerzenbach, Böschen, 47°22'21.67"N, 08°40'01.43"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., NMBE coll.

Original Paralectotype ( Weyrauch 1939: 164) of Polistes bischoffi Weyrauch, 1937: 1 ♂ (RN0325): Switzerland, CANTON ZURICH, Glattbrugg, 8 Sep 1937, Wolfgang Weyrauch leg., HUMCZ coll., labeled as follows: 1. "W. Weyrauch" [printed], "Glattbrugg bei Zürich, 8.9.37" [handwritten]. 2. " Polistula bischoffi Weyrauch 1938" [handwritten]; 3. "Glattbrug [sic] nr Zurich Switzerland [handwritten; most probably added posteriorly]; 4. " Polistes bischoffi ♂ Weyr. paratype." [handwritten; probably added posteriorly].

Paratypes: 1 ♀ (RN0412): Austria, Burgenland, Stadtschlaining, Goberling, 18 May 1990, Michael Madl leg., NHMW coll.; 1 ♀ (RN0399): Czech Republic, South Bohemia, Stachy, Úbislav, 12 Oct 2005, village, Libor Dvořák leg., LD coll.; 1 ♂ (RN0398): Vlkov nad Lužnicí, 18 Sep 2004, P. Bogusch leg., LD coll.; 1 ♀ (RN0378): France, Isère, Le Champ-près-Froges, 200 m, 15 Aug 2003, sand pit, J. & I. Smit leg., JS coll.; 1 ♀ (RN0282) + 1 ♂ (RN0284): Germany, Baden-Württemberg, Blaustein, Lautertal westl. Weidach, 30 Aug 1988, Volker Mauss leg., RN coll.; 1 ♀ (RN0362): Kaiserstuhl, 30 Jun 1938, J.P. Wolf leg., ETHZ coll.; 1 ♀ (RN0283): Michelfeld, Gnadental, 24 Nov 1992, Volker Mauss leg., RN coll.; 1 ♀ (RN0388): Bavaria, Weichs, Weichser Moos, 48°22'55.2"N, 11°25'58.8"E, fen, 31 Jul 1991, Stephan Blank leg., SDEI coll.; 1 ♂ (RN0162): Principality of Liechtenstein, Ruggell, 47°13'56.98"N, 09°39'43.61"E, 444 m, 27 Aug 1996, dam, Simon Bieri leg., ETHZ coll.; 1 ♂ (RN0164): Schaan, 47°11'02.53"N, 09°31'29.11"E, 455 m, 24 Sep 1997, Simon Bieri leg., ETHZ coll.; 1 ♀ (RN0400): Slovakia, Trenčín Region, Bzince pod Javorinou, 06 Aug 2004, glade, Libor Dvořák leg., LD coll.; 1 ♀ (RN0230): SWITZERLAND, CANTON BASLE-City, Basel, Badischer Bahnhof, 47°34'50.12"N, 07°36'07.63"E, 255 m, 18 Aug 1995, ruderal field, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0377): CANTON BERNE, Bern, 22 Jul 1883, Theodor Steck leg., NMBE coll.; 1 ♀ (RN0374) + 2 ♂ (RN0375, RN0376): Bätterkinden, 24 Aug 1887, Theodor Steck leg., NMBE coll.; 1 ♂ (RN0161): Gampelen, Seewald, 16 Aug 1994, Richard Vernier leg., MHNN coll.; 1 ♂ (RN0158): CANTON Jura, Damphreux, Les Coeudres, 47°28'23.54"N, 07°06'34.74"E, 430 m, 22 Aug 2003, Christian Monnerat leg., MHNN coll.; 1 ♂ (RN0157): Courroux, Le Quenet, 47°22'46.78"N, 07°21'40.20"E, 510 m, 01 Oct 2004, Christian Monnerat leg., MHNN coll.; 2 ♂ (RN0155, RN0159): Courtemaîche, La Colombière, 47°27'48.87"N, 07°02'59.38"E, 390 m, 22 Aug 2003, Christian Monnerat leg., MHNN coll.; 1 ♂ (RN0386): CANTON Ticino, Meride, Fontana, 45°53'44"N, 08°56'46"E, 595 m, 24 Aug 1997, Ladislaus Rezbanyai-Reser leg., NML coll.; 1 ♂ (RN0387): Muggio, Muggiasca, 45°54'39"N, 09°01'21"E, 980 m, 16 Aug 1996, Ladislaus Rezbanyai-Reser leg., NML coll.; 1 ♀ (RN0394): CANTON Valais, Brig, 09 Aug 1916, anon. leg., ETHZ coll.; 2 ♂ (RN0198, RN0199): CANTON Vaud, Bussigny-près-Lausanne, 16 Aug 1962, Robert Matthey leg., MZL coll.; 1 ♀ (RN0360) + 1 ♂ (RN0361): Lausanne, Aug 1942, Jacques de Beaumont leg., MFNB coll.; 3 ♂ (RN0200, RN0203, RN0204): Lausanne, Vidy, 02 Aug 1943, Jacques de Beaumont leg., MZL coll.; 1 ♀ (RN0046): Noville, Longes Rayes, 46°23'21.32"N, 06°53'31.03"E, 273 m, 23 Aug 2011, shrubberies, Rainer Neumeyer leg., RN coll.; 5 ♀ (RN0047, RN0048, RN0049, RN0050, RN0051): 46°23'14.28"N, 06°53'34.66"E, 273 m, 23 Aug 2011, tall herbaceous vegetation, Rainer Neumeyer leg., RN coll.; 1 ♂ (RN0160): Saint-Livres, Les Mossières, 46°32'02.47"N, 06°21'55.82"E, 700 m, 21 Aug 2002, Christian Monnerat leg., MHNN coll.; 2 ♂ (RN0201, RN0202): Saint-Sulpice, Jul 1943, Jacques de Beaumont leg., MZL coll.; 1 ♂ (RN0114): Villars-sous-Yens, Arborex, 46°30'11.03"N, 06°25'12.11"E, 510 m, 25 Aug 2010, fen, Christian Monnerat leg., MHNN coll.; 2 ♀ (RN0277, RN0278): CANTON ZUG, Hünenberg, Rüssspitz, 47°14'09.40"N, 08°24'39.49"E, 389 m, 10 Jul 2012, fen, Rainer Neumeyer leg., ETHZ coll.; 1 ♀ (RN0279): 47°14'17.60"N, 08°24'27.75"E, 389 m, 20 Aug 2012, fen, Rainer Neumeyer leg., AMNH coll.; 1 ♀ (RN0275): CANTON ZURICH, Bauma, Fischbach, 47°23'00.66"N, 08°50'48.30"E, 660 m, 04 Jul 2012, abandoned pit, Rainer Neumeyer leg., RN coll.; 2 ♀ (RN0167, RN0168): 08 Aug 2012, abandoned pit, Rainer Neumeyer leg., CSE coll.; 1 ♂ (RN0152): Mönchaltorf, Seewisen, 47°19'17.63"N, 08°41'55.58"E, 436 m, 21 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., AMNH coll.; 1 ♀ (RN0003): Pfäffikon, Auslikon, 47°20'42.05"N, 08°47'52.78"E, 539 m, 20 Jun 2011, fen, Rainer Neumeyer leg., RN coll.; 3 ♀ (RN0018, RN0019, RN0020): 47°20'46.94"N, 08°47'50.38"E, 539 m, 10 Aug 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0078): Pfäffikon, Irgenhuserriet, 47°20'59.15"N, 08°47'49.98"E, 539 m, 06 Sep 2011, fen, Rainer Neumeyer leg., RN coll.; 2 ♀ (RN0033, RN0034): Seegräben, Schlachtmad, 47°20'23.35"N, 08°46'36.56"E, 537 m, 19 Aug 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ + 2 ♂ (RN0138, RN0153, RN0154): Schwerzenbach, Böschen, 47°22'21.67"N, 08°40'01.43"E, 436 m, same nest as holotype, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., NMBE coll.; 1 ♀ (RN0276): Weiach, Rüteren, 47°34'03.21"N, 08°26'44.70"E, 365 m, 02 Apr 2005, gravel pit, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0035): Wetzikon, Agerstenriet, 47°20'06.75"N, 08°46'57.43"E, 538 m, 19 Aug 2011, fen, Rainer Neumeyer leg., RN coll.; 2 ♀ (RN0012, RN0013): Wetzikon, Seeriet, 47°20'30.24"N, 08°47'10.89"E, 538 m, 05 Aug 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0081): 09 Sep 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0014): Wetzikon, Robenhuserriet, 47°20'19.16"N, 08°47'02.75"E, 538 m, 05 Aug 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0017): 47°20'16.20"N, 08°47'34.35"E, 539 m, 05 Aug 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♂ (RN0163): Zürich, <1900, anon. leg., ETHZ coll.