Polistes bischoffi Weyrauch, 1937

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 : 82-87

Polistes bischoffi Weyrauch, 1937 rev. stat.

Polistes bischoffi Weyrauch, 1937: 274 - Neotype female (NMBE), present designation, type locality Galeria, Corsica, France

Polistes cf. gallicus - Neumeyer et al. (2011)

Type study.

Polistes bischoffi was described by Weyrauch (1937: 274) in a mere footnote indicating neither the type material nor the type locality. Later, Weyrauch (1938: 277 ff.) gave a key to the Palearctic species of Polistes , including Polistes bischoffi , but a more precise indication of the type material and the type locality is given only in Weyrauch (1939: 163), where a female from Macomer (Sardinia, Italy) is mentioned as the "type [Typus]". However, following article 74.5 of the ICZN (2012) this specimen is considered as a lectotype here. Unfortunately, this lectotype is lost ( Blüthgen 1956: 85), as well as most paralectotypes from various localities (Italy, Malta, and Turkey; see Weyrauch 1939: 164), with the exception of two presumed paralectotypes that we were able to examine: a female (RN0287) from the Greek Island of Poros (see below, examined material), and a male (RN0325) from Glattbrugg in Switzerland. While the male from Glattbrugg clearly belongs to the dark (Fig. 10), northern (Fig. 11) taxon ( Polistes helveticus sp. n.), the female from Poros belongs without any doubt to the southern (Fig. 11), bright (Fig. 6) taxon ( Polistes bischoffi ). Consequently, Weyrauch (1939) most likely considered both taxa as geografically separated color morphs of the same species. Evidence for this statement can be found in his redescription of Polistes bischoffi ( Weyrauch 1939: 163 ff.), where he writes that the antenna is "dorsally blackened in the northern part of the species range [ Fühler im Norden des Verbreitungsgebietes oberseits geschwärzt]”.

It must be stressed that both taxa ( Polistes bischoffi , Polistes helveticus sp. n.) run to “bischoffi” in the keys of Weyrauch (1938: 277 ff.; 1939: 195 ff.). In more recent keys ( Blüthgen 1961, Dvořák and Roberts 2006, Guiglia 1972, Mauss and Treiber 2004, Witt 2009) for Central Europe however, Polistes helveticus sp. n. would run to “bischoffi”, whereas Polistes bischoffi would run to “gallicus” due to the entirely bright flagellum.

Unfortunately, the identity of the lost lectotype from Macomer (Sardinia, Italy) is unclear and can not be guessed from Weyrauch (1937, 1938, 1939). Therefore, the designation of a neotype is necessary for the clarification of the identity of Polistes bischoffi . Our attempts to locate the lectotype in all institutions likely to host some of Weyrauch’s material were unsuccessful (e.g.: MFNB, Michael Ohl, pers. comm.; MHNL, Claus Rasmussen, pers. comm.; FMLT, Emilia Perez, pers. comm.), and so were our attempts to locate any specimen of Polistes bischoffi from Sardinia, including during a field trip to Macomer in 2013. Consequently, we designate a female from Galeria on the island of Corsica (France), north of Sardinia, as the neotype of Polistes bischoffi . Given that there is only a distance of 12 km between the two neighboring islands (Corsica, Sardinia), and that both of them share a similar fauna ( Corti et al. 1999; Kwet 2005; Tolman and Lewington 1997), we are confident that this specimen matches the lost lectotype of Polistes bischoffi Weyrauch, 1937. In fact both, Corsica and Sardinia are probably located too far south to host the taxon called Polistes helveticus sp. n. here, since the southernmost individual (RN0378) of Polistes helveticus sp. n. that we are familiar with was found about 200 km north of the French Mediterranean coast (Fig. 11). Moreoever, the neotype is a well preserved female of the southern, light colored species ( Polistes bischoffi ) that appears at the center of the scatter of points in our morphometric analysis and clearly lies outside the area of overlap with Polistes gallicus (Fig. 3a, c [C]). Lastly, this specimen (RN0366) yielded high-quality DNA and could be included in our molecular analysis.

Diagnosis.

Small and moderately bright species with flagellum on upper side bright yellow in both sexes (Figs 6a, 6c, 6d, 7a, 7b, 7d, 7e) or faintly darkened, especially in large females; pedicel and extreme base of flagellomere 1 always black on upper side.

Females: Epicnemial carina reduced (Figs 6c, 12b) or absent. Hypopygium black. Metacoxa usually black, seldom spotted yellow on upper side. Mesoscutum usually black, seldom with minute pair of yellow spots (Fig. 6e; arrow). Propodeum laterally usually with yellow spot (Fig. 6c; arrow). Clypeus breadth: malar space 3.85-4.55; head breadth: malar space 9.02-10.89; malar space: lateral ocelli distance 0.79-1.11; metatibia length: malar space 9.57-11.5; terminal flagellomere length: malar space 1.00-1.24.

Males: Gena in dorsal view immediately narrowing behind eye (Fig. 12m). Epicnemium and mesosternum yellow. Head breadth: head height 1.21-1.29; lower face: clypeus breadth 1.47-1.63; terminal flagellomere length: lateral ocelli distance 1.19-1.55; terminal flagellomere length: malar space 1.93-2.75; terminal flagellomere length: terminal flagellomere breadth 2.46-2.87.

Description of female.

Body length 9.9-14.1 mm (n = 22); forewing length 7.8-11.4 mm (n = 22).

Head: Clypeus yellow, with a black margin and a large central black spot usually isolated (Fig. 6a) but seldom shaped like a (rhomboid) crossband reaching lateral margin. Face with large, almost triangular yellow spot touching inner orbit (Fig. 6a). Upper gena with small, elongate spot (Figs 6c, 6d). Frons with usually uninterrupted horizontal yellow stripe (Fig. 6a).

Mesosoma: Change in sculpture between coarse mesepisternum and smooth epicnemium frequently gradual (Fig. 12b). Pronotum along posterior margin with pair of longitudinal yellow stripes not reaching yellow cross stripe on pronotal collar (Fig. 6e). Scutellum with pair of yellow, somewhat triangular spots, followed by rectangular pair of spots on metanotum and crescent-shaped pair of spots on dorsal propodeum (Fig. 6e). Mesopleuron with yellow spot (Figs 6c, 6d). Propodeal valve yellow (Fig. 6c). Tegula yellow anteriorly and posteriorly, with transparent area in between (Fig. 6e). Legs apically yellow and orange, black only on coxa, trochanter and most of femur (Figs 6d, 6e), including base.

Metasoma: Each tergum with continuous, but indented terminal yellow band (Figs 6d, 6e). Tergum 2 also with two large yellow spots (Fig. 6e). Tergum 1 occasionally with two small yellow spots. Sterna 2 and 3 with continuous terminal yellow bands, on sternum 3 occasionally centrally indented close to interruption. Sternum 4 with interrupted terminal yellow band. Sternum 5 with broadly interrupted terminal band, reduced to two lateral yellow spots.

Description of male.

Body length 11.3-13.4 mm (n = 8); forewing length 9.3-9.8 mm (n = 8).

Head: Mandibles, malar space, clypeus (Figs 7a, 7b), elongate spot on upper gena (Figs 7c, 7d, 7e), face and inferior frons yellow. Superior frons, vertex, occiput and back of head black (Figs 7a, 7c, 7e). Clypeus apically rounded (Fig. 7a), with faint lateral ridges extending toward orbital bays (Fig. 7b; arrow).

Mesosoma: Pronotum with yellow cross stripe along collar, often extending down both sides to longitudinal pair of yellow stripes along pronotal side margin (Fig. 7d; white arrow). Epicnemium and mesosternum yellow (Fig. 7d). Legs yellow and partially orange, except for superior side of coxa, trochanter and femur, which are black (Figs 7d, 7e). Rest of mesosoma colored as in females.

Metasoma: Tergum 2 with terminal yellow band laterally extending towards base (Fig. 7d; red arrow), even if occasionally interrupted. Terga otherwise colored as in females. Sternum 2 with pair of large yellow spots mostly isolated (Fig. 7d; black arrow), seldom fused. Sternum 3 with both terminal and basal yellow bands (Fig. 7d; blue arrow). Sterna 4 and 5 both with continuous terminal yellow band, the latter interrupted on sternum 6 and absent on hypopygium.

Comments.

This is one of the smallest Polistes species in Europe and besides Polistes helveticus sp. n., the only one with often absent epicnemial carina in the female sex. The two locally syntopic species (Fig. 11; Neumeyer et al. 2011) are, however, easy to distinguish in both sexes due to differently colored antennae. Furthermore, the ratio metatibia length: malar space is an unambiguous separator for females, whereas the best separating ratio for males ( Polistes bischoffi , Polistes helveticus sp. n.) is the ratio terminal flagellomere length: malar space (Table 5). The same ratio weakly separates the sometimes similar females of Polistes bischoffi and Polistes gallicus . It is impossible to confuse the males of Polistes bischoffi with the males of Polistes hellenicus or Polistes biglumis due to the strikingly different color patterns and the diagnostic head shape of Polistes biglumis males within the gallicus-group.

Two morphs can be distinguished within Polistes bischoffi (rev. status), one with the flagellum entirely bright (yellow to orange) and the other with the flagellum dorsally faintly darkened. Often, the brighter morph (e.g. RN0137) has the clypeus with a central black spot (Fig. 6a), whereas in the darker morph the clypeus usually has a horizontal black band reaching the lateral margin. These two color morphs are probably the two extremes of an otherwise gradual continuum, but more individuals would have to be examined to verify this hypothesis. It would be even more important to examine whether such color variations are associated with geography or not. Limited evidence suggests that these variations are not associated with geographic location, since two nests were found (16 Aug 2013) in Zurich (Katzensee Allmend) with both morphs in each. In these colonies, the dark morph was more common among large females (presumably young queens), rather than among small females (presumably workers) or males. Also the neotype (RN0366) of Polistes bischoffi belongs to the darker morph and is presumably a queen, since it was collected on 19 April. More observations are needed to confirm this correlation between coloration and caste. Different color morphs within the same nest population are also reported in Polistes gallicus ( Gusenleitner 1985: 105).

Distribution.

Based on the material that we have examined, Polistes bischoffi occurs at least in Southern Europe and Turkey from the Atlantic coast of southern France to Turkish Kurdistan (Fig. 11). The northernmost confirmed locality is in the Pannonian region of Austria (Neusiedl am See), followed by several localities in Switzerland where the species occured already in 1927 at the river Versoix near Geneva (individuals RN0170, RN0171). In all other, more northern Swiss sites Polistes bischoffi occurs syntopically ( Neumeyer et al. 2011) with Polistes helveticus sp. n. and was not detected before 1992, suggesting a possible recent range expansion due to climate warming.

Ecology.

According to our experience in Switzerland, Polistes bischoffi appears to be restricted to large wetlands, especially to fens on lake shores, more so than Polistes helveticus sp. n. The altitudinal records range from sea level for several beach records (see "Material examined"), including the neotype (RN0366), to 540 m a.s.l. for a female (RN0076) in Switzerland (Wetzikon, Canton of Zurich). However, the Turkish locality (road from Yüksekova to Şemdinli) where three females (RN0363, RN0364, RN0365) were found was probably higher than 540 m a.s.l., since Yüksekova is situated at 1950 m, Şemdinli at 1450 m a.s.l., but the precise elevation of the locality is neither indicated on the label nor in the publication ( Madl 1997: 824). Most individuals were found in August or September. The earliest record in the season is the neotype female from Galeria on 19 Apr 2002, the latest a female from a still-active nest in Mönchaltorf on 10 September 2010. The earliest male (RN0022) recorded so far was captured at Pfäffikon (Switzerland) on 10 Aug 2011, whereas the latest males (RN0082, RN0083) recorded are from Wetzikon on 09 Sep 2011. Nesting habits are apparently similar to those of Polistes helveticus sp. n., even where the two species were encountered syntopically ( Neumeyer et al. 2011). We also found two nests in Zurich (Katzensee Allmend, 16 Aug 2013) with more than 20 and 30 individuals, respectively. These two nests were larger than any of the 14 nests described by Neumeyer et al. (2011: 13). While the smaller of both nests was attached to the dry stem of an Apiaceae , the larger one was attached to the stem of a live yellow loosestrife ( Lysimachia vulgaris ).

Material examined.

Neotype ♀ (RN0366): France, Corsica, Galeria, 42°25'11"N, 08°39'37"E, 0 m, 19 Apr 2002, estuary, Christian Monnerat leg., NMBE coll.

Paralectotype: 1 ♀ (RN0287): Greece, ATTICA, Poros, Moritz von Leonhardi (1856-1910) leg., SDEI coll., labeled as follows: 1. “Poros” [handwritten; misspelled as “Toros” in Weyrauch 1939: 164; see Blüthgen 1961: 56]; 2. "Coll. v. Leonhardi" [printed]"; 3. "Poliistes [sic!] ♀ gallicus L." [handwritten, possibly from v. Leonhardi; according to Stephan Blank (pers. comm.)]; 4. "Weyrauch det. 1937." [handwritten]; 5. "Polistula bischoffi Weyrauch" [handwritten; possibly from Weyrauch; according to Stephan Blank (pers. comm.)]".

Further material: 1 ♀ (RN0415): Austria, Burgenland, Neusiedl am See, 25 Jul 1989, Michael Madl leg., NHMW coll.; 1 ♀ (RN0414): 20 Aug 1991, Michael Madl leg., NHMW coll.; 1 ♀ (RN0323): FRANCE, BOUCHES- DU-RHÔNE, Miramas, Étang de Berre, 15 Jul 1979, M. Kühbandner leg., MSNV coll.; 1 ♀ (RN0380): Saintes-Maries-de-la-Mer, Camargue, 28 Jul 2002, J. & I. Smit leg., JS coll.; 1 ♀ (RN0381): Hérault, Vendres, 43°13'00"N, 03°14'38"E, 0 m, 29 Jul 2009, beach, J. & I. Smit leg., JS coll.; 2 ♀ (RN0382, RN0383): Palavas-les-Flots, 04 Jul 2005, dunes, J. & I. Smit leg., JS coll.; 1 ♀ (RN0379): Landes, Vielle-Saint-Girons, Huchet, 04 Jul 2006, dunes, J. & I. Smit leg., JS coll.; 2 ♀ (RN0367, RN0368): Var, Fréjus, Saint-Aygulf, Jul 1924, Ferrière leg., NMBE coll.; 1 ♀ (RN0385): Roquebrune-sur-Argens, 14 Jul 2001, J. & I. Smit leg., JS coll.; 1 ♀ (RN0384): road (D560) from Saint-Maximin-la-Sainte-Baume to Nans-les-Pins, 350 m, 15 Jul 2001, J. & I. Smit leg., JS coll.; 1 ♀ (RN0370): Vaucluse, Villelaure, 18 Jul 2000, Jan Smit leg., JS coll.; 1 ♀ (RN0391): GREECE, Achaea, Kalogria, 01 Jul 2007, spit, Werner Arens leg., WA coll.; 1 ♀ (RN0390): Arcadia, Mantineia (archaeological site), 12 Jul 1997, Werner Arens leg., WA coll.; 1 ♀ (RN0389): 06 Jul 2007, Werner Arens leg., WA coll.; 2 ♀ (RN0372, RN0373): Euboea, Chalkida, Camping Paradiso, 15 Jul 1982, M. & G. Osella leg., MCSNV coll.; 2 ♀ (RN0392, RN0393): Laconia, Chosiari, Vathi, 09 Jun 1998, beach, Werner Arens leg., WA coll.; 1 ♀ (RN0322): ITALY, LAZIO, Roma, Torrimpietra, 10 Aug 1971, Heiss leg., MSNV coll.; 1 ♀ (RN0410): Roma, Sep 1942, O. Querci, MSNM coll.; 1 ♀ (RN0411): Lombardia, Guardamiglio, Fiume Po, 12 Aug 1974, river bank, Vincenzo Ferri leg., MSNM coll.; 1 ♀ (RN0409): Piemonte, Cameri, Cascina Galdina, 11 Jul 1981, glade, Vincenzo Ferri leg., MSNM coll.; 1 ♀ (RN0371): Lombardore, Sep 1972, Osella leg., MCSNV coll.; 2 ♀ (RN0170, RN0171): SWITZERLAND, CANTON GENEVA, Versoix, "vers la Versoix", 1 Jul 1927, anon. leg., MHNG coll.; 1 ♀ (RN0156): CANTON VAUD, Chabrey, La Morette, 8 Sep 1992, fen, Richard Vernier leg., MHNN coll.; 4 ♀ (RN0135, RN0136, RN0141, RN0148): CANTON ZURICH, Greifensee, Böschen: 47°22'21.46"N, 08°40'03.38"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., MZL coll.; 1 ♀ + 1 ♂ (RN0147, RN0150): 47°22'21.46"N, 08°40'03.38"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., AMNH coll.; 1 ♀ (RN0146): 47°22'20.36"N, 08°40'02.49"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., CM coll.; 1 ♀ (RN0142): 47°22'20.59"N, 08°40'02.64"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., MH coll.; 1 ♀ (RN0137) + 1 ♂ (RN0151): Mönchaltorf, Seewisen, 47°19'17.08"N, 08°41'56.05"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., NMBE coll.; 1 ♀ (RN0140): 47°19'17.80"N, 08°41'54.97"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., CSE coll.; 1 ♀ (RN0001): Pfäffikon, Auslikon, 47°20'47.75"N, 08°47'50.16"E, 539 m, 10 May 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♂ (RN0022): Pfäffikon, Birchen, 47°21'03.19"N, 08°47'31.73"E, 538 m, 10 Aug 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0169): Regensdorf, Altburg, 24 Jul 1997, hill near fen, Bernhard Merz leg., MHNG coll.; 1 ♀ (RN0145): Schwerzenbach, Böschen, 47°22'21.48"N, 08°40'01.19"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., NML coll.; 1 ♀ (RN0149): 47°22'21.35"N, 08°40'00.85"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., NHMB coll.; 1 ♀ (RN0143): 47°22'21.39"N, 08°40'00.75"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., ETHZ coll.; 1 ♀ (RN0144): 47°22'21.39"N, 08°40'00.90"E, 436 m, 11 Aug 2010, fen rotation fallow, Rainer Neumeyer leg., MCSNL coll.; 1 ♀ (RN0076): Wetzikon, Himmerich: 47°20'07.85"N, 08°47'31.05"E, 540 m, 02 Sep 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0105): Wetzikon, Robenhuserriet, 47°20'11.31"N, 08°47'14.84"E, 538 m, 17 Aug 2012, fen, Rainer Neumeyer leg., BNM coll.; 1 ♂ (RN0075): Wetzikon, Seeriet, 47°20'30.24"N, 08°47'10.89"E, 538 m, 02 Sep 2011, fen, Rainer Neumeyer leg., RN coll.; 2 ♂ (RN0082, RN0083): 47°20'30.24"N, 08°47'10.89"E, 538 m, 09 Sep 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♀ (RN0077): 47°20'29.54"N, 08°47'23.73"E, 537 m, 02 Sep 2011, fen, Rainer Neumeyer leg., RN coll.; 1 ♂ (RN0328): Zürich, Katzensee Allmend, 47°25'53.05"N, 08°30'26.15"E, 438 m, 16 Aug 2013, fen, André Rey leg., AR coll.; 4 ♀ (RN0329, RN0330, RN0331, RN0332) + 3 ♂ (RN0333, RN0335, RN0336): 19 Aug 2013, Rainer Neumeyer leg., RN coll.; 1 ♂ (RN0334): 19 Aug 2013, Rainer Neumeyer leg., NHM coll.; 2 ♀ (RN0337, RN0338) + 2 ♂ (RN0339, RN0340): 47°25'56.74"N, 08°30'22.41"E, 438 m, 19 Aug 2013, fen, Rainer Neumeyer leg., RN coll.; 3 ♀ (RN0363, RN0364, RN0365): Turkey, Hekarî, road from Yüksekova to Şemdinli [ “Sendili”], 1450-1950 m, marshy meadow [Sumpfwiese], 05 Jun 1971, Michael Madl leg., NHMW coll.