Polistes bucharensis Erichson

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 : 84-86

Polistes bucharensis Erichson stat. rev. Figs 8, 9

Polistes bucharensis Erichson, 1849, Mem. Acad. Sci. St. Petersburg (6)6: 307. Holotype female (depository unknown), type locality: Uzbekistan Bokhara (= Bukhara). Sp. restit.

Polistes gallica var. ornata Weyrauch, 1938, Arbeit. Physiol. Angewand. Entomol. Berlin-Dahlem 5: 278, nec Lepeletier, 1836. Female lectotype (lost), designated by Weyrauch (1939: 154), type locality: Astrabad [Gorgan], Iran. Syn. n. (previously considered a synonym of P. dominula )

Polistes gallica var. pacifica Weyrauch, 1939, nec Fabricius, 1804, Arch. Naturgesch. (N. F.) 8: 155 156. Holotype female (depository unknown), type locality: China. Synonymy likely but requiring confirmation through examination of types.

Polistes gallicus pseudopacificus Giordani Soika, 1970, Ann. Hist.-Nat. Mus. Natl. Hung., Zool. 62: 326. Replacement name for pacificus Weyrauch, 1939, nec Fabricius, 1804.

Polistes iranus Guiglia, 1976, Boll. Mus. Civ. Stor. Nat. Venezia 28 (1976): 99; description of male and female. Holotype female (MSNV, not examined), type locality Daria Namak [salt steppe near Dariun], Fars (Iran). Syn. n.

Polistes gallicus muchei Gusenleitner, 1976, Nachrichtenbl. Bayer. Entomol. 25(6): 118. Holotype male (OLL, not examined), type locality: Kislovods [Kislovodsk], northern Caucasus (Russia). Paratypes from Kislovodsk and from Turkey/Artvin. Six male paratypes (MFNB, examined by CSE). Syn. n. (previously considered a synonym of P. dominula )

Remarks and genetic data.

Polistes bucharensis is recognized as a valid species distinct from P. dominula here. Its taxonomic status has been controversial. It was formerly treated as valid species ( P. iranus ) by Guigla (1976), as subspecies of P. dominula (e.g. Gusenleitner 1976), or as a synonym of P. dominula ( Carpenter 1996). In our opinion P. bucharensis is clearly distinguishable from P. dominula by colour pattern, by shape of the male clypeus and by the genetic data.

Specimens from Mongolia and China (= Polistes gallicus pseudopacificus) probably belong to P. bucharensis and not to P. dominula , as indicated by Giordani Soika (1970).

The species was first described from Uzbekistan and later as Polistes gallica var. ornata and as Polistes iranus from Iran. It was not possible to examine types of these taxa, but their descriptions agree well with examined specimens. Also, we could examine a large series of specimens from the type locality of P. bucharensis from Bukhara in MFNB, which also agree with description of P. bucharensis . Therefore, the valid name for this taxon is Polistes bucharensis Erichson, 1849 sp. restit.; and Polistes iranus syn. n. is a new synonym of P. bucharensis .

Another problematic taxon in this group is P. gallicus muchei. It was described by Gusenleitner (1976) from northern Caucasus and eastern Turkey as a subspecies of P. gallicus (now P. dominula ) based on reduced pale marks in the male and whitish yellow or ivory instead of yellow ground colour. Six male paratypes and a non-type male from eastern Turkey (Kars, identified by J. Gusenleitner as P. gallicus muchei, in coll. CSE) were examined by CSE. They agree with typical P. bucharensis by having the mesosternum black and the clypeal ridges present. The male from Kars differs by an all-black mesonotum and by a black medial spot on clypeus. Consequently, we treat muchei (based on males) as a dark and whitish colour form of P. bucharensis and not as a form of P. dominula (= former P. gallicus ). It is probably restricted to mountainous regions of NE Turkey and the Caucasus. This assignment is based on colour and morphology alone and requires verification through sequence data.

According to the description by Gusenleitner (1976), the female paratypes of P. muchei differ markedly from typical P. bucharensis by a reduction of the pale body colour. The mesoscutum is black and the clypeus has a transverse band. We cannot rule out that the type series of P. muchei includes P. nimpha specimens. Two non-type females from Kagisman (eastern Turkey, collected by CSE together with the above-mentioned male) belong to two species: one to P. bucharensis (typical form) and other to P. nimpha (with extreme extended pale colour pattern: clypeus and genae all yellow, however, with the mesoscutum and the hypopygium (sternite VI) all black.

Based on the material that was available for us it appears that two taxa of this lineage occur in eastern Turkey and the Caucasus: P. bucharensis and P. nimpha . Males can be recognized easily by morphological characters (see key to species), whereas the identification of females is hampered by an extraordinary colour variation (extreme pale forms occur together with extreme dark forms). They can be distinguished by characters given in the key (mainly by colour of the hypopygium (sternite VI): yellow in P. bucharensis , mainly black or reddish in P. nimpha ). In addition, the sculpture of the lower half of the mesopleuron is coarser in P. bucharensis than in P. nimpha (where it is finer, with overlap in a few specimens). Results of DNA barcoding of females is needed to confirm this hypothesis. Another problem is a white coloured form of P. nimpha in Iraq ( P. nimpha irakensis, see discussion under P. nimpha ).

The MFNB houses a large series of females from West Pamir, collected in 1928 by Reinig. This taxon is darker than typical P. bucharensis from Bukhara or Turkey (yellow band on gena of female medially largely interrupted, mesoscutum black, tergites with narrow pale bands, and pale colour whitish instead of yellow). The specimens have the clypeus all whitish yellow, the clypeal disc is punctate with large punctures and has some bristles. They probably also represent a dark high-elevation form of P. bucharensis . The colour variation of Central Asian specimens is not understood well and requires examination of more material.

Three barcoded specimens from Crete were assigned a separate BIN (Tab. 1). Their colour pattern is intermediate between P. bucharensis and P. dominula (see description below) but genetically they are most similar to P. bucharensis from Cyprus. Therefore, we treat them as an island form of P. bucharensis . It is possible that the population from Crete represents a distinct species but further research is required to clarify the taxonomic status of the involved species.

The specimens barcoded fall into four clusters that were assigned three different BINs (Suppl. material 2: NJ tree). The species shows distinct geographic subclustering with specimens originating from Crete, Cyprus, and Azerbaijan. Specimens from Crete differ morphologically distinctly from those of Cyprus (see discussion above), whereas two of the examined specimens from Azerbaijan are similar to the specimens from Cyprus.

A single specimen from Azerbaijan has been assigned a different BIN, whereas another specimen from Azerbaijan that is morphologically similar to the remaining females of P. bucharensis agrees genetically with P. dominula from Central Europe (Suppl. material 2: NJ tree). More specimens from this region need to be examined to be able to assess the morphological variation of each potential species in this group and its status in relation to P. dominula . It is probable that several other genetically distinct taxonomic units of this P. dominula / P. bucharensis species complex occur in this region.

Diagnosis.

Polistes bucharensis is similar to P. dominula , and both sexes can be distinguished by the continuous wide yellow band on the temple (gena); seen in lateral view it is more than half as wide as the temple and extends along the entire posterior margin of the eye (specimens from Crete are different, see below). In P. dominula , this band is medially interrupted and less than half as wide as the temple, rarely continuous but then it is constricted medially. In females, the yellow band above the antennae is always connected with the band along the inner eye margin. This band is isolated from the lateral bands in P. dominula and it does not reach the inner eye margin.

Females of P. bucharensis have an entirely yellow clypeus and a somewhat denser pilosity on the clypeus (the pilosity concerns the dark bristles on the clypeal surface). In females of P. dominula the colour of the clypeus is variable: entirely yellow (mainly in specimens from Central Europe) or with a black medial spot in 50-70% of specimens from southern Europe and western Turkey (fig. 38/39).

Sternite II is predominantly black with narrow apical yellow band in P. bucharensis , the visible part of the remaining sternites is entirely yellow (except in specimens from Cyprus, which have a larger basal part of sternite III black). In P. dominula , the visible base of the sternites III-V is always black and the apical yellow band is 0.5-0.7x as wide as the total visible part of the sternite. Additionally, the species can be recognised by the sculpture of the mesopleuron and the lateral face of the propodeum that is markedly coarser in females of P. bucharensis compared to P. dominula .

Males of P. bucharensis have the mesosternum always all black, whereas the mesosternum of P. dominula males is partly or entirely yellow. The mesosternum has at least two triangular yellow spots subapically (except in specimens from southern Greece, see below). The colour pattern of the sternites is more variable than in females. For distinction from P. nimpha and from species of higher mountains in Central Asia see the key to species and the discussion above.

Variations.

Females from Crete (n = 6) differ from typical P. bucharensis by a reduction of the yellow body colour. The yellow band of the temple (gena) in lateral view is medially widely interrupted and the clypeus has nearly always a transverse band or medial spot (Fig. 35), except one female with entirely yellow clypeus. The yellow band above the antennal sockets is isolated from both lateral bands. Sternites III-VI are all yellow and sternite II has only a narrow yellow apical band.

The single male that was examined genetically has the mesosternum all black and the yellow band of the temple is medially interrupted. In specimens from Iran the yellow body colour of the only examined male from Arak is replaced by an extreme whitish yellow. For recognition of specimens from Caucasus and E Turkey see discussion on P. dominula muchei.

Distribution.

From Central Turkey to Central Asia, Israel, Iran and Egypt. In Europe only known from Crete and Cyprus. Specimens described from China and Mongolia (not examined) may also belong to P. bucharensis (see Giordani Soika, 1970).

Specimens examined.

Europe: Greece (Crete), Cyprus. Asia: Turkey (Diyarbakir, Hakkari, Van, Esendere, Mersin, Goreme, Kars/Kagisman), Iran (Arak/Besril), Azerbaijan, Uzbekistan (Bukhara), Israel (Arava Valley). Africa: Egypt (female, Oasis Dakhla, 2.ix.1992, CSE).