Wednesday, May 17, 2017

[Entomology • 2017] Melitaea acentria • A New Species of Melitaea from Israel, with Notes on Taxonomy, Cytogenetics, Phylogeography and Interspecific Hybridization in the Melitaea persea complex (Lepidoptera, Nymphalidae)


Melitaea acentria Lukhtanov, 2017

Photos by V. Lukhtanov    DOI: 10.3897/CompCytogen.v11i2.12370 

Abstract
Specimens with intermediate morphology are often considered to be the result of ongoing interspecific hybridization; however, this conclusion is difficult to prove without analysis of chromosomal and/or molecular markers. In the butterfly genus Melitaea, such an intermediacy can be detected in male genitalia, and is more or less regularly observed in localities where two closely related, presumably parental species are found in sympatry. Here I analyze a high altitude Melitaea population from Mt. Hermon in north Israel and show that its male genitalia are clearly differentiated from those found in phenotypically similar M. persea and M. didyma, but in some aspects intermediate between them. This hybrid-like population is unique because, although M. didyma is present on Mt. Hermon, the true, low-altitude M. persea has never been reported from Israel. Cytogenetic analysis revealed no apomorphic chromosomal characters to distinguish the Mt. Hermon population from other known taxa of the M. persea and M. didyma species groups. At the same time, DNA barcode-based phylogeographic study showed that this population is ancient. It was estimated to originate 1–1.6 million years ago in the Levantine refugium from a common ancestor with M. persea. Generally, the data obtained are incompatible with interpretation of the studied population as a taxon conspecific with M. persea or M. didyma, or a swarm of recent hybrids between M. persea and M. didyma, although the possibility of ancient homoploid hybrid speciation cannot be ruled out. I also argue that the name Melitaea montium assigned to butterflies from north Lebanon cannot be applied to the studied taxon from Mt. Hermon. Here I describe this morphologically and ecologically distinct entity as a new species Melitaea acentria sp. n., and compare it with other taxa of the M. persea complex.

Keywords: Chromosomes, COI, DNA barcoding, genitalia, homoploid hybrid speciation, interspecific hybridization, Middle East, Melitaea casta, Melitaea eberti, Melitaea higginsi, Melitaea deserticola, Melitaea trivia, morphology, nomenclature, taxonomy

Figure 2. Melitaea acentria sp. n.
  
holotype, male, 17949_A06, Israel, Mt. Hermon; upperside holotype, male; underside male, 25453_E09, Israel, Mt. Hermon d paratype, female, 25453_E11, Israel, Mt. Hermon  
Photos by V. Lukhtanov    DOI: 10.3897/CompCytogen.v11i2.12370

Melitaea acentria Lukhtanov, sp. n.

 Holotype: (Fig. 2a, b), male, BOLD process ID BPAL2191-13, field # CCDB-17949_A06, GenBank accession number # KY777529; Israel, Mt. Hermon, 2050 m, 01 June 2013, A. Novikova leg., deposited in the Zoological Institute of the Russian Academy of Science (St. Petersburg).

Figure 3. Melitaea acentria in nature. Female. Israel, Mt. Hermon, 1800 m, 07 May 2016.
Photos by V. Lukhtanov
 
 DOI: 10.3897/CompCytogen.v11i2.12370 

Figure 13. Melitaea acentria and its habitat. Israel, Mt. Hermon, 2040 m, 22 June 2013.  

Distribution: Melitaea acentria is known to occur at high altitudes (1730–2060 m above the sea level) of Mt. Hermon (Fig. 11). Within these altitudes it is sympatric and syntopic with M. trivia syriaca, M. deserticola and M. cinxia. At the altitudes 1730–1780 m there is an essential overlapping of the M. acentria and M. didyma liliputana ranges where both species were found to fly together in early May 2016. Two other Melitaea species known from Mt. Hermon, M. collina and M. telona, were found to fly mostly at lower altitudes 1000–1600 m.

Etymology: The name acentria is a noun of the feminine gender. This name originates from the Greek prefix “a” that means “not” and from the Latin word “centrum” (centre) derived from the Greek “κέντρον” (kentron, a sharp point). Acentria is the Internet nickname of Asya Novikova who collected the samples initiated this research.This name indicates also the peripheral position of the new species within the distribution range of the M. persea species complex.

Figure 2. Melitaea acentria sp. n. and M. persea persea.
Macentria sp. n., holotype, male, sample 17949_A06, Israel, Mt. Hermon; upperside Macentria sp. n., holotype, male, sample 17949_A06, Israel, Mt. Hermon; underside Macentria sp. n., paratype, male, sample 25453_E09, Israel, Mt. Hermon Macentria sp. n., paratype, female, sample 25453_E11, Israel, Mt. Hermon
e M. persea persea, male, 17966_A10, Iran, Fars prov., Fasa area, 20 km W Estahban, 2200 m, 9-11 May 2007, B. Denno coll., MGCL accession # 2010-20 f M. persea persea, female, 17951_B01, Iran, Fars prov., 20 km N Darab, 2100-2300 m, 24.05.1999, leg. P. Hofmann, MGCL g M. persea persea, male, 17966_A11, Iran, Fars prov., Fasa area, 20 km W Estahban, 2200 m, 9–11.05.2007, MGCL accession # 2008-43 h M. persea persea, male, 17951_B02, Iran, Char Mahall-o-Bahtiyari, Umg. Shahr-e-Kord, 2000 m, 28 May 2002, leg. P. Hofmann, MGCL.

Scale bar corresponds to 10 mm in all figures. 
Photos by V. Lukhtanov    DOI: 10.3897/CompCytogen.v11i2.12370

Figure 10. Melitaea persea persea, presumptive hybrid between M. interrupta and M. persea, M. persea paphlagonia, M. higginsi, M. didyma liliputana and M. interrupta.
a Melitaea persea persea, female, 17951_B03, Iran, Esfahan, Kuh-e-Marsenan, near Zefre, 2000 m, 26 May 2002, leg. Hofmann, MGCL b presumptive hybrid female between M. interrupta and M. persea, 17966_F12, Armenia, Zhangezur Range, Megri district, Litchk, 1800 m, 23 July 1999, A. Dantchenko leg., MGCL c M. persea paphlagonia, male, 17951_F11, Iran, Khorasan, Kuh-e-Binalut, 15 km SW Zoshk, 2300–2500 m, 7 June 1999, leg. P. Hofmann, MGCL d M. persea paphlagonia, male, 17951_F11, Iran, Khorasan, Kuh-e-Binalut, 15 km SW Zoshk, 2300-2500 m, 7 June 1999, leg. P. Hofmann, MGCL e M. higginsi, male, 17966_A12, Afghanistan, Hindukush, Panchir Valley, 20 June 2004, M.J.Simon collection, MGCL f M. higginsi, female, 17950_H10, Afghanistan, Badakhshan, Mt. Yamak N of Anjuman Pass, 3500-4000 m, 1-25 July 2004 M.J.Simon collection, MGCL g M. didyma liliputana, male, 17968_E10, Israel, Mt. Hermon h M. interrupta, male, 17966_F11, Armenia Armenia, Zhangezur Range, Kadjaran, 2500 m, 21–22 July 1999, leg. A. Chuvilin, MGCL; the wing underside is with black scales along the veins.
Scale bar corresponds to 10 mm in all figures. Photos by V. Lukhtanov    DOI: 10.3897/CompCytogen.v11i2.12370

Conclusion
The Melitaea persea species complex consists of the following taxa:

• M. persea Kollar, 1849
M. persea persea Kollar, 1849 (East Turkey, Armenia, Azerbaijan, Daghestan in Russian Caucasus, western, central and nothern parts of Iran)
M. persea paphlagonia Fruhstorfer, 1917 (NE Iran, probably also S. Turkmenistan)

• M. eberti Koçak, 1980 (N. Iran)

• M. higginsi Sakai, 1978 (Afghanistan)

• M. acentria Lukhtanov sp. n. (Mt. Hermon in Israel, definitely also the neighboring territories of Syria and Lebanon)

The identity and taxonomic status of the M. persea-similar samples from north Lebanon, Jordan, Iraq, Pakistan, and Afghanistan remain still unclear. The populations from Lebanon characterized by the mitochondrial haplogroup P2 (Fig. 9) could actually represent (i) a distinct subspecies of M. persea, (ii) an undescribed subspecies of M. acentria, or even (iii) an undescribed species. Further morphological, molecular and chromosomal studies are required to select between these hypotheses.


 Vladimir A. Lukhtanov. 2017. A New Species of Melitaea from Israel, with Notes on Taxonomy, Cytogenetics, Phylogeography and Interspecific Hybridization in the Melitaea persea complex (Lepidoptera, Nymphalidae). Comparative Cytogenetics. 11(2); 325-357.  DOI: 10.3897/CompCytogen.v11i2.12370

New butterfly species discovered in Israel for the first time in 109 years http://blog.pensoft.net/2017/05/09/new-butterfly-species-discovered-in-israel-for-the-first-time-in-109-years/