Pieris ergane (Geyer, [1828])  
Mountain Small White, Pieride de l'aethioneme, Белянка эргана, Էրգանե սպիտակաթիթեռ

Distribution and biological peculiarities in Armenia: 
The species is distributed in Southern Europe, Asia Minor, Syria, Iraq and Transcaucasia. The subspecies recorded in the Caucasus Minor and Armenia is P. e. detersa Verity, 1911. It inhabits stony parts of calcareous grasslands of Southern and South-eastern Armenia at the elevations between 1000 and 2300 m a.s.l. The only known host plant of the species from other parts of its distribution range is Aethionema saxatile, however for Armenia the host plant is not yet determined. The species gives two generations per year, when the first flies from early May to early June and second - from early July till mid August. 

Population dynamics:
The species is slightly uncommon within typical habitat, but shows stable population trend during 2003-2013 (p>0.05), most probably because its host plant that grows in the rocks and screes is not usually consumed by livestock, and therefore the species is not affected by overgrazing and uncontrolled mowing.

Conservation measures: 
The species is not included in the Global and Armenian Red Lists, as well as in CITES and Bern Conventions, but is listed in European Red Book as Least Concern. Preliminary assessment of its national conservation status suggests the same, however with a reservation of obligate monitoring, as the Mountain Small White is habitat specialist with only one host plant and therefore should be vulnerable towards habitat changes. Its current distribution range is partly covered by Zangezur Biosphere Complex, Gnishik Protected Landscape, and Khosrov Forest State Reserve. Also the species is presented in Prime Butterfly Areas Shvanidzor, Gyumorats, Kaladash, Gudemnis, Gnisheek, and Ourtsadzor. At current the species doesn't require specific conservation measures, rather than the mentioned above monitoring.

Photo: A. Danchenko