Ulster County Silvery Blues

[Steve M. Chorvas]

Town of Saugerties

On 25 April, I encountered 6-8 fresh male Silvery Blues flying in a small patch of limestone quarry in the Town of Saugerties, extreme northern Ulster County.  By 30 April, there were at least 15+ individuals flying in the same small area, including males, females ovipositing on the flower buds of Sweet Clover, and a mated pair. 

I typically find Silvery Blue flying late May through the middle of June in meadow habitat, a few miles north in Greene County, where they oviposit on Cow Vetch.  Given the relatively early April date, atypical habitat, and host plant selection, I considered the possibility of the southern race (lygdomus) at the Ulster County site.  

The southern subspecies apparently once flew on shale barrens in New York State, but has long since retracted their range south.  Am I correct in assuming the use of Sweet Clover as a host plant rules out the southern subspecies?  I would appreciate any thoughts. 

Steve

Steve M. Chorvas

Saugerties, NY 

Silvery Blue, Town of Saugerties - 30 April 2025