Photo of a sheridan's hairstreak ovipositing on buckwheat (Eriogonum racemsosum).  Callophrys sheridani females seem willing to lay eggs if exposed to alternate light and dark conditions.  One day at work, I collected a sheridani during a lunch break; set her up near a light source, and then alternated placing her near that light source for 15 minutes and then placing her in a dark drawer for 15 minutes.  It seems the change of luminosity triggers movement for these butterflies.  She ended up laying roughly 20 eggs using this setup.