thecla

from The Century Dictionary.

• noun A large and important genus of butterflies, containing the forms commonly known as hair-streaks, typical of the subfamily Theclinæ of the Lycænidæ.
• noun An insect of this genus.

from the GNU version of the Collaborative International Dictionary of English.

• noun Any one of many species of small delicately colored butterflies belonging to Thecla and allied genera; -- called also hairstreak, and elfin.