C. tenellus may refer to one of the following species:
Catharylla tenellus, a moth species Circulifer tenellus, the beet leafhopper, a leafhopper species Cleptometopus tenellus, a beetle species Cyanococcus tenellus, a synonym for Vaccinium tenellum, the small black blueberry Cyperus tenellus, tiny flatsedge, a plant species