Alkylphenols in the defensive secretion of the nearctic opilionid,Stygnomma spinifera (Arachnida: Opiliones)

Abstract
The opilionid,Stygnomma spinifera, secretes from a pair of exocrine glands on the cephalothorax between the first and second pair of legs a major volatile component, 2-methyl-5-ethylphenol, and two minor components, 2,3-dimethylphenol and 2,3-dimethyl-5-ethylphenol. These alkylphenols are constituents of a defensive secretion and repel ants, a natural predator of opilionids. The probable significance of this secretion in the biology ofS. spinifera and in the defensive strategies of opilionids in general is discussed.