Benzoquinones from scent glands of phalangiid harvestmen (Arachnida, Opiliones, Eupnoi): a lesson from Rilaena triangularis

The Author(s) 2014. This article is published with open access at Springerlink.com Abstract In case of disturbance, the phalangiine har-vestman Rilaena triangularis (Eupnoi, Phalangiidae) emits a directed jet from large prosomal scent (‘‘defensive’’) glands. The pungent-smelling secretion was analyzed by gas chromatography–mass spectrometry and found to contain mainly 1,4-benzoquinone along with 1,4-naphtho-quinone and caprylic (=octanoic) acid. While various alkylated benzoquinones are characteristic for the scent gland secretions of many grassatorean Laniatores, this is the first incidence of benzoquinone-based chemical defense in palpatorean harvestmen