Odonatological Abstracts

(7578) BYERS, J.R., 1975. Tyndall blue and surface white of tent caterpillars, Malacosoma spp, J. Insect Physiol. 21: 401-415. — (Author’s current address unknown). Tyndall scattering occurs when a beam of white light encounters very small transparent particles whose properties differ from those of the surrounding medium. If the particles have dimensions about equal to or somewhat less than the wavelength of blue light (i.e. about 400 nm), they will reflect, or scatter, more of the short-wave than of the long-wave components of white light. In Odon. blue colours are usually due to Tyndall-active particles within the subcuticular epidermis. If the particles are underlain by a layer of dark pigment the reflected light is blue, but if the pigment is yellow, the reflected light appears green. The situation in the genera Diphlebia, Austrolestes, Enallagma, Erythemis and Libellula is stated.