Published online by Cambridge University Press: 14 March 2018
The covering wings (elytra) in the Colorado potato beetle Leptinotarsa decemlineata appear shiny, smooth, water-repellent, and slightly slippery, (Fig. 1). These properties are due to the presence of epicuticle, the outermost layer of the insect integument, covered by a wax-like lipid surface layer called grease. Surface waxes have been previously reported in a variety of conditions, from liquid viscous coatings to crystalline structures in form of plates, rods and filaments from many insects (adults and larvae) and arachnids (Hadley, 1981a,b). Beament (1945) and Wigglesworth (1945) considered an outer thin layer of solid wax, whereas Lewis (1962) rather assumed an oil film on the epicuticle surface to be widespread throughout insects.