Chemical composition of subcortical tissues of Quercus suber, the diet of the flathead oak borer Coraebus undatus (Coleoptera, Buprestidae)

Abstract

Abstract Quercus suber is severely affected by the larva of the pest beetle Coraebus undatus, which develops and forms galleries in phellogen (cork cambium) and surrounding tissues corresponding to new phellem or cork (in the outer bark) and phelloderm plus the outer phloem (inner inner bark). To better understand the nutritional requirements of C. undatus we describe twelve chemical parameters (water content, fiber, six carbohydrates, total proteins, organic matter, and lignin) of these tissues. Phelloderm plus phloem contained higher amounts of cellulose, organic matter, and sucrose than phellem, and this contained higher quantities of fiber, fructose, lignin, and moisture than phelloderm plus phloem. Samples from infected trees were richer in glucose and hemicellulose, and poorer in fiber, lignin, water, and myo-inositol than those of uninfected trees.