73 (1): 129 – 152 29.4.2015 © Senckenberg Gesellschaft für Naturforschung, 2015. Transformation of head structures during the metamor- phosis of Chrysomela populi (Coleoptera: Chrysomelidae) Si-Qin Ge *, 1, Yi Hua 1, 2, Jing Ren 1, 2, Adam Ślipiński 3, Bruce Heming 4, Rolf Georg Beutel 5, Xing-Ke Yang *, 1 & Benjamin Wipfler 1 1 Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; Si-Qin Ge [
[email protected]]; Xing-Ke Yang [
[email protected]] — 2 University of Chinese Academy of Sciences, Beijing, China — 3 CSIRO Ecosystem Sciences, Australian National Insect Collection, Canberra, Australia — 4 University of Alberta, Department of Biological Sciences, Edmon- ton, Canada — 5 Entomology Group, Institut für Spezielle Zoologie and Evolutionsbiologie mit Phyletischem Museum, Friedrich-Schiller- Universität Jena, Jena, Germany — * Corresponding authors Accepted 11.iii.2015. Published online at www.senckenberg.de/arthropod-systematics on 17.iv.2015. Abstract External and internal head structures of last instar (3rd) larvae, 4th day pupae and adults of Chrysomela populi were examined using a combination of traditional and modern morphological techniques, especially µ-computed tomography and computer-based 3D reconstruction. Morphological differences and similarities between the stages were assessed. In addition to long known transformations such as the appearance of compound eyes and the reorientation of the head capsule, the adult differs from the larva by having elongated antennae and palps, a gula and anterior and dorsal tentorial arms. Additionally, several changes in the muscular system occur. Most of these cephalic transformations are related to different tasks playing a predominant role in the developmental stages: feeding in the larvae, and dispersal and mating in the adults, the latter requiring improved sensory perception.