Leaf beetle hind wing (Chrysomela populi Linnaeus), with landmark locations (the dot with number), vein nomenclature and regional division. The nomenclature of the wing venation follows that of Kukalová-Peck & Lawrence (1993, 2004). Radial area: green, central area: blue, medial area: purple, anal area: yellow, apical (folding) area: red. Proximal part landmarks 1–6, 23, 24, and 26–36 mainly include radial, medial, and anal areas; distal part landmarks 7–22 and 25 include the central area, radial cell, and apical area. Abbreviations: Costa (C), Subcosta (Sc), Subcosta Anterior (ScA), Subcosta Posterior (ScP), Radius Anterior (RA), Radius Posterior (RP), Radial cross veins (r3, r4), Media Posterior (MP), Radio-medial cross veins (rp-mp1, rp-mp2), medial cross vein (cv), Cubitus Anterior (CuA), Medio-cubital Cross-vein or Arculus (mp-cua), Anal Anterior (AA), Anal posterior (AP). “+” indicates fused veins. The sub-number of veins reflects vein branches.