Vespa velutina nigrithorax A basal area of the right mandible, showing the absence of pits B left half of the labrum in ventrofrontal view C lateral part of the labrum showing spicules on the palate (arrow) D, E head in frontal view, with the arrow indicating a dotted patch (dt) and an enlarged image F labrum (left) and palate (right) in frontal view G apical portion of the right mandible, with the arrow showing variations in the shape of teeth I and II. Scale bars: 0.03 mm (A, C); 0.1mm (B, F, G); 0.3 mm (D, E).