Head structures A–C scanning electron micrographs of ventral view of head: A Tobochares pallidus with smooth mentum and white arrow pointing to transverse carina limiting posterior margin of antero-medial depression B Nanosaphes tricolor with top white arrow pointing to oblique crenulations of mentum, mid white arrow pointing to flat and smooth anterior surface of submentum, and bottom white arrow pointing to concave posterior surface of submentum C Quadriops reticulatus with white arrow pointing to antero-medial depression of mentum D, E light micrographs of antenna: D Aulonochares tubulus (9 antennomeres) E Chasmogenus cremnobates (8 antennomeres) F–J light micrographs of maxillary palps: F Quadriops reticulatus G Agraphydrus insidiator H Helochares sp. I Helochares lividus J Aulonochares tubulus. Scale bars: 100 μm (A–C)