AOL	width between anterior and posterior ocellus, measured as minimum length in frontal view
LH	length of head, measured in antero-dorsal view, from apex of clypeus to vertex
OOL	shortest distance from a posterior ocellus to nearest eye margin
WF	width of frons, measured in antero-dorsal view, its minimum width
WH	width of frons, measured in antero-dorsal view, its minimum width
WOT	width of ocellar triangle, measured in antero-dorsal view, maximum width including ocelli
DPV	distance between posterior ocelli and vertex crest in antero-dorsal view