Morphology measures taken from A frontal; inter-ocellar distance (IOD), ocello-ocular distance (OD), median ocellus width (MOW), head width (HW), the area of seven ommatidia twice (7c), eye area front times two (EAF), total face area (TFA) B above; intertegular distance (ID) and C laterally; head area side (HAS), the area of seven ommatidia twice (7c), head depth (HD), eye area (EAS) and mesosoma length (ML). Bars are 1 mm in length. Italicised direct measures are those that were not included in the final analyses. Example species is the diurnal Hylaeus (Hylaeteron) hemirhodus (Colletidae: Hylaeinae).