Fig. 4From: Comparative morphology of the postpharyngeal gland in the Philanthinae (Hymenoptera, Crabronidae) and the evolution of an antimicrobial brood protection mechanismHistological section of the postpharyngeal gland (PPG) of a female Philanthus rugosus. The epithelial cells of the upper reservoir of the PPG bear cuticular hairs reaching into the lumen of the gland. Abbreviations: ep, epithelial cells; h, hairs; lu, lumen of the upper PPG reservoir; nu, nuclei of epithelial cells. Scale bar = 25 μmBack to article page