VARIATION WITH CASTE OF THE MANDIBULAR GLAND SECRETION IN THE LEAF-CUTTING ANT - ATTA-SEXDENS-RUBROPILOSA

In Atta sexdens rubropilosa, a strongly polyethic and polymorphic spec ies of myrmicine ant, the contents of the mandibular gland vary with c aste. Small workers of head width 0.5-1.8 mm, those generally engaged in duties inside the nest, contain chiefly 4-methyl-3-heptanone. Large r workers, those chiefly engaged in foraging, and the soldier caste co ntain a mixture dominated by neral and geranial, with very little of t he ketone of the smaller workers. The soldiers have massive glands con taining milligram amounts of neral and geranial. Virgin and mated fema les contain essentially only 4-methyl-3-heptanone, the amount increasi ng after mating, while virgin males have 4-methyl-3-heptanone and 4-me thyl-3-heptanol in approximately equal proportions. Mated males have l ess secretion and lose the 4-methyl-3-heptanol.