A new ant species of Megalomyrmex conducts mass raids to usurp gardens of the fungus-growing ant Cyphomyrmex longiscapus, then lives in the gardens and consumes the cultivated fungus. Unlike attine ants, however, Megalomyrmex sp. does not forage for substrate to manure the gardens; therefore, when gardens become depleted, Megalomyrmex sp. must locate and usurp new gardens. Megalomyrmex sp. workers feed their larvae with attine brood, but only after removing the fungal mycelium that covers the attine larval integument, suggesting that this fungal coat may provide partial protection against other predators. Unlike other known Megalomyrmex species, which coexist as social parasites in attine colonies, Megalomyrmex sp. expels its attine hosts during the garden raids. Megalomyrmex sp. thus maintains a unique agro-predatory lifestyle that is described here for the first time.

Summary. Nesting in abundance on stream embankments in the wet forests of Panama, the fungus-growing ant Cyphomyrmex longiscapus sensu lato has become a model organism for the study of behavior, ecology, mating frequency, cultivar specificity, pathogenesis, and social parasitism in the attine agricultural symbiosis. Allozyme markers, morphology, and other evidence indicate that C. longiscapus s.l. is in fact a complex of two species, one of which is new to science and described here as Cyphomyrmex muelleri Schultz and Solomon, new species. Although both species occur sympatrically in the same microhabitats and are ecologically, behaviorally, and morphologically quite similar, they consistently cultivate two distantly related fungal symbionts. Thus, each of the two sibling ant species is specialized on a distinct cultivar species, contradicting the conclusions of a previous study. Information is provided for reliably separating the two ant species; morphometrics, ecology, behavior, biogeography, and natural history are summarized. Possible evolutionary mechanisms underlying cryptic speciation in C. longiscapus s.l. are discussed.

The Dufour's gland of Anthophora abrupta, a solitary bee, secretes a complex mixture of liquid triglycerides containing one long-chain and two shortchain fatty acids. This is applied inside the earthen brood cells and added to the provision, where it is converted, perhaps by enzymes from the bee's saliva or gut, to solid diglycerides that are later eaten by the bee larvae. This use of Dufour's gland secretion as food and its nutritive function are reminiscent of the royal jelly secreted by honey bees.