Seed harvester ants (Pogonomyrmex rugosus) as “pulse” predators

Seed harvesting ants, Pogonomyrmex rugosus, collected grass cicadas at a high rate (>5 min−1 taken into the nest) at one location where cicada emergence exceeded 3 m−2. Dry conditions in the winter-spring resulted in no annual plants in the northern Chihuahuan Desert. P. rugosus colonies were inactive in areas where grass cicada emergence was less than 1 m−2. P. rugosus initiate intense predatory activity in response to pulse of large numbers of prey. This study demonstrates that predatory behavior of seed harvesting ants is not limited to incidental encounters with prey during seed harvesting activities. Pulse predation demonstrates the importance of protein to seed harvester ant colonies.