Fire ants, Solenopsis invicta, dry and store insect pieces for later use

摘要

Whereas long-term storage of liquid food in the crops of worker ants and storage of dry seeds are well-known, widespread, and sometimes spectacular phenomena, there have been no previous reports documenting the storage of dead insect prey. Predacious ants typically devour their insect prey within a short time. Given a bonanza of insect prey, the fire ant, Solenopsis invicta, desiccates small pieces of these insects (creating insect "jerky") and stockpiles these pieces in its mound, immediately below the mound surface, the driest and warmest location in the nest. Feeding colonies fluorescently dyed beetle larvae, and searching for fluorescence at night under ultraviolet light illumination verified such stockpiling. Stockpiles ranged from a few pieces to hundreds. Ant larvae in field colonies fed a single dose of dyed beetle larvae remained fluorescent for about two weeks. Laboratory colonies were fed a single dose of dyed larvae and then either starved of insect food, or fed on undyed larvae. All larvae in starved colonies remained strongly fluorescent for four weeks, whereas those in fed colonies gradually declined in fluorescence, showing that in the absence of an inflow of insect prey, workers in the starved colonies fed the dried insect fragments to larvae. Storage of dried food is easily overlooked, and it is possible that it is not limited to fire ants.