Workers in yellow crazy ants colonies lay trophic eggs to feed larvae, queens and other subsets of the colony hierarchy. Photo by Chin-Cheng "Scotty" Yang/Kyoto University
May 23 (UPI) -- Worker ants don't typically lay eggs. But for the yellow crazy ant, worker-laid eggs are the secret sauce that keeps the colony working on overdrive.
When researchers at Kyoto University analyzed the behavior of worker ants in Anoplolepis gracilipes colonies, they found a subset of workers boast enlarged abdomens. In addition to their plethora of traditional duties, these "physogastric" workers also serve as chefs for larvae, queens and other subsets of the colony's hierarchy.
The specialized workers lay eggs for both reproduction and sustenance. Those laid for eating purposes are called "trophic eggs."
"This behavior may indicate adaptive advantages for this invasive species," researcher Chin-Cheng "Scotty" Yang said in a news release. "Production of eggs by workers for food can help the colony overcome unfavorable conditions such as shortages."
"Alternatively, if the queen dies or disappears, haploid males can be produced from reproductive eggs and then mated, offering an advantage for an orphaned colony," Yang added.
Yellow crazy ants are especially environmentally destructive. Researchers believe their findings -- detailed in the journal Frontiers in Zoology -- could help scientists develop population control strategies.
"We can now develop a strategy to combat this invasive species," said study co-author Chow-Yang Lee. "For example, if we suppress the workers' reproductive potential, it would cut off the nutrition supply for larvae and prevent colonies from growing."
Researchers are now testing a low dose of the hormonal analogue 'JHA' in ant bait. Scientists hope the hormonal additive will help curtail the reproductive abilities of the physogastric workers.