Conservative harvest habit by harvester ants exploiting fields of bread wheat

Harvester ants are common and very efficient granivores in many regions of the world. The ants may collect dispersed seeds from the ground or climb on plants to harvest seeds. While collecting or harvesting wild cereal seeds they first trim the long and bulky awns to allow better seed transportation to their nests and through the narrow passages inside their nests. In domesticated free-threshing cereals, flower parts including awns are not adhered to the seeds as in wild-type cereals and cutting open the loose glumes is sufficient to free the seeds. However, when various harvester ant (Messorspp.) species climb on domesticated free-threshing bread wheat in agricultural fields to harvest seeds they keep their ancient habit of beginning harvest by awn trimming of wild-types in spite of the fact that it is not necessary in the domesticated ones. We show and discuss their conservative harvest behavior.