Bald-faced hornet to laying eggs while the workers take over all other necessary housekeeping tasks. At some point, sometime before the midpoint of colony life, the colony will begin to invest energy in producing reproductives as well. This marks the transition into the reproductive stage. There is an extensive time period where both workers and reproductives are raised. Production of both castes limits the size of the work force. However, an early switching time is highly adaptive for social wasp colonies in limiting the risk of total loss. In a sampling of 50 colonies taken in Maryland in 1977, workers were produced
Asian hornet Asian hornet The Asian hornet, also known as the yellow-legged hornet ("Vespa velutina"), is a species of hornet indigenous to Southeast Asia. It is of concern as an invasive species in some other countries. "Vespa velutina" is slightly smaller than the European hornet. Typically queens are 30 mm in length, and males about 24 mm. Workers measure about 20 mm in length. The species has distinctive yellow tarsi (legs). The thorax is a velvety brown or black with a brown abdomen. Each abdominal segment has a narrow posterior yellow border, except for the fourth segment, which is orange. The head