Bald-faced hornet from mid-April to early October, and reproductives were produced from mid-July through the end of November. Onset of male output usually precedes that of queen output in social wasps, however here "D. maculata" is an exception to this trend. Energy investment by workers required to produce reproductives is considerable. Newly emerged males and queens are no more functional than pupae; both depend heavily on solid prey brought in by workers, thus competing with larvae for food resources. As a result, worker quantity must remain high in order to maintain reproductive output. Workers must maintain food stores and defend the nest,
Hornet robberfly Wales. It is reliant on the availability of rabbit or cattle dung. It is a member of the robberfly family Asilidae, subfamily Asilinae and is included in the list of endangered species in the British Isles. Hornet robberfly The hornet robberfly, Asilus crabroniformis, is a species of predatory insect of the Asilidae family. Reaching more than 25 mm in body length, it is one of the largest flies in the United Kingdom. and feeds on grasshoppers, dung beetles and other flies. Unlike an actual hornet, the robberfly only has one yellow patch on its abdomen and one pair of wings.