Insect aerodynamics: vertical sustaining force in near-hovering flight

The source of vertical sustaining force for large insects capable of near-hovering flight is unclear. Induced velocities of a simulation of the insect Melolontha vulgaris in forward flight were measured with a hot-wire anemometer. The results were negative with respect to the drag concept of vertical force, but provided certain support for the circulation concept. Unsteady effects (the effects of variant air velocity) proved significant.