Award Date

2009

Degree Type

Dissertation

Degree Name

Doctor of Philosophy in Biological Sciences

Department

Life Sciences

Advisor 1

Stephen Roberts, Committee Chair

First Committee Member

Carl Reiber

Second Committee Member

Michelle Elekonich

Third Committee Member

Paul Schulte

Graduate Faculty Representative

John Mercer

Number of Pages

93

Abstract

In honey bees, the capacity for flight underlies many behaviors which impact fitness and longevity, such as the ability to forage or evade predators. However, flight capacity is not fixed across bees' lifespan, which is punctuated by a suite of physiological changes that accompany age and the transition from in-hive to foraging behaviors; thus, flight capacity may vary during periods of development, senescence, or in response to morphological damage such as wing wear. This dissertation describes the biomechanics and aerodynamics which contribute to the scope of honey bee flight performance, and investigates how age, behavioral development, and wing-wear affects flight kinematics and maximal flight capacity. Three experiments were performed using high-speed (4347-6000 fps) digital videography and variable-density atmospheres, ranging from air (79%N 2 , 21%O 2 ; 1.41 kg m -3 ) to heliox (79%He, 21%O 2 ; 0.41 kg m -3 ): (1) the detailed kinematics of honey bee foragers during hovering in air, performing simple enhanced-lift maneuvers, and hovering in heliox were compared; (2) I investigated the effects of age and behavioral development on the kinematics and flight capacity of honey bee nurses and foragers; (3) I investigated the effects of symmetric and asymmetric experimental wing wear on the kinematics and flight capacity of honey bee foragers. Mature foragers vary aerodynamic force production almost exclusively by modulating wing stroke amplitude and holding wingbeat frequency constant, which yields greater wing angular velocities. Young (precocious) foragers and over-aged foragers increase stroke amplitude when challenged, however they are unable to maintain wingbeat frequency. Thus, their maximal flight capacity is impaired due to decreased wing angular velocity, relative to typical-aged foragers. Nurse bees demonstrate impaired kinematics similar to young foragers, but they are constrained by heavier body masses which further limits maximal flight capacity. Bees maintained robust flight in air in response to loss of wing area (wing wear), however maximum wingtip velocity and maximal flight capacity decreased in direct proportion to wing area. Bees with asymmetric wear produced lower maximum wingtip velocity than non-worn and symmetrically-worn groups, and despite less total wing area loss than the symmetric group, asymmetric wear caused a greater impairment in maximal flight capacity.

Keywords

Aerodynamics; Apis mellifera; Biomechanics; Flight; Honeybees; Natural; Hovering

Disciplines

Entomology

Language

English


Included in

Entomology Commons

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