Development of the thoracic muscle and flight behaviour of Glossina morsitans orientalis Vanderplank

Abstract

Laboratory and field studies were made to study the flight behaviour and development of thoracic musculature in male Glossina morsitans orientalis Vanderplank collected as adults near Kariba, Rhodesia, or emerged from puparia collected there. Muscular development, measured as thoracic residual dry weight, was significantly inhibited by confinement in the laboratory and flight activity declined when laboratory-emerged flies were maintained in the laboratory. Survival of laboratory-emerged flies in the field was only 17% that of field-emerged flies. Irreversible behavioural and physiological inhibition in flight and in flight musculature is therefore believed to occur within the first few hours of adult life as a result of confinement; 70–80% of the confined population was affected. These inhibitions can be avoided by using field-emerged adults for field trials.