The effects of corpora cardiaca on tethered flight in the Locust

Summary Removal of the cerebral neurosecretory cells tas no effect on the tethered flight pattern of adult maleLocusta. However, the flight pattern is markedly influenced by removal of the glandular lobes of the corpora cardiaca or by injection of 0.01 pair of corpora cardiaca. Changes in flight speed, brought about by such injections, may reflect differences in substrate utilisation in response to hormonal factor(s) from the corpora cardiaca. It is suggested that one effect of corpus cardiacum factor(s) may be the suppression of carbohydrate utilisation by the flight muscles.