Feeding cycles and flight activity in field populations of tsetse (Diptera:Glossinidae)

Abstract

AbstractPublished laboratory measurements of the levels of fat and haematin inGlossinafollowing a blood-meal were used to develop a prediction of the relationship between fat and haematin during the course of the feeding cycle. The fat-haematin relationship appears to be nearly linear over the later part of the feeding cycle. Data from three field studies onG. morsitansWestw.,G. swynnertoniAust. andG. fuscipesNewst. were analysed in the way suggested by the prediction, and the observed rates of fat depletion were used to estimate flight activity of male flies towards the end of each feeding cycle. Results forG. palpalis(R.–D.) andG. tachinoidesWestw., obtained in other studies with new electric sampling devices as well as by men with hand nets, illustrated particularly clearly the fat-haematin relationship over the whole of the feeding cycle. This was made possible by the electric traps catching more flies nearer to the start of their feeding cycle than the men with hand nets. A comparison between the different areas suggested that the fat level may trigger the onset of feeding behaviour inGlossina.