FEEDING RESPONSE OF THE HEMATOPHAGOUS BUGS RHODNIUS-PROLIXUS AND TRIATOMA-INFESTANS TO SALINE SOLUTIONS - A COMPARATIVE-STUDY

A comparative study of the intake response to saline solutions was mad e in Rhodnius prolixus and Triatoma infestans by examining the effects of saline concentration and starvation period. Both species imbibed a 0.15 M NaCl solution in the absence of phagostimulants. Whereas third -instar larvae of T. infestans starved for 1 week since ecdysis ingest ed large quantities of saline, R. prolixus of the same stadium did the same only after a food deprivation time of between 8 and 16 weeks sin ce ecdysis. Interspecific differences could be ascribed to distinct sa line acceptance thresholds for the same food deprivation period. These differences are discussed in relation to the different ecological nic hes occupied by each species. Some features of the physiological mecha nism related to saline solution response are also discussed.