Host blood source was found to affect both the development and the reproductive performance of Rhodnius prolixus. The insects were reared on citrated human, rabbit, chicken, sheep and horse blood sources, through a membrane feeder, during an entire life cycle, from eggs to adults. Development and reproduction in terms of the number of unfed insects, number of moulting, mortality intermoulting period, number of egg/female, conversion of blood into egg (mg meal/egg) and percentage of hatch as effective physiological parameters were investigated. Our results showed that human or rabbit blood meals were more nutritionally efficient than the other blood samples used because (i) the insects developed faster, presented low mortality and about 80% of them reached the adult stage; and (ii) females oviposited an average of at least 100% more eggs. The inefficiency of chicken and horse blood sources as diets for R. prolixus was manifested in (i) a decrease of the amount of ingested blood and (ii) only a reasonable nutritional quality. The inadequacy of sheep blood was observed by a mortality extremely high, poor moulting response and drastic reduction in egg production.

A alimentação de ninfas e adultos de Rhodnius prolixus em camundongos tratados previamente com ivermectin (0,2 mg/kg peso corporal, via subcutânea) resultou em alta mortalidade dos insetos. Este efeito foi mais drástico em ninfas de 1º e 2º estádios. Foi observado que as ninfas de 3º estádio alimentadas 24-48 horas após o tratamento dos camundongos demonstraram uma mortalidade maior do que os insetos alimentados 72 horas após o tratamento. Os insetos de 3º estádio sobreviventes aos tratamentos apresentaram uma inibição total das mudas. Fêmeas adultas alimentadas em camundongos 24 horas após o tratamento com invermectin demonstraram uma considerável redução na produção de ovos. Este efeito não foi revertido por uma posterior alimentação em camundongos normais. Foi sugerido que dose subletal de ivermectin poderia interferir no controle neuro-endócrino do desenvolvimento e reprodução do inseto.

Ivermectin (0.2 mg/kg body weight) caused a high mortality in nymphs and adults of Rhodnius prolixus following a single meal in mice sub-cutaneously injected with the drug. This effect was more evident in nymphs of 1st-and 2nd-instar than in older nymphs and adults. Third-instar nymphs presented a high mortality when fed on mice treated with ivermectin 24 and 48 hours previously, while mortality was significantly reduced in nymphs fed on mice treated 72 hours before. Surviving 3rd-instar nymphs did not molt. When adult females were fed once on mice treated for 24 hours with ivermectin there was a considerable reduction in egg production. This inhibition was not reversed by a second feeding on normal mice. We concluded that sub-lethal doses of ivermectin caused toxic effects interfering in the neuro-endocrine control of development and reproduction of this bloodsucking insect.