IBBEA   24401
INSTITUTO DE BIODIVERSIDAD Y BIOLOGIA EXPERIMENTAL Y APLICADA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Temperature dependence of standard metabolic rate in a temperate and a tropical species of triatomines
Autor/es:
ROLANDI, C.; ROMERO, B.; SCHILMAN, P.E.
Reunión:
Simposio; 8th International Symposium on the Environmental Physiology of Ectotherms and Plants; 2019
Resumen:
In tropical regions, mean temperature is higher and remains relatively constant throughout the year, contrasting with temperate regions characterized by lower mean temperatures, and higher variability on a daily and seasonal scale. Thus, ectotherms living in temperate regions could have mechanisms to cope with these thermal characteristics. Among them, the metabolic cold adaptation (MCA) hypothesis predicts that populations or species from cooler environments (high altitude or latitude) will have higher SMR or greater SMR sensitivity to temperature variations (Q10). Simultaneously, it has been hypothesized that species adapted to more variable environments will be able to modulate Q10 as a response to increasing thermal variability. Rhodnius prolixus and Triatoma infestans are haematophagous vectors of Chagas disease, with different geographical distribution across South America. We used one tropical(R. prolixus) and one temperate (T. infestans) species to test MCA hypothesis, and potential modulatory effects of a daily temperature fluctuation (DTF) to Q10. We used flow-through respirometry to measure activity and CO2 production in individual insects in real time (as a proxy for SMR) at different temperatures -rising from 10 to 35ºC by 5ºC-step-like fashion. Unfed fifth instar nymphs from both species were randomly assigned to an acclimation treatment: constant temperature (24°C), or with a DTF (17-32°C; mean = 24°C) for two weeks and they were weighed before measurements. Our results support MCA hypothesis because for temperatures above 20ºC T. infestans has a significantly (p