Age-specific mortality analysis of the dry forest kissing bug, Rhodnius neglectus

RABINOVICH, J. E.; NIEVES, E. L.; CHAVES, F.

ENTOMOLOGIA EXPERIMENTALIS ET APPLICATA

WILEY-BLACKWELL PUBLISHING, INC

Año: 2010 vol. 135 p. 252 - 262

0013-8703

Age-specific mortality patterns can be very different across insects with different life histories. Someholometabolous insects (like mosquitoes, fruit flies) show a pattern where mortality rate deceleratesat older ages, whereas other holometabolous insects (bruchid beetles) and hemimetabolous insects(cotton stainers, milkweed bugs, and kissing bugs) show an age-specific mortality pattern thatincreases through all ages. Kissing bugs are strictly hematophagous and are vectors of Trypanosomacruzi Chagas, the etiologic agent of Chagas disease. Here, we tested whether cohort data from the dryforest kissing bug, Rhodnius neglectus Lent (Hemiptera: Reduviidae), supports an increase of mortalityrate that decelerates with age. We analyzed the age-specific mortality pattern of a cohort of 250individuals of R. neglectus. We used a suite of seven models with different degrees of complexity, tomodel age-dependent forms of change in mortality rate increase in R. neglectus in the laboratory.Weused the Akaike model selection criterion to choose between models that consider absence or presenceof mortality deceleration. Five of the seven models (logistic, Gavrilovs, Gompertz, DeMoivre,and exponential) showed a statistically significant fit to the mortality rate. Weak late-age mortalitydeceleration in R. neglectus was supported by the best fit (logistic model), and this result is consistentwith predictions of the disposable soma theory of senescence.