Effect of feeding frequencies on the reproductive efficiency for two species of Triatoma of different epidemiological importance

Abstract

Introduction: In Triatominae, reproductive efficiency is an important factor influencing population dynamics, and a useful parameter in measuring a species' epidemiological significance as a vector of Trypanosoma cruzi (Chagas,1909).The reproductive efficiency of triatomines is affected by food availability; hence, we measured and compared the effects of feeding frequencyon the reproductive parameters of Triatoma patagonica (Del Ponte, 1929) and Triatoma infestans (Klug, 1934), and the effects of starvation on T. patagonica. Methods: Couples from both species were fed weekly, or every 3 weeks; in addition, femalesin couples of T. patagonica were not fed. Each couple was observed weekly and reproductive efficiency was assessed on the following parameters: fecundity(eggs/female),fertility (eggs hatched/eggs laid), initiation and end of oviposition, initiation of mating,number of matings/week, and number of reproductive weeks. Relative meal size index (RMS), blood consumption index (CI), and E values (eggs/mg blood) were also calculated. Results: Changes in feeding frequency affected the reproductive parameters of T. patagonica only, with a decrease in fecundity and number of reproductive weeks forthosefedevery 3 weeks,or not fed. The reproductive period, RMS index, and CI were lower for T. patagonicathan T. infestans. However, despite the lower fecundity of T. patagonica,this species required less blood to produce eggs, with an E-value of 2 compared to 2.94 for T. infestans. Conclusions: Our results suggest thatthe differences in fecundity observed between species reflect the availability of food in their natural ecotopes.