Vital Statistics of Triatominae (Hemiptera: Reduviidae) Under Laboratory Conditions: III. Rhodnius neglectus

Five cohorts of 100 eggs of Rhodnius neglectus Lent 1954 (Hemiptera Reduviidae) were reared simultaneously in the laboratory under constant conditions (26 +/- 1 degrees C and 60 +/- 10% RH), with mortality and fecundity data recorded weekly. We calculated stage-specific developmental times, age-specific mortality and fecundity, stage-specific and total preadult mortality, and the intrinsic rate of natural increase (r0 = 0.21), the finite population growth rate (h = 1.23), the net reproductive rate (R0 = 314.24), and the generation time (T = 21.45 wk). Elasticity analysis showed that the dominant life-history traits determining lamda were the adult female survival, and the survival of instar V nymphs (molting into adult females). Adult females dominated the stage-specific reproductive value, and the egg stage dominated the stable stage distribution (SSD). The damping ratio (p = 1.11) suggests a relatively rapid period of recovery to a disturbed SSD. Results were compared with previous values from the literature and conform relatively well, considering that environmental conditions were not always the same. Compared with two other species of the same genus, Rhodnius neivai Lent 1953 and Rhodnius prolixus Stål 1859, R. neglectus ranked higher in fecundity (total eggs/ female /life) and in female longevity, intermediate in the intrinsic rate of natural increase (r0), and lower in developmental time and mortality. By fitting a logistic model of population growth to the density field values of a spontaneous colonization of two field experimental chicken coops we estimated the intrinsic rate of natural increase and carrying capacity parameters, and compared the former with our laboratory results.