Rearing of Triatoma infestans Klug (Het., Reduviidae) in the absence of a live host. II. Egg yolk as a diet supplement

Abstract

Abstract: The effect of the addition of egg yolk to a blood meal on the development of Triatoma infestans (Klug) was analysed. Egg yolk was added in different quantities to heparinized, citrated or defibrinated bovine blood, which was offered in an artificial feeder. Control groups were fed on either non‐supplemented blood or hen in vivo. Results indicated that the addition of egg yolk to a blood meal reduced the intermoult interval and the moult success increased when egg yolk was added to the diet. The effect was more dramatic for the less suitable diets, as follows: citrated blood > defibrinated blood > heparinized blood. The minimal and most effective concentration of egg yolk in the diet was 10% v/v. When the egg yolk was centrifuged in a density‐gradient, fractions with different performance could be obtained; middleweight fractions, but not the heaviest or lightest ones reproduced the observed effects of the whole yolk at the corresponding concentration. Growth rate and moulting success showed to be differentially affected by the diets and the growth performance of in vivo‐fed experimental groups could be completely reproduced by adding yolk to the blood diets offered in artificial feeders.