REARING OF TRIATOMA-INFESTANS KLUG (HET, REDUVIIDAE) IN THE ABSENCE OF A LIVE HOST .2. EGG-YOLK AS A DIET SUPPLEMENT

The effect of the addition of egg yolk to a blood meal on the developm ent of Triatoma infestans (Klug) was analysed. Egg yolk was added in d ifferent quantities to heparinized, citrated or defibrinated bovine bl ood, which was offered in an artificial feeder. Control groups were fe d on either non-supplemented blood or hen in vivo. Results indicated t hat the addition of egg yolk to a blood meal reduced the intermoult in terval and the moult success increased when egg yolk was added to the diet. The effect was more dramatic for the less suitable diets, as fol lows: citrated blood > defibrinated blood > heparinized blood. The min imal and most effective concentration of egg yolk in the diet was 10% When the egg yolk was centrifuged in a density-gradient, fractions wit h 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 mou lting success showed to be differentially affected by the diets and th e growth performance of in vivo-fed experimental groups could be compl etely reproduced by adding yolk to the blood diets offered in artifici al feeders.