Comparative kinetics of bloodmeal intake by Triatoma infestans and Rhodnius prolixus, the two principal vectors of Chagas disease.
Chagas disease vector insects Triatoma infestans and Rhodnius prolixus (fifteen stage III nymphs per 4 litre cage) were allowed to feed on anaesthetized mice for 1 h (control group), or on active non-anaesthetized mice (NAM) for 2, 4 or 8 h exposure. The bloodmeal size (weight increase) for both species was proportional to the duration of contact with NAM, due to ingestion of multiple small bloodmeals, up to 142% of control weight for T. infestans with 8 h exposure to NAM. The mean weight increase of T. infestans nymphs after 4 h contact with NAM was similar to that of the control group, whereas for R. prolixus, 8 h contact with NAM gave only 64% of the control value. For both species of insect, within 4 h of feeding, > 20% of the bloodmeal weight was lost by defaecation and diuresis. The proportions of unfed nymphs and mortality during 2 h contact with NAM were significantly higher for R. prolixus, demonstrating better exploitation of the host blood source by T. infestans, apparently because during blood-feeding the latter insect species caused less irritation to the host.
Pereira
H
H
UNIFENAS, Alfenas, Brazil.
Penido
C M
CM
Martins
M S
MS
Diotaiuti
L
L
D000818:Animals; D001835:Body Weight; D014355:Chagas Disease; D005247:Feeding Behavior; D006790:Host-Parasite Interactions; D006801:Humans; D007303:Insect Vectors; D051379:Mice; D011156:Population Density; D012239:Rhodnius / Q000469:parasitology*; D014224:Triatoma / Q000469:parasitology*