Comparative susceptibility of two members of the Anopheles oswaldoi complex, An. oswaldoi and An. konderi, to infection by Plasmodium vivax

We compared the susceptibility of Anopheles oswaldoi and An. konderi to inf ection by Plasmodium vivax based on the proportion of mosquitoes presenting oocysts and sporozoites. Anophelines were captured in the State of Acre an d Rondonia, Brazilian Amazon, and used to obtain F1 progenies. After emerge nce of adults, male genitalia of mosquitoes of each family were dissected i n order to identify them as either An. oswaldoi or An. konderi. F1 progenie s of field-captured An. oswaldoi, An. konderi and An. darlingi (used as con trol) were fed simultaneously on P. vivax-infected blood. Mosquitoes were d issected on day 10-12 after feeding and examined for the presence of oocyst s and sporozoites. Both An. oswaldoi and An. konderi developed oocysts in t he midguts, however, the percentage of oocyst-positive mosquitoes for An. o swaldoi (13.8%) was higher than for An. konderi (3.3%), and only An. oswald oi developed salivary infection with sporozoites (6.9% of positivity). Infe ction rates in An. darlingi ranged from 22.5% to 30.0% for both oocysts and sporozoites. These results indicate that An. oswaldoi can transmit P, viva x: and suggest that it is more susceptible than An. konderi. Although An. o swaldoi is an exophilic and zoophilic species, it may be involved in malari a transmission as possibly occurred in the State of Acre.