An experimental study on the detection of fructose in Aedes aegypti.

Male and female Aedes aegypti fed a 10% sucrose solution and/or blood were tested to determine the duration of fructose detection in their bodies and the volume of sugar solution they ingested. The limit of detection of fructose by the cold anthrone test was investigated in a series of experiments. Results were applied to the interpretation of sugar feeding by Ae. aegypti collected inside houses in Puerto Rico during times of low (cool season) and high (hot season) dengue transmission in 1996. We conclude that, under our experimental conditions, the cold anthrone test can detect a 10% sucrose solution in male and female Ae. aegypti up to approximately 4 days after ingestion, even the smallest volumes of 10% sucrose solution ingested by experimental mosquitoes are detectable, the test is sensitive enough to detect 0.6 microgram of fructose, and the cutoff point for defining positive fructose values in field-collected females should be based on blood-engorged specimens. We confirmed that female Ae. aegypti collected from natural resting sites inside houses in Puerto Rico seldom, compared to males, contain detectable amounts of fructose.