Aedes aegypti and Aedes albopictus females feed both on blood and on sugar, whereas males ingest only sugar, mostly fructose. Sugar ingestion pattern of mosquitoes has been shown to be a relevant parameter that affects their vector capability. The objective of this study was to evaluate the feeding pattern of these two species in Rio de Janeiro. The Anthrone test has been used to quantify fructose in field mosquitoes and some authors claim that A. aegypti females rarely feed on sugars. There is a contradiction between the recent literature and classic publications in concern to Anthrone’s detection limit. To clarify this point we repeated these experiments and found its detection limit to be 12mg of fructose, agreeing with classic publications. As we confirm that this method is not enough sensitive to detect sugar in single mosquitoes, it was abandoned.  Therefore, to achieve the objective of this study, we searched for a new and more practical methodology to quantify fructose in mosquitoes. The Selliwanoff method showed to be appropriate for this purpose.  This reaction has a detection limit of 2.5mg of fructose (5 times more sensitive than Anthrone) and seemed to be suitable to measure the sugar intake by individual mosquitoes. This method was shown to be reliable and suitable to crude mosquito homogenates. Because of the size difference, males and females of both species were separately tested. The sugar intake by females was found to be higher than that of males in both species. Likewise, sugar intake by A. albopictus females was found to be higher than that of A. aegypti. A. aegypti 8 days old was found ingesting 1,8 times more sugar than 3 days old. Most of the individuals tested after 24 hours fasting were negative for fructose, as measured by the Selliwanoff test.