Oral challenge experiment of Ae. aegypti ‘D2S3’ and ‘Chetumal’ with DENV2-QR94 and DENV2-Jam1409. One week post-emergence females of the D2S3 strain (Dengue2 Susceptible on 3 chromosomes strain based on an Ae. aegypti ssp. aegypti x Ae. aegypti ssp. formosus hybrid) and Chetumal strain (originating from Yucatan peninsula, Mexico) received artificial bloodmeals containing ~107 pfu/ml DENV2-QR94 (American genotype DENV2 from Quintana Roo, Mexico) or DENV2-Jam1409 (American-Asian genotype DENV2 from Jamaica as control). Viruses had been propagated for 12–14 days in C6/36 cells. Artificial bloodmeals consisted of infected C6/36 cell culture supernatants mixed at a 1:1 ratio with defibrinated sheep blood. Mosquitoes were allowed to feed for 1 h. Virus titers of individual midguts and carcasses were assayed by plaque assays in LLC-MK2 (monkey kidney) cells at 14 days post-bloodmeal (pbm). Bars in the diagram represent mean values. * indicate significant difference between mean virus titers as analyzed on Y = Log(Y) transformed data by ANOVA and Bonferroni’s Multiple Comparison Test.