The infection rate is the percent of all blood fed mosquitoes with DENV RNA present in their bodies. The dissemination rate is the percent of mosquitoes with infected bodies that have dengue RNA present in their legs. Treatment effects of DENV serotype, species (Ae. aegypti, Ae. albopictus), incubation period (seven and 14 days), and interactions were analyzed using maximum likelihood (ML) categorical analyses of contingency tables based on the number of individual samples categorized for the presence or absence of DENV. Separate ML ANOVA see more tests were used for body and leg samples to identify viral barriers (e.g., midgut infection and escape barriers) that may vary between treatments. Thus, each mosquito had a binomial infection status, as opposed to percentage for each replicate. Analysis of variance (ANOVA) was used to evaluate differences in DENV titers of individual mosquito bodies between DENV serotype, mosquito species, incubation periods, and interactions. If significant differences were detected, we used pair-wise contrasts of means adjusting p-values for multiple comparisons using the Bonferroni method (Sokal and Rohlf 1995). Plaque assays determined virus titers of freshly blood-fed mosquitoes were 6.8 ± 0.5 and 7.1 ± 1.2 log10 plaque-forming unit equivalents (pfue) DENV/ml for DENV-1 and DENV-2, respectively (t-test with t = 0.53, df = 11, p = 0.61). Between 10–14% of Ae. aegypti and Ae. albopictus were susceptible to infection with DENV-1 virus seven days after blood feeding and 6–10% were susceptible to infection 14 days after blood-feeding (Figure 1A). Aedes aegypti were more susceptible to infection with DENV-2 virus than Ae. albopictus (Ae. aegypti, ∼28%; Ae. albopictus, ∼9%) for both seven days and 14 days incubation periods (Figure 1B). The ML ANOVA on susceptibility to DENV infection of mosquitoes showed marginally significant effects of dengue serotype (χ2=3.79, df=1, p=0.051, Table 1) and species (χ2=3.83, df=1, p=0.050, Table 1). There was a significant interaction of mosquito species by serotype (χ2=13.2, df = 1, p=0.0003, Table 1). All other treatment effects on susceptibility to DENV infection were not significant (Table 1). To investigate the significant interaction further, we performed all possible pairwise comparisons of each species (Ae. aegypti vs Ae. albopictus) and DENV serotype (1 or 2), resulting in six comparisons. Aedes aegypti were significantly more susceptible to infection than Ae. albopictus for DENV-2 (χ2=20.14, df=1, p<0.0001) but not for DENV-1 (χ2=1.60, df=1, p=0.21). Aedes aegypti were significantly more susceptible to infection for DENV-2 than Ae. albopictus and Ae. aegypti for DENV-1 (All χ2≥13.8, df=1, p≤0.0002). All remaining comparisons on susceptibility to DENV infection were not significant (All χ2≤1.6, df=1, p≥0.21). For those mosquitoes that were susceptible to infection, between 10–20% of Ae. aegypti and Ae.