Host plants variably support Ae. aegypti survival, fecundity, and egg viability
In Experiment I, survival of Ae. aegypti females provided with an initial bloodmeal and fed on the different diets was significantly different (Log rank = 40.785, df = 2, p < 0.001; Fig. 1A); those fed on glucose solution, P. dulce and blood having mean survival of 23.5 ± 0.6, 17.7 ± 0.7 and 16.1 ± 0.7 days, respectively. With no initial bloodmeal, the mean survival of female Ae. aegypti on glucose and P. dulce were 23.6 ± 0.8 and 13.1 ± 0.8 days, respectively (Log rank = 48.04, df = 1, p < 0.001; Fig. 1B). Similar survival patterns were observed in males, with those fed on glucose having a mean survival of 21.6 ± 0.7 days while those fed on P. dulce had a median survival of 14.6 ± 0.7 days (Log rank = 25.162, df = 1, p < 0.001; Fig. 1C).
In Experiment II, survival of Ae. aegypti females provided with an initial bloodmeal and fed on the different diets was significantly different (Log rank = 419.727, df = 3, P-value < 0.001; Fig. 1D), with mean survival of 24.0 ± 0.6, 17.0 ± 0.4, 7.2 ± 0.4 and 16.1 ± 0.8 days among glucose, L. nepetifolia, O. ficus-indica and blood, respectively. With no initial bloodmeal, the mean survivals on glucose solution, L. nepetifolia and O. ficus-indica were 23.9 ± 0.7, 25.2 ± 0.5 and 7.4 ± 0.2 days for females (Log rank = 485.405, df = 2, P-value < 0.001; Fig. 1E) and 21.0 ± 0.6, 14.5 ± 0.5 and 6.5 ± 0.4 days for males (Log rank = 354.639, df = 2, P-value < 0.001; Fig. 1F), respectively.
For fecundity, females fed on P. dulce and glucose laid 1.6- and 2.2-fold less eggs, respectively, than those fed exclusively on blood but no significant difference was detected (F(2, 267) = 1.985, I = 0.139; Fig. 2A). On the other hand, those fed on L. nepetifolia laid 1.6-fold more eggs than those fed exclusively on blood, while mosquitoes fed on O. ficus-indica and glucose had 1.7- and 2-fold less eggs than those fed exclusively on bloodmeal, respectively (F(3, 356) = 3.495, p = 0.0158, Fig. 2B). Besides having the highest fecundity rate, mosquitoes fed on L. nepetifolia had a sustained moderate oviposition throughout the experimental period which was comparable to those that exclusively fed on bloodmeal (Fig. 2C and D).
Regarding egg viability, significant differences were detected in the hatching rates of eggs laid by mosquitoes fed on glucose (30%), P. dulce (29%) and blood (59%) (F(2, 31) = 3.344, p = 0.0484; Fig. 3A). Similarly, a significant difference was detected in hatching rates of eggs from Experiment II (F(3,40) = 3.268, p = 0.31); with hatching rates of 42%, 34%, 12% and 60% for eggs from females fed on glucose, L. nepetifolia, O. ficus-indica and bloodmeal, respectively, (Fig. 3B).
Variable amino acid quality support observed differences in the fitness matrix of Ae. aegypti fed on different host plants
A total of 12 amino acids present in mice blood were detected in variable amounts in the sap plus nectar of three plant species. These included valine, serine, glutamine, proline, glycine, methionine, tyrosine, isoleucine, leucine, phenylalanine, tryptophan, and arginine. Uniquely abundant amino acids detected in the guts of mosquitoes fed on the nutrient regimes included valine, arginine, isoleucine, methionine, and phenylalanine (Fig. 4A). Valine was 5-, 13- and 14-fold more abundant in the guts of mosquitoes fed on L. nepetifolia, glucose and O. ficus-indica, respectively. In addition, arginine was abundant in the guts of those fed on O. ficus-indica, isoleucine in those fed on P. dulce, and methionine in those fed on L. nepetifolia (Fig. 4B). On the other hand, phenylalanine was 6-, 8- and 11-fold less abundant in the guts of mosquitoes fed on P. dulce, O. ficus-indica and glucose solution, respectively, relative to those exclusively fed on blood (Fig. 4B). Notably, glutamic acid was present in the guts of mosquitoes fed on mice blood but absent in those from all the other diets. To further confirm that female Ae. aegypti indeed were able to imbibe these amino acids from their host plants, we analyzed for four of the identified amino acids in the guts of non-blood fed mosquitoes. Besides valine, none of the females from glucose diet had any detectable amino acids in their guts. However, females fed on all the three host plants had variable amounts of methionine, isoleucine, phenylalanine, and arginine in their guts (Fig. 4C).