Fig 1.
Graphical representation of the biological events occurring in the Aedes aegypti female life-cycle at optimal (A) and lower (B) temperatures in relation with the dengue and chikungunya virus infections, amplification and transmission.
GC = Gonotrophic Cycle, EIP = Extrinsic Incubation period.
Fig 2.
Evolution of the parity rates of Aedes aegypti females in time under laboratory conditions at mean constant temperatures of 24°C, 27°C and 30°C.
(A) Parity rates after the blood meal was taken at day 0. (B) Temperature threshold to complete the gonotrophic cycle.
Table 1.
Tukey-type test results for comparison among proportion of blood feeding females, parity rate of blood-engorged females, overall parity rates, survival at 25 days of age, proportion of females having 2 GCs and the proportion of females having 3 GCs, at the different experimental temperatures.
Fig 3.
Mean duration and standard errors of the gonotrophic cycles (GCs) at the experimental temperatures of 24°C, 27°C and 30°C.
GC1: first gonotrophic cycle, GC2: second gonotrophic cycle, GC3: third gonotrophic cycle.
Table 2.
Mann-Whitney non-parametric results for the durations of the gonotrophic cycles versus the age of the females at the different temperatures.
Fig 4.
Linear regression representing the mean durations of the Gonotrophic Cycles as a function of temperatures (y = −0.4998x + 20.368, r2 = 0.98).
Fig 5.
Mean numbers of eggs per female and per gonotrophic cycle at the different experimental temperatures of 24°C, 27°C and 30°C.
GC1: first gonotrophic cycle, GC2: second gonotrophic cycle, GC3: third gonotrophic cycle.
Fig 6.
Survival of females of Aedes aegypti in laboratory conditions at constant temperatures of 24°C, 27°C and 30°C plotted against the age of females.
Fig 7.
Probability of daily survival of females of Aedes aegypti in laboratory conditions at constant temperatures of 24°C, 27°C and 30°C plotted against the age.
Fig 8.
Expectation of infective life (Ii) in days for 50% of the females of Aedes aegypti females according to the EIP at constant temperatures of 24°C, 27°C and 30°C, plotted against the parity rates.
Fig 9.
Histological pictures (x40) from binocular loupe observation of the ovaries of selected females of Aedes aegypti during the gonotrophic cycle at 24°C.
Before the first blood meal when the female is nulliparous (A), 3 days after the blood meal when eggs are forming (B), about 8 days after the blood meal when the female is gravid and ready to lay the eggs (C) and after the second blood meal when the female is parous and the second batch of eggs in formation (D). Scale bars, 0.25 mm.
Table 3.
Expectations of life (in days) and expectations of infective life (in days) for An. gambiae and for Ae. aegypti from the parity rates.