Influence of Temperature on the Life-Cycle Dynamics of Aedes albopictus Population Established at Temperate Latitudes: A Laboratory Experiment

Abstract

The mosquito species Aedes albopictus has successfully colonized many areas at temperate latitudes, representing a major public health concern. As mosquito bionomics is critically affected by temperature, we experimentally investigated the influence of different constant rearing temperatures (10, 15, 25, and 30 °C) on the survival rates, fecundity, and developmental times of different life stages of Ae. albopictus using a laboratory colony established from specimens collected in northern Italy. We compared our results with previously published data obtained with subtropical populations. We found that temperate Ae. albopictus immature stages are better adapted to colder temperatures: temperate larvae were able to develop even at 10 °C and at 15 °C, larval survivorship was comparable to the one observed at warmer conditions. Nonetheless, at these lower temperatures, we did not observe any blood-feeding activity. Adult longevity and fecundity were substantially greater at 25 °C with respect to the other tested temperatures. Our findings highlight the ability of Ae. albopictus to quickly adapt to colder environments and provide new important insights on the bionomics of this species at temperate latitudes.

Keywords: invasive species; mosquito bionomics; mosquito dynamics.

Figure A1

Estimated posterior distributions of Λ_E(T), the average length of time (days) between immersion of eggs in water and hatching response at 15, 25, and 30 °C. Dashed black lines represent the 2.5 and 97.5 quantiles. Solid red lines represent the average value for subtropical Ae. albopictus.

Figure A2

Estimated posterior distributions of P_E(T), the egg hatching rate at 10, 15, 25, and 30 °C. Dashed black lines represent the 2.5 and 97.5 quantiles. Solid red lines represent the average value for subtropical Ae. albopictus.

Figure A3

Estimated posterior distributions of Λ_L1-A(T), the average duration (days) of development from L1 to A at 15, 25, and 30 °C. Dashed black lines represent the 2.5 and 97.5 quantiles. Solid red lines represent the average value for subtropical Ae. albopictus.

Figure A4

Estimated posterior distributions of P_L1-A(T), the survival rate from L1 to A at 15, 25, and 30 °C. Dashed black lines represent the 2.5 and 97.5 quantiles. Solid red lines represent the average value for subtropical Ae. albopictus.

Figure A5

Estimated posterior distributions of Λ_A(T), the average adult female longevity (days) at 10, 15, 25, and 30 °C. Dashed black lines represent the 2.5 and 97.5 quantiles.

Figure A6

Estimated posterior distributions of Λ_G(T), the average duration of gonotrophic cycle at 25 and 30 °C. Dashed black lines represent the 2.5 and 97.5 quantiles. Solid red lines represent the average value for subtropical Ae. albopictus.

Figure A7

Estimated posterior distributions of Λ_NG(T), the number of gonotrophic cycles completed on average by a female mosquito at 25 and 30 °C. Dashed black lines represent the 2.5 and 97.5 quantiles. Solid red lines represent the average value for subtropical Ae. albopictus.

Figure A8

Estimated posterior distributions of Λ_NE(T), the number of eggs laid on average by a female mosquito at 25 and 30 °C for each gonotrophic cycle. Dashed black lines represent the 2.5 and 97.5 quantiles. Solid red lines represent the average value for subtropical Ae. albopictus.

Figure A9

Distributions of quantities of interest for simulated (1000 simulations) life history of 1000 initial eggs at 25 °C. (a) Number of hatched eggs; (b) time for egg development; (c) number of emerging adults; (d) time of development from the egg stage; (e) adult longevity; (f) total number of eggs laid by all females. Dashed red lines represent the 2.5 and 97.5 quantiles, solid red lines represent the average value.

Figure A10

Distributions of quantities of interest for simulated (1000 simulations) life history of 1000 initial eggs at 30 °C. (a) Number of hatched eggs; (b) time for egg development; (c) number of emerging adults; (d) time of development from the egg stage; (e) adult longevity; (f) total number of eggs laid by all females. Dashed red lines represent the 2.5 and 97.5 quantiles, solid red lines represent the average value.

Figure 1

Comparison between temperate Ae. albopictus (black) and subtropical Ae. albopictus (orange) results for each tested temperature (10, 15, 25, and 20 °C). (a): Fraction of hatched eggs; (b): fraction of L1 larvae that successfully reached the adult stage; (c): length of time between immersion of eggs in water and hatching response; (d): duration of development from L1 to adult. Points: average values. Vertical lines: 95% Confidence Intervals (average ±1.96∙SE).

Figure 2

Survival rate of Ae. albopictus females adjusted to the Weibull’s model at temperatures of 15, 25, and 30 °C.