First report of the influence of temperature on the bionomics and population dynamics of Aedes koreicus, a new invasive alien species in Europe

Abstract

Background: Aedes koreicus was detected in northern Italy for the first time in 2011, and it is now well established in several areas as a new invasive mosquito species. Data regarding the influence of temperature on mosquito survival and development are not available yet for this species. Methods: We experimentally investigated the influence of different constant rearing temperatures (between 4 and 33 °C) on the survival rates and developmental times of different life stages of Ae. koreicus under laboratory conditions. The resulting data were subsequently used to inform a mathematical model reproducing the Ae. koreicus life-cycle calibrated to counts of adult females captured in the field in the autonomous province of Trento (northern Italy) between 2016 and 2018. Results: We found that temperatures above 28 °C are not optimal for the survival of pupae and adults, whereas temperate conditions of 23-28 °C seem to be very favorable, explaining the recent success of Ae. koreicus at establishing into new specific areas. Our results indicate that Ae. koreicus is less adapted to local climatic conditions compared to Ae. albopictus, another invasive species which has been invading the area for the last three decades. Warmer seasons, which are more likely to occur in the future because of climate change, might extend the breeding time and therefore increase the abundance of Ae. koreicus in the study region. Conclusions: Our findings provide, to our knowledge, the first evidence on how temperature influences the bionomics and dynamics of Ae. koreicus and highlight the need for further studies on the phenology of this species in temperate areas of Europe.

Dynamics and Distribution of the Invasive Mosquito Aedes koreicus in a Temperate European City

“…koreicus adult females collected in each sampling site. We then calibrated a previously published mathematical model, defined as a "population model" [21], to the weekly number of trapped mosquitoes averaged over the 10 collection sites. The model provides a daily estimate of Ae.…”

“…koreicus dynamics for each population stage (eggs, larvae, pupae and adults) explicitly considering temperature, as it drives most of the developmental and survival rates. More specifically, such rates are estimated through temperature-dependent functions calibrated on the experiments presented in the same study, allowing also for some uncertainty [21]. The population model has two free parameters: the daily capture rate of adult mosquitoes α and a density-dependent scaling factor K driving the carrying capacity for the larval stages.…”

“…Similarly to other mosquito species, in laboratory conditions, temperature was found to have a strong influence on the biology of Ae. koreicus, affecting, for instance, the developmental time and survival of immature stages and adult longevity [21]. In particular, temperatures ranging between 23 and 28 • C are favorable for this species' development [21], explaining its recent success at establishing itself in new temperate European areas.…”

“…koreicus within a temperate European city by providing new data on the species abundance in space and time in Pécs, Hungary. For this purpose, we applied a previously published mathematical model [21], which is explicitly driven by temperature, to replicate the observed mosquito dynamics and provide an estimate of Ae. koreicus density over the whole city.…”

“…koreicus density over the whole city. This kind of model has been widely used to investigate mosquito dynamics, also within an epidemiological framework [22][23][24][25], and is usually temperature-dependent as this abiotic factor plays a key role at shaping mosquito survival and development [21,[26][27][28].…”