May climate change allow the spread of the Asian tiger mosquito, vector of viruses, in central Europe?

Aedes albopictus, also known as the Asian tiger mosquito, is a native species of tropical and subtropical areas of Southeast Asia, recently spread also to Europe. Ae. albopictus represents a serious threat for human health because it is an important vector of many viruses. The geographical distribution of the mosquito’s populations is limited by cold climate. However, according to projections, due to the climate change the species could spread in many regions where it is now not established. The key factor that allowed Ae. albopictus to colonize new territories in higher latitudes may be the production of cold-tolerant diapausing eggs. The aim of this study is to determine the parameters for the production of diapausing eggs by Ae. albopictus and for the eggs hatching. According to our data, the diapausing eggs are induced by a 11 hours of light and 13 of dark photoperiod that, in central Italy, is reached during the middle of October. Thank to this mechanism, the mosquito can avoid the exposition to low temperature of the most susceptible stage of development, the first instar larva, that cannot survive under 10°C. The results are discussed in relation to the scenario of the global warming.