Investigation on key aspects of mating biology in the mosquito Aedes koreicus

Aedes koreicus Edwards, 1917 (Hulecoetomyia koreica) is a mosquito (Diptera: Culicidae) from Northeast Asia with a rapidly expanding presence outside its original native range. Over the years, the species has been discovered in several new countries, either spreading after first introduction or remaining localised to limited areas. Notably, recent studies have demonstrated the ability of the species to transmit zoonotic parasites and viruses both in the field and in laboratory settings. Combined with its invasive potential, the possible role of Ae. koreicus in pathogen transmission highlights the public health risks resulting from its invasion. In this study, we used a recently established population from Italy to investigate aspects of biology that influence reproductive success in Ae. koreicus: autogeny, mating behaviour, mating disruption by the sympatric invasive species Aedes albopictus Skuse, 1894, and the presence of the endosymbiont Wolbachia pipientis Hertig, 1936. Our laboratory population did not exhibit autogenic behaviour and required a bloodmeal to complete its ovarian cycle. When we exposed Ae. koreicus females to males of Ae. albopictus, we observed repeated attempts at insemination and an aggressive, disruptive mating behaviour initiated by male Ae. albopictus. Despite this, no sperm was identified in Ae. koreicus spermathecae. Wolbachia, an endosymbiotic bacterium capable of influencing mosquito reproductive behaviour, was not detected in this Ae. koreicus population and, therefore, had no effect on Ae. koreicus reproduction.