The diversity of mosquito interactions under climate change conditions

The spread of mosquito-borne diseases is restricted by the occurrence of competent vectors. In addition to the native Culex pipiens, a vector for West Nile and Usutu virus, invasive species such as Aedes albopictus and Ae. japonicus are flourishing in Europe. Their spread towards more temperate regions poses an increasing threat because of their high vector competences for different viruses such as chikungunya, dengue and Japanese Encephalitis. The establishment of invasive mosquitoes is influenced by several factors, such as climate conditions and interspecific interactions. Shifts in the distribution and abundance of native and invasive mosquitoes suggest occurrence of competitive displacement in shared larval habitats of these container breeding species.

Several populations of Cx. pipiens, Ae. albopictus and Ae. japonicus were collected from breeding sites in Belgium, Germany and Italy and both Cx. pipiens and Ae. albopictus have been reared at ITM’s Insectary. Additional test on the swarming ecology of Ae. japonicus will be done in collaboration with Polo GGB to provide a first European lab colony. For each species, life history and metabolic responses will be tested in function of larval food qualities like algae and detritus given in low and high quantity by means of dose-response experiments.

The context-dependency of interspecific larval interactions will be examined in different populations. Artificial breeding sites will be created to test interspecific larval interaction under different food and temperature conditions. These two explanatory variables can be compared with several response variables (survival, development time and metabolism) via the response-surface design. Each surface block will be repeated for each country under different food and temperature conditions to explore the relationship between these variables.

Based on these results, treatments will be selected to test their vector competence in collaboration with the Bernhard Nocht Institute. Both entomological and virological datasets will be cross-cut in order to change species and community specific ecological results on context dependent vector diversity and abundances. This will result in a more conceptual estimation of how microhabitat diversity is shaping the relative risk of mosquito-borne diseases in Europe.