Studying mosquito vector bionomics and behaviour to boost pyrethroid-free invasive mosquito control in urban areas

STUDYING MOSQUITO VECTOR BIONOMICS AND BEHAVIOUR TO BOOST PYRETHROID-FREE INVASIVE MOSQUITO CONTROL IN URBAN AREAS Martina Micocci (a), Nigel Beebe (b), Beniamino Caputo (a), Alessandra della Torre (a) (a) Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy (b) School of Biological Sciences, University of Queensland, Brisbane, Australia Background: Aedes invasive mosquitoes are responsible for the global transmission of tropical arboviruses, such as Dengue and Chikungunya - a major public health problem of increasing importance also in temperate regions due to the establishment and spread of Aedes albopictus. The control of Aedes densities, nuisance and arbovirus transmission is still largely dependent from pyrethroid insecticides, but their environmental impact and the spreading of resistance urge for the need to develop innovative pyrethroid-free control approaches, such as Sterile-Insect Technique (SIT, based on release of irradiated males), Incompatible Insect Technique (IIT, based on the release of males with a different endosymbionts Wolbachia strains from those present in wild females capable of inducing cytoplasmic incompatibility) or “auto-dissemination” of Pyriproxyfen (PPF, an Insect Growth Regulator interfering with adult emergence to be exploited to overcome the difficulty in targeting the multiplicity of larval sources). My PhD thesis is focused on studies devoted to better characterize aspects of mosquito bionomics and behaviour (e.g., dispersal, survival, resistance to insecticides) relevant for the design and implementation of integrated management strategies against Ae. albopictus in urban areas of temperate regions. Here, I describe the experiments and preliminary results achieved during the 5 month-visit at University of Queensland. Methods: First, a Mark-Release-Recapture (MRR) was carried out: >12,000 Aedes aegypti males were reared, marked with 6 fluorescent dusts by a novel marking technique using polystyrene beans, released at daytime and night-time per 3 replicates in about 100-sqm area in Goomeri (QLD), and recaptured daily for 7 days by 40 BG-Sentinel traps. Second, a preliminary experiment was carried out under laboratory conditions to test the hypothesis that feeding males with PPF could bring an increase in population suppression through contamination of females by mating. Results: Preliminary results of the MRR show significant higher longevity and dispersal than previously assumed, as well as disproved previous indications suggesting that releases during night hours could be more effective than daily ones. Results of PPF test are under analysis. Discussion: The acquired skills and the expertise developed during the first half of my PhD studies in the group of medical entomology in DSPMI, at Entostudio and at University of Queensland are at the basis of the development of the research activities to be carried out on Aedes albopictus in Rome during the second part of the PhD.