Use of BG-sentinel traps for the monitoring of Culicidae in the city of Bologna

The Culicidae family comprises mosquitoes which are involved in the transmission of pathogenic agents among the most dangerous for humans. In particular the sanitary importance of the tiger mosquito is essentially related to its role of potential vector for numerous exotic human pathologies (Dengue, yellow fever) as well as some pathologies characteristic of the Mediterranean basin (West Nile and Dirofiliaria). Because of this we have been charged by the Municipality of Bologna, with a specific convention, to monitor and verify the disinfestation activities as part of a campaign against the tiger mosquito. Quality controls on disinfestations and marking of gutters in public areas as well as inspection of schools premises have been performed. Furthermore, following the 2007 epidemic outbreak of Chikungunya (217 confirmed cases; the first autochthonous CHIKV outbreak in Europe) and the more recent epidemic West Nile Disease in Emilia Romagna, a surveillance plan has been set up which involves the capture of adult insects by BG-SENTINEL traps. These traps have been chosen for this survey because of their innovative insects attraction system, consisting of chemical substances which resemble the human bodies ones. These traps, used for the first time in the area of the City of Bologna, have proven to capture very efficiently different mosquitoes in the territory among which the tiger mosquito, usually difficult to capture with the other traditional systems. Currently 8 monitoring stations are active, evenly distributed in the city of Bologna, but others will be placed in the future. Due to the fragility of the used materials and the need of electric power for the functioning, fenced green areas around communal libraries, schools and retirement houses have been favored to host the monitoring stations. The preliminary results show some differences among the traps, which are due to the micro-environmental characteristics of the chosen sites. In particular: total number of captured mosquitoes; variety of captured species; relationship among the different species. All the traps have captured mainly Aedes albopictus and Culex pipiens, with significant differences between traps, but the captures of other species were poorly represented (Culex hortensis, Culiseta longiareolata, Ochlerotatus caspius and Anopheles maculipennis). The traps that have captured a significant percentage of one or both of the examined species allow to observe their different seasonal patterns.