Pilot study to evaluate alternative and eco-friendly methods for mosquito control in an urban area (Italy)

Pilot study to evaluate alternative and eco-friendly methods for mosquito control in an urban area (Italy) A. Michelutti1, S. Vettore2, F. Gradoni1, S. Carlin1, M. Micocci3, D. Bonetto2, A. Drago2, S. Martini2 and F. Montarsi1 1IZSVe, Viale dell’Università 10, 35020 Legnaro, Italy, 2Entostudio s.r.l., Viale del Lavoro 66, Ponte San Nicolò, 35020 Legnaro, Italy, 3Sapienza Università di Roma, Piazzale Aldo Moro 5, 00185 Rome, Italy; amichelutti@izsvenezie.it Mosquito control is one of the main preventive measures of mosquito-borne diseases transmission. In this study, we present the results of a pilot study where the use of a biodegradable larvicide, communication campaigns and citizen involvement have been implemented. The study was carried out in the summers of 2021 and 2022 in a village of Northeast Italy (Ponte di Piave, Veneto Region). In this site, a selected area (treated area) was applied a vegetal oil with physicalmechanical action in all catch basins located in public areas while in another area (control area) catch basins were treated with Diflubenzuron and VectoMax® FG. In the treated area, door-to-door visits were conducted to inform population and provide information material and larvicide for free. Meetings were held with the population to inform them of the aims of the project. To monitor the efficacy of the two control methods, 47 out 350 catch basins were inspected 10–14 days after larvicide application to assess larvae presence; in addition, eight ovitraps were placed both in the treated and in the control area. In 2021, the average of positive catch basins in treated area increased of 39.3% while decreased of 63.7% in control area. The average number of eggs per collection was higher in treated area (257.3 eggs/ovitrap) compared to control area (212.5 eggs/ovitrap). Due to these results, in 2022, the vegetal oil has been applied more frequently and at twice dosage than that recommended by the company. In 2022, the average of positive catch basins decreased after treatments in both the treated and control area of 51.5% and 87.3%, respectively. In 2022, the average number of eggs per collection was lower in the treated area than in the control area (139.1 eggs/ovitrap vs 172.2 eggs/ovitrap). In conclusion, the vegetable oil-based larvicide was not effective in public area applications due to the low persistence in catch basins. For the public administration, its cost for application is higher than the traditional larvicide use. In private areas, its use is recommended, since it is safe for citizens, who can frequently apply it (weekly) in non-removable larval breeding sites. However, in 2022, the implementation of communication campaigns resulted in fewer mosquito numbers (meaning as eggs/ovitrap) in the treated area than in the control. This work was carried out in the frame of the CCM Project ‘Preventing vector-borne diseases through the development and pilot implementation of new operational supporting tools’.