- 30
- Ott
- 2026
Larvicidal efficacy and lasting activity of a silicon based granular formulation on Aedes albopictus and Culex pipiens in urban setting
Ottobre 30, 2026Fiorente F, M Pusinanti, F Nicassio, R Veronesi, M Carrieri, L Donati, R Bellini
XXIV ESOVE Congress, 27-30 Ottobre 2026, Valencia, Spagna
Culex pipiens and Aedes albopictus, species of significant public health interest. Local administrations require larvicidal solutions that guarantee good persistence to rationalize resources while reducing intervention cycles, particularly under intense, sudden rainfall conditions. This study evaluates the efficacy of a new slow-release granular silicone formulation (AQUATAIN GR) compared to a widely used liquid polydimethylsiloxane product (AQUATAIN AMF).
Two consecutive field tests were conducted in summer 2025 on 50 road drains in Modena, Italy. Drains were randomly divided into three groups: 20 treated with AQUATAIN GR (24 g/drain), 20 with AQUATAIN AMF (5 ml/ drain), and 10 untreated controls. Sampling of mature larvae (L3–L4) and pupae was carried out weekly up to 34–44 days post-treatment. Efficacy was evaluated via percent larval-pupal reduction compared to the control, corrected using Abbott’s formula.
Both formulations demonstrated appreciable larvicidal persistence up to the fourth week post-treatment, despite adverse weather events. At week four, AQUATAIN GR recorded larval density reductions of 83.93%
(1st test) and 83.71% (2nd test), showing possible better lasting activity, although not statistically significant, compared to AQUATAIN AMF (50.31% and 79.84%). A temporary drop in AQUATAIN GR efficacy observed in the second week, attributable to the wash-off effect of intense rain events recorded in the days preceding the sampling, was followed by a rapid recovery of efficacy, suggesting a gradual release dynamic of the granular formulation.
The tested granular formulation may represent an innovative and practical solution for the optimization of urban vector control, showing significant resilience to weather events: although subject to a temporary drop in efficacy immediately after intense rainfall, its gradual release dynamic allows for a rapid recovery of the larvicidal activity, ensuring an overall residual protection for up to four weeks.
Two consecutive field tests were conducted in summer 2025 on 50 road drains in Modena, Italy. Drains were randomly divided into three groups: 20 treated with AQUATAIN GR (24 g/drain), 20 with AQUATAIN AMF (5 ml/ drain), and 10 untreated controls. Sampling of mature larvae (L3–L4) and pupae was carried out weekly up to 34–44 days post-treatment. Efficacy was evaluated via percent larval-pupal reduction compared to the control, corrected using Abbott’s formula.
Both formulations demonstrated appreciable larvicidal persistence up to the fourth week post-treatment, despite adverse weather events. At week four, AQUATAIN GR recorded larval density reductions of 83.93%
(1st test) and 83.71% (2nd test), showing possible better lasting activity, although not statistically significant, compared to AQUATAIN AMF (50.31% and 79.84%). A temporary drop in AQUATAIN GR efficacy observed in the second week, attributable to the wash-off effect of intense rain events recorded in the days preceding the sampling, was followed by a rapid recovery of efficacy, suggesting a gradual release dynamic of the granular formulation.
The tested granular formulation may represent an innovative and practical solution for the optimization of urban vector control, showing significant resilience to weather events: although subject to a temporary drop in efficacy immediately after intense rainfall, its gradual release dynamic allows for a rapid recovery of the larvicidal activity, ensuring an overall residual protection for up to four weeks.