Fig 1.
Map of study sites in Rome (Italy).
(A) Sapienza University hospital “Policlinico Umberto I” = insecticide treated site (right panel); dark grey = buildings; light grey = open areas; blue line = itinerary of the insecticide cannon sprayer; lines of black stars = exposed mosquito cages at 10, 30, 50 and 70 m from insecticide spraying; VC-1 and VC-2 = validation mosquito cages. (B) Department of Philosophy, Sapienza University = untreated site (same scale as A). Yellow dots = sticky traps. Background: OpenStreetMap data rendered with Landscape style, by opencyclemap.org, Map data OpenStreetMap contributors, CC BY-SA 2.0.
Table 1.
Binomial Generalized Linear Mixed Model of Aedes albopictus mortality in cages exposed and non-exposed to insecticide spraying.
Fig 2.
Expected effectiveness of insecticide sprayings in study area based on mortality observed in caged mosquitoes.
(A) Expected Aedes albopictus adult mortality modelled as a function of the distance between the cages and the insecticide treatments (T2-T8), as predicted by GLMM-2. Central solid line = fitted values determined by the intercept and distance effect (fixed part); dashed lines = 95% confidence interval; grey area = uncertainty in predicted values due to variations in random terms (date and cage locations); circles = observed mortality values in validation cages (VC-1 and VC-2, 13m and 41m distant from spraying, respectively), either statistically different (empty circles) or non-statistically different (filled circles) from values simulated by GLMM-2. (B) Spatialized expected mosquito mortality modelled as a function of distance taken from binomial GLMM-2 result (fixed part) (central solid line in panel A). Lines of black stars = mosquito cages at 10, 30, 50 and 70 m from insecticide spraying. VC-1 and VC-2 = cages inside treated area used for GLMM-2 validation. Background: OpenStreetMap data rendered with Landscape style, by opencyclemap.org, Map data OpenStreetMap contributors, CC BY-SA 2.0.
Fig 3.
Plots of predicted mean Aedes albopictus abundance as a function of water leftover in sticky traps.
Predictions in untreated and treated sites based on GLMM-3. X-axis = water leftover after 72 hours (5 dl initial water level; values>5 dl due to rainfall and/or artificial watering); Y-axis = predicted mean abundance in sticky traps; solid lines = predicted mean value; dashed lines = 95% confidence intervals.
Table 2.
Poisson Generalized Linear Mixed Model of Aedes albopictus counts in sticky traps in insecticide treated and untreated sites.
Fig 4.
Change point analysis of Aedes albopictus abundance and of water leftover in study sites.
(A) Seasonal pattern of mosquito abundance in insecticide-treated (green line, N = 24) and untreated (black line, N = 19) sites. (B) Correlation of residual of mosquito time series between treated and untreated sites. (C) Seasonal pattern of water leftover in sticky traps in insecticide-treated (green line, N = 24) and untreated (black line, N = 19) sites. (D) Correlation of residual of water leftover time series between treated and untreated sites. Solid circles = significant correlation estimates (p-value < 0.05). Empty circles = non-significant correlation estimates (p-value > 0.05). Blue horizontal line in B and D panels = fitted mean in each sequence; each break identifies a statistically significant change in mean. Vertical bars in A and C panels = 95% confidence intervals. X-axis = 2013 collection dates. Vertical dotted lines = dates of insecticide sprayings.