Tolerance thresholds for Aedes albopictus and Aedes caspius in Italian urban areas.

With nuisance mosquito species, the goal of integrated pest management is to keep mosquito density below a tolerance level that is often set by economic, ecological, and political factors. This study compares actual human annoyance, as measured by a phone survey, with several measures of mosquito abundance, in order to determine a threshold that is both relevant and practical. The efficiency of CO2-baited traps, container index (CI), and oviposition traps for monitoring Aedes albopictus, and CO2-baited traps for monitoring Aedes caspius, was evaluated. CO2-baited traps were confirmed to be of low efficiency in Ae. albopictus collection, while correlation matrices showed a good relationship between CI and the number of eggs collected (R = 0.91), and between number of eggs and phone-survey nuisance level estimates (R = 0.88). Correlation between CI and phone-survey nuisance levels was slightly lower (R = 0.78). We found a close relationship between the nuisance level declared by residents and mosquito captures obtained with CO2-baited traps (Ae. caspius) and ovitraps (Ae. albopictus). An equation is presented to estimate annoyance according to dwelling characteristics and to the presence of children in the family.

Meteorological and oceanographic conditions in the northern Adriatic Sea during the period June 1999-July 2002: influence on the mucilage phenomenon.

Mucilage events (formation of very large organic aggregates and gelatinous surface layers) have been documented several times during the past two centuries in the northern Adriatic Sea (NA), while their frequency has significantly increased since 1988. In this work, meteorological and oceanographic conditions in the NA during the period June 1999-July 2002 are described and their relation to the outbreak and fate of the mucilage phenomenon was investigated. Salinity and temperature data were collected during approximately monthly cruises along three transects in the NA. Relevant meteorological situations (air temperature, rainfall, wind) were selected from large-scale ECMWF analyses and from the Local Analysis and Prediction System (LAPS; Emilia Romagna Meteorological Service), while sea conditions (waves) were analysed by means of the Wave Adriatic Model (WAM). Data for air temperature, rainfall, and wind from several meteorological stations in the region were used. Average seasonal cycles of sea temperature and salinity simulated with statistical models, based on historical data collected in the NA since 1972, were used to determine thermal and haline anomalies. The monthly anomaly variability of maximum and minimum air temperatures, rainfall amount and number of rainy days did not appear to be relevant for the mucilage phenomenon outbreak. In contrast, both vertical and horizontal thermohaline gradients in the region were more developed during late spring and summer of 2000 and particularly of 2002, when the mucilage events were of greatest extent in space and time, compared to 2001 (short-lived event) and 1999 (no event). These more pronounced gradients were due to a combination of several unusual conditions: sharp heating of the sea surface in May-June, domination of eastwards transport of freshened waters formed in the Po Delta area, and intrusion of very high salinity intermediate waters originating in the eastern Mediterranean. Moreover, in winter of both 2000 and 2002 very dense and cold water formed and remained in the bottom layer until spring, contributing to increase the stratification degree of the water column. The duration of the mucilage events and their spatial distribution in the region depend strongly on meteorological changes. Recurrent anticyclonic conditions, characterized by low wind and calm sea, favour extended events in time (up 2 months in 2002). In contrast, highly perturbed weather, particularly due to strong "bora" wind, can be determined in sharp decay of the event (e.g. in July 2000).