Posts

Showing posts with the label population ecology

Establishment and impact of tiger mosquito in Europe

Image
The Asian tiger mosquito ( Aedes albopictus ) is one of the most invasive disease vectors worldwide. The species is a competent vector of dengue, chikungunya, Zika viruses and other severe parasites and pathogens threatening human health. The capacity of this mosquito to colonize and establish in new areas (including temperate regions) is enhanced by its ability of producing diapausing eggs that survive relatively cold winters. The main drivers of population dynamics for this mosquito are water and air temperature and photoperiod. In this paper, we present a mechanistic model that predicts the potential distribution, abundance and activity of Asian tiger mosquito in Europe. The model includes a comprehensive description of: i) the individual life-history strategies, including diapause, ii) the influence of weather-driven individual physiological responses on population dynamics and iii) the density-dependent regulation of larval mortality rate. The model is calibrated using field data ...

Risk assessment for tiger mosquito in Europe

Image
The Asian tiger mosquito ( Ae. albopictus ) is indigenous to the oriental region, but is now widespread throughout the world. It is an aggressive mosquito, which causes nuisance and is well known vector of important human disease. It is one of the world’s most invasive species and is now invading Europe by both natural means and human assisted dispersal. Currently, there is no consensus on the limits of its potential geographic distribution in Europe. For this reason, studying the role that environmental driving variables, mainly temperature, play in determining the spatial variation of the potential population abundance of the mosquito should be considered a high priority. To assess the risk posed by Ae. albopictus to Europe, a lattice model based on the temperature-dependent physiologically based demographic modelling approach has been developed and is being tested against field observations. The area of potential distribution of this insect is simulated as driven by current climate...

Invasive potential of medfly in California and Italy

Image
Since being detected in California in 1975, the polyphagous tropical Mediterranean fruit fly ( Ceratitis capitata Weid. (medfly)) has been the subject of a large-scale eradication campaign in the absence of sound knowledge of its invasive potential. We use a weather-driven physiologically-based demographic system model ( CASAS ) embedded in a GIS based on GRASS to examine medfly's potential distribution across Arizona-California (AZ-CA), and Italy where its establishment is documented. AZ is unfavorable for medfly because of high summer temperatures, while much of CA, including many frost-free areas, is too cold during winter. Only the south near coastal region of CA is predicted to be potentially favorable for medfly, but in the absence of consistent measurable populations, we cannot say if medfly is established there. Medfly has been established in Italy for decades, and our model predicts a wide distribution in the southern and western regions of the country. Gutierrez A.P.,...

Sardinia olive systems in a warmer climate

Image
In the Mediterranean Basin, major islands including Sardinia are considered particularly vulnerable to global warming and desertification. We used a physiologically based demographic model (PBDM) of olive and olive fly to analyze in detail this plant-pest system in Sardinia under observed weather (ten years of daily data from 48 locations), three climate warming scenarios (increases of 1, 2 and 3 °C in average daily temperature), and a 105-year climate model scenario for the Alghero (e.g. 1951-2055). GRASS GIS was used to map model predictions, and model calibration with field bloom date data was performed to increase simulation accuracy of olive flowering predictions under climate change. As climate warms, the range of olive is predicted to expand to higher altitudes and consolidate elsewhere, especially in coastal areas. The range of olive fly will extend into previously unfavorable cold areas, but will contract in warm inland lowlands where temperatures approach its upper thermal li...