Archive for the ‘climatic change’ Category

Impact of the rosette weevil on yellow starthistle

March 13, 2017 Leave a comment

Yellow starthistle (Centaurea solstitialis L.) (YST) is an invasive weed native to the Mediterranean region with a geographical centre of diversity in Turkey. It is widely established in Chile, Australia, and western North America. It arrived in California as a contaminant in alfalfa seed in 1859 and, by 2002, had infested more than 7.7 million hectares in the U.S.A. Biological control of YST using capitula feeding weevils, picture wing flies and a foliar rust pathogen has been ongoing in the western U.S.A. for more than three decades with limited success. Modelling and field research suggest natural enemies that kill whole plants and/or reduce seed production of survivors are good candidates for successful biological control. A candidate species with some of these attributes is the rosette weevil Ceratapion basicorne (Illiger). In the present study, a model of the rosette weevil is added to an extant system model of YST and its capitula feeding natural enemies and, in a GIS context, is used to assess YST control in the Palearctic region and the weevil’s potential impact on YST in western U.S.A. The results obtained suggest densities of mature YST plants in western U.S.A. would be reduced by 70–80% in many areas.

Gutierrez A.P., Ponti L., Cristofaro M., Smith L., Pitcairn M.J., 2016. Assessing the biological control of yellow starthistle (Centaurea solstitialis L.): prospective analysis of the impact of the rosette weevil (Ceratapion basicorne (Illiger)). Agricultural and Forest Entomology,

The rosette weevil Ceratapion basicorne.

Can climate change influence olive pests and diseases?

September 26, 2009 Leave a comment

Climate change will make the Mediterranean Basin vulnerable to desertification, and this will affect many species such as olive in largely unknown ways. Olive is the base of a tri-trophic food web that includes pest, disease and their natural enemy species, each of which will be affected differently by climate change. The effects of extant weather and climate change scenarios on the tri-trophic interactions can be examined using biologically-rich physiologically-based demographic models developed from field and laboratory data. Studies from Sardinia, Italy and California show how the same model can be applied to these areas, and by inference, to other areas of the Mediterranean basin and elsewhere globally. Specifically, the model enables the examination of climate change on the range of olive and olive fly. The effect of climate change on natural enemies are illustrated using the olive scale/parasitoid interactions. The same system can also be used to examine the distribution and abundance of diseases. No model is complete, and required improvements can serve as a basis for interdisciplinary regional IPM research.

Gutierrez A.P., Ponti, L., 2009. Can climate change have an influence on the occurrence and management of olive pests and diseases? 4th European Meeting of the IOBC/WPRS Working Group “Integrated Protection of Olive Crops”, Córdoba, Spain, 1-4 June 2009. (Keynote address)

Mediterranean-wide analysis of the olive-olive fly system

August 6, 2009 Leave a comment

The Mediterranean Basin is expected to be particularly vulnerable to climate change including pronounced climate warming and desertification. Olive (Olea europaea) is of eco-social importance in the Mediterranean where it was domesticated, and it is also considered a sensitive climate indicator. This crop and its major pest, the olive fly Bactrocera oleae are a suitable model system to study Mediterranean climate. A weather-driven physiologically-based demographic model (PBDM) of olive and olive fly ( is being used to analyze this plant-pest system in the Mediterranean region based on ERA-40 weather data ( downscaled via the regional climate model RegCM3 coupled to the MIT ocean model. PBDM predictions are mapped with the open source GIS GRASS (

Ponti L., Gutierrez A.P., Ruti P.M., 2009. The olive–Bactrocera oleae system in the Mediterranean Basin: a physiologically based analysis driven by the ERA-40 climate data. 5th Study days “Models for Plant Protection”, Piacenza, Italy, 27-29 May 2009.