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Archive for the ‘Tuta absoluta’ Category

PBDMs for evidence-based pest risk assessment

November 26, 2015 Leave a comment

The distribution and abundance of species that cause economic loss (i.e., pests) in crops, forests or livestock depends on many biotic and abiotic factors that are thought difficult to separate and quantify on geographical and temporal scales. However, the weather-driven biology and dynamics of such species and of relevant interacting species in their food chain or web can be captured via mechanistic physiologically based demographic models (PBDMs) that can be implemented in the context of a geographic information system (GIS) to project their potential geographic distribution and relative abundance given observed or climate change scenarios of weather. PBDMs may include bottom-up effects of the host on pest dynamics and, if appropriate, the top-down action of natural enemies. When driven by weather, PBDMs predict the phenology, age structure and abundance dynamics at one or many locations enabling projecting the distribution of the interacting species across wide geographic areas. PBDMs are able to capture relevant ecosystem complexity within a modest number of measurable parameters because they use the same ecological models of analogous resource acquisition and allocation processes across all trophic levels. The use of these analogies makes parameter estimation easier as the underlying functions are known. This is a significant advantage in cases where the available biological data is sparse.

Ponti L., Gilioli G., Biondi A., Desneux N., Gutierrez A.P., 2015. Physiologically based demographic models streamline identification and collection of data in evidence-based pest risk assessment. EPPO Bulletin, 45: 317-322. http://dx.doi.org/10.1111/epp.12224

PBDM sub-models used for all species.

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Holistic approach in invasive species research

December 15, 2014 Leave a comment

The Mediterranean Basin is a climate change and biological invasion hotspot where recent warming is facilitating the establishment and spread of invasive species, one of which is the highly destructive South American tomato leafminer (Tuta absoluta). This pest recently invaded the Mediterranean Basin where it threatens solanaceous crops. Holistic approaches are required to project the potential geographic distribution and relative abundance of invasive species and hence are pivotal to developing sound policy for their management. This need is increasing dramatically in the face of a surge in biological invasions and climate change. However, while holistic analyses of invasive species are often advocated, they are rarely implemented. We propose that physiologically-based demographic models (PBDMs) in the context of a geographic information system (GIS) can provide the appropriate level of synthesis required to capture the complex interactions basic to manage invasive species such as T. absoluta. We review the PBDMs for two invasive flies, and use them as a basis for assessing the biological data available for the development of a PBDM for T. absoluta, and in the process identify large data gaps that using the PBDM as a guide can be easily filled. Other components for an ecologically-based management program for this pest (habitat modification, natural and classical biocontrol, pheromones, and others) are also reviewed. The development of a PBDM for T. absoluta would provide the basis for an interdisciplinary agroecological synthesis of the problem and the role different control tactics would play in region-specific control of the pest.

Ponti L., Gutierrez A.P., Altieri M.A., 2015. Holistic approach in invasive species research: the case of the tomato leaf miner in the Mediterranean Basin. Agroecology and Sustainable Food Systems, http://dx.doi.org/10.1080/21683565.2014.990074 | Get a free reprint

PBDM sub-models used for all species in all trophic levels.

Agroeocological management of invasive species

May 4, 2012 Leave a comment

During a meeting of the Italian National Academy of Entomology held in Florence on 18 February 2012, Luigi Ponti delivered a public lecture titled “Management of invasive species in the frame of an agro-ecological vision: the case study of Tuta absoluta (Meyrick)”. The talk was part of a workshop on T. absoluta where Italian research stakeholders reported on this major invasive pest problem for the Mediterranean Basin. Dr. Ponti’s talk focused on how physiologically-based weather-driven demographic models (CASAS models) integrated into a GIS may aid ecologically-based management of invasive species such as T. absoluta by sorting out the complexity of the global change biology involved. Examples of how invasive species can be assessed in the frame of an agro-ecological vision were provided and prospective applications to T. absoluta outlined along with common misunderstanding about invasive species that may be clarified using the modeling approach of the GlobalChangeBiology project.

Indice di rischio invasioni biologiche (da http:/dx.doi.org/10.1511/2009.78.203)