Archive for the ‘Invasive species’ Category

Crop-pest dynamics in the Mediterranean Basin

September 30, 2016 Leave a comment

Climate change will make assessing and managing crop-pest systems in the Mediterranean Basin more difficult than elsewhere on the globe. The Basin is in many ways a hot spot of global change, as higher than average projected climate change threatens an extremely rich and intertwined biological and cultural diversity, and increases its vulnerability to biological invasions. As a consequence, pest problems in this hot spot will require a holistic approach to deconstruct the elusive complex interactions that are the underpinning basis for sound decision making at the field level. Building on 30+ years of multidisciplinary progress inspired by pioneering work at University of California, the ENEA GlobalChangeBiology project in collaboration with CASAS Global is developing an interdisciplinary tool to mechanistically describe (i.e., model), analyze and manage agro-ecological problems based on the unifying paradigm that all organisms including humans acquire and allocate resources by analogous processes – the paradigm of ecological analogies that is holistic by design. Recent analyses using this approach show how the tool provided and will continue to provide governmental agencies with the scientific basis for building eco-social resilience to climate warming into agricultural systems across the Mediterranean Basin and elsewhere.

Ponti L., Gutierrez A.P., Iannetta M., 2016. Climate change and crop-pest dynamics in the Mediterranean Basin. ENEA Technical Report, 27: 18 pp., | Open access

Growth rates of a crop, pest and natural enemy plotted on temperature to intuitively illustrate how an increase in average temperature from T0 to T+2°C may affect the physiological basis of trophic interactions. With temperature warming, biological control of the pest may decrease due to the narrower temperature tolerance of the natural enemy compared to the pest.

Invasiveness of spotted wing Drosophila

September 10, 2016 Leave a comment

The polyphagous Asian vinegar fly Drosophila suzukii (spotted wing Drosophila) is a native of Eastern and Southeastern Asia. It emerged as an important invasive insect pest of berries and stone fruits in the Americas and Europe beginning in 2008. Species distribution models are commonly used for analyzing the extant and potential range expansion of invasive species. Previous modeling efforts for D. suzukii include a degree-day model, a MaxEnt ecological niche model, a demographic model incorporating the effects of temperature, and a preliminary mechanistic physiologically-based demographic model (PBDM). In the present analysis, we refine the PBDM for D. suzukii based on biological data reported in the literature. The PBDM is used to assess the effects of temperature and relative humidity from a recently published global climate dataset (AgMERRA) on the prospective geographic distribution and relative abundance of the pest in the USA and Mexico, and in Europe and the Mediterranean Basin. Our focus is on areas of recent invasion and of predicted higher invasiveness in these areas. Although the species is native to Asia and is of putative temperate origins, it has established in subtropical to north temperate zones worldwide where it infests a wide range of wild and domesticated berries and stone fruits. The model captures the observed phenology of D. suzukii at specific locations, as well as the potential geographic distribution and relative favorability across larger regions. The main limiting factor is cold winter temperature in northern areas, though high temperatures and low relative humidity may be limiting in arid areas. The effect of greater cold tolerance in winter morph adults is explored.

Gutierrez A.P., Ponti L., Dalton D.T., 2016. Analysis of the invasiveness of spotted wing Drosophila (Drosophila suzukii) in North America, Europe, and the Mediterranean Basin. Biological Invasions, | Full text free to view

Geographic distribution of  Drosophila suzukii in Europe.

Invasion biology of Drosophila suzukii

May 11, 2016 Leave a comment

The Asian vinegar fly Drosophila suzukii [spotted wing Drosophila (SWD)] has emerged as a major invasive insect pest of small and stone fruits in both the Americas and Europe since the late 2000s. While research efforts have rapidly progressed in Asia, North America, and Europe over the past 5 years, important new insights may be gained in comparing and contrasting findings across the regions affected by SWD. In this review, common themes in the invasion biology of SWD are explored by examining (1) its biology and current pest status in endemic and recently invaded regions; (2) current efforts and future research needs for the development of predictive models for its geographic expansion; and (3) prospects for both natural and classical (=importation) biological control of SWD in invaded habitats, with emphasis on the role of hymenopteran parasitoids. The review concludes that particularly fruitful areas of research should include fundamental studies of its overwintering, host-use, and dispersal capabilities; as well as applied studies of alternative, cost-effective management techniques to complement insecticide use within the integrated pest management framework. Finally, we emphasize that outreach efforts are critical to effective SWD management by highlighting successful strategies and insights gained from various geographic regions.

Asplen M.K., Anfora G., Biondi A., Choi D-S., Chu D., Daane K.M., Gibert P., Gutierrez A.P., Hoelmer K.A., Hutchison W.D., Isaacs R., Jiang Z-L., Kárpáti Z., Kimura M.T., Pascual M., Philips C.R., Plantamp C., Ponti L., Vétek G., Vogt H., Walton V.M., Yu Y., Zappalà L., Desneux N., 2015. Invasion biology of spotted wing drosophila (Drosophila suzukii): a global perspective and future priorities. Journal of Pest Science, 88: 469-494.

Drosophila suzukii (

Agrobiodiversity in a changing world

July 19, 2015 Leave a comment

Exotic species that invade new areas cause economic loss annually nearly tenfold that of natural disasters. The economic impact of such biological invasions has been considerable also in agriculture, with many major agricultural pests being invasive species, which number is expected to increase given the combined action of climate warming and globalization, particularly in the Mediterranean Basin. This region is rich in natural and agricultural biodiversity but also considerably vulnerable to biological invasions that threaten key elements of Mediterranean agro-biodiversity such as the traditional perennial crops grape and olive. Currently, most major threats to grape and olive culture are invasive species – often vector borne diseases so serious that the only control method is removal and destruction of infected crop plants. However, how to assess the potential impact of such invasive threats, and hence how to manage them, remains an unresolved and largely unexplored problem. Gaps exist between theory and management of invasive species, mostly due to a limited ability to assess their ecological and economic impact. Mechanistic process-based demographic approaches such as physiologically-based demographic models (PBDMs) have the capacity to bridge these gaps, as they address many of the shortcomings that affect mainstream methods currently used to assess invasive species under climate change.

Ponti L., Gutierrez A.P., 2015. Climate change and invasive species, with a particular focus on vine and olives. A (bio) diverse world: agro-biodiversity in a changing world, EXPO Milano 2015, Milano, Italy, 6 May 2015.

Risk assessment for tiger mosquito in Europe

July 19, 2015 Leave a comment

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 and climate change scenarios. An index of population abundance is derived in order to investigate the average annual abundance as well as the change in the pattern of population dynamics as a function of the local climatic conditions. Uncertainty affecting model parameters is also considered and the implication on model simulation is evaluated.

Gilioli G., Pasquali S., Ponti L., Calvitti M., Moretti R., Gutierrez A.P., 2015. Modelling the potential distribution and abundance of Aedes albopictus in Europe under climate change. Impact of Environmental Changes on Infectious Diseases, Sitges, Spain, 23-25 March 2015.

Area of potential establishment for the tiger mosquito in Europe under +2 °C climate warming.

Remote sensing and invasive species

March 30, 2015 Leave a comment

A crucial step in evaluating the impact of invasive species is to map changes in their actual and potential distribution and relative abundance across wide regions over an appropriate time span. While direct and indirect remote sensing approaches have long been used to assess the invasion of plant species, the distribution of invasive animals is mainly based on indirect methods that rely on environmental proxies of conditions suitable for colonization by a particular species. The aim of this article is to review recent efforts in the predictive modelling of the spread of both plant and animal invasive species using remote sensing, and to stimulate debate on the potential use of remote sensing in biological invasion monitoring and forecasting.

Rocchini D., Andreo V., Förster M., Garzon-Lopez C.X., Gutierrez A.P., Gillespie T.W., Hauffe H.C., He K.S., Kleinschmit B., Mairota P., Marcantonio M., Metz M., Nagendra H., Pareeth S., Ponti L., Ricotta C., Rizzoli A., Schaab G., Zebisch M., Zorer R., Neteler M., 2015. Potential of remote sensing to predict species invasions – a modeling perspective. Progress in Physical Geography,

Suitability of Europe for Asian tiger mosquito Aedes albopictus based on land surface temperatures remotely sensed via MODIS satellites.

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, | Get a free reprint

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