Thursday, May 12, 2016

Invasion biology of Drosophila suzukii

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. http://dx.doi.org/10.1007/s10340-015-0681-z

Drosophila suzukii (http://www.terraevita.it/drosophila-suzukii-danni-e-contromisure/).

Thursday, November 26, 2015

PBDMs for evidence-based pest risk assessment

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.

Wednesday, November 18, 2015

New agroecology book in Italian

Agroecology: a viable agricultural path for a planet in crisis. It is now clear that humanity needs an alternative agricultural development paradigm, one that encourages more ecologically, biodiverse, resilient, sustainable and socially just forms of agriculture. The basis for this new systems are the myriad of ecologically based agricultural styles developed by over a billion smallholders, family farmers and indigenous people on hundreds of millions of small farms which currently produce most of the global agricultural output for domestic consumption largely without agrochemicals. Agroecology is this paradigm: a dialogue between traditional agricultural knowledge and modern agricultural science that uses ecological concepts and principles for designing and managing sustainable agroecosystems in which external inputs are replaced by natural processes such as natural soil fertility and biological control. This book explains why agroecology is the most robust food provisioning pathway for humanity to take in the twenty-first century under current and predicted and difficult climate, energy, financial and social scenarios.

Altieri M.A., Nicholls C.I., Ponti L., 2015. Agroecologia: una via percorribile per un pianeta in crisi. Edagricole, Bologna. 336 pp. | Get book from publisher


Friday, August 28, 2015

Indian cotton: weather, yields and suicides

Cotton with coevolving pests has been grown in India for more than 5000 years. Hybrid cotton was introduced in the 1970s with increases in fertilizer and in insecticide use against pink bollworm that caused outbreaks of bollworm. Hybrid Bt cotton, introduced in 2002 to control bollworm and other lepidopteran pests, is grown on more than 90 % of the cotton area. Despite initial declines, year 2013 insecticide use is at 2000 levels, yields plateaued nationally, and farmer suicides increased in some areas. Biological modeling of the pre-1970s cotton/pink bollworm system was used to examine the need for Bt cotton, conditions for its economic viability, and linkage to farmer suicides. Yields in rainfed cotton depend on timing, distribution, and quantity of monsoon rains. Pink bollworm causes damage in irrigated cotton, but not in rainfed cotton unless infested from irrigated fields. Use of Bt cotton seed and insecticide in rainfed cotton is questionable. Bt cotton may be economic in irrigated cotton, whereas costs of Bt seed and insecticide increase the risk of farmer bankruptcy in low-yield rainfed cotton. Inability to use saved seed and inadequate agronomic information trap cotton farmers on biotechnology and insecticide treadmills. Annual suicide rates in rainfed areas are inversely related to farm size and yield, and directly related to increases in Bt cotton adoption (i.e., costs). High-density short-season cottons could increase yields and reduce input costs in irrigated and rainfed cotton. Policy makers need holistic analysis before new technologies are implemented in agricultural development.

Gutierrez A.P., Ponti L., Herren H.R., Baumgärtner J., Kenmore P.E.. 2015. Deconstructing Indian cotton: weather, yields, and suicides. Environmental Sciences Europe, 27: 12. http://dx.doi.org/10.1186/s12302-015-0043-8 | Open access

Simulated phenology of cotton fruiting and pink bollworm in irrigated and rainfed cotton during 2005. The movement of adults to rainfed cotton during late summer is indicated by the broad arrow.