Trade in live plants has been recognized worldwide as an important invasion pathway for non-native plant pests. Such pests can have severe economic and ecological consequences. Nearly 70%% of ...damaging forest insects and pathogens established in the US between 1860 and 2006 most likely entered on imported live plants. The current regulation of plant imports is outdated and needs to balance the impacts of pest damage, the expense of mitigation efforts, and the benefits of live plant importation. To inform these discussions, we document large increases in the volume and value of plant imports over the past five decades and explain recent and proposed changes to plant import regulations. Two data sources were used to estimate the infestation rate of regulated pests in live plant shipments entering the US, thus allowing evaluation of the efficacy of the current port inspection process.
The increasing demand for a steady, healthy food supply requires an efficient control of the major pests and plant diseases. Current management practices are based largely on the application of ...synthetic pesticides. The excessive use of agrochemicals has caused serious environmental and health problems. Therefore, there is a growing demand for new and safer methods to replace or at least supplement the existing control strategies. Biological control, that is, the use of natural antagonists to combat pests or plant diseases has emerged as a promising alternative to chemical pesticides. The Bacilli offer a number of advantages for their application in agricultural biotechnology. Several Bacillus -based products have been marketed as microbial pesticides, fungicides or fertilisers. Bacillus -based biopesticides are widely used in conventional agriculture, by contrast, implementation of Bacillus -based biofungicides and biofertilizers is still a pending issue.
The evaluation of the potential for newly arrived species to survive and the determination whether a founder population can become established and subsequently spread and cause negative impacts are ...crucial considerations when performing a pest risk assessment in plant health. Climate change has clear consequences concerning the potential range of pests, and their potential for spread and impacts. Despite its importance, no guidance exists to support the evaluation of whether and how climate change should be incorporated into pest risk assessment. This paper reviews how climate change has been considered so far, not only in the area of pest risk assessment but also in other domains and provides guidance on how its incorporation could affect the overall assessment. Furthermore, from this analysis, some possible solutions for incorporating climate change into pest risk assessment are provided, taking into account that its outcomes have profound political, economic, social and environmental implications.
Inclure le changement climatique dans l'évaluation du risque phytosanitaire: pratiques actuelles et perspectives
L'évaluation du potentiel de survie de nouvelles espèces; et la détermination de la possibilité d'établissement et de dissémination d'une population fondatrice et de ses impacts négatifs sont des considérations cruciales lors de la réalisation d'une évaluation du risque phytosanitaire. Le changement climatique a des conséquences évidentes sur la répartition géographique potentielle d'organismes nuisibles ainsi que sur leurs éventuels dissémination et impacts. Malgré son importance, il n'existe aucune directive pour évaluer la pertinence de l'intégration du changement climatique dans l'évaluation du risque phytosanitaire. Cet article examine comment le changement climatique a été pris en compte jusqu'à présent, non seulement dans le domaine de l'évaluation du risque phytosanitaire, mais également dans d'autres domaines, et explique l'impact de son intégration sur l'ensemble de l'évaluation. En outre, à partir de cette analyse, certaines solutions pour intégrer le changement climatique dans l'évaluation du risque phytosanitaire sont fournies, en reconnaissant que le changement climatique aura de profondes implications politiques, économiques, sociales et environnementales.
Включение изменения климата в оценку фитосанитарного риска: текущие практики и перспективы будущего применения
Оценка потенциала выживания новоприбывших видов и определение того, может ли популяция акклиматизироваться, а затем распространиться и вызвать негативные последствия, являются важнейшими факторами при проведении оценки фитосанитарного риска. Изменение климата имеет очевидные последствия в отношении потенциального ареала вредных организмов, а также потенциала их распространения и масштаба наносимого вреда. Несмотря на важность проблемы климатических изменений, в настоящее время не существует четкого руководства, описывающего, следует ли и каким образом включать вопросы изменение климата в оценку фитосанитарного риска. В данной статье приведён обзор того, как проблема изменения климата рассматривалась до настоящего времени в области оценки фитосанитарного риска и в смежных областях, а также рассмотрено, как учёт климатических изменений может повлиять на общую оценку фитосанитарного риска. Кроме того, на основе проведенного анализа предлагаются возможные решения для включения вопросов изменения климата в оценку фитосанитарного риска, с учетом того, что они влекут за собой серьезные политические, экономические, социальные и экологические последствия.
Herbivorous insects use diverse feeding strategies to obtain nutrients from their host plants. Rather than acting as passive victims in these interactions, plants respond to herbivory with the ...production of toxins and defensive proteins that target physiological processes in the insect. Herbivore-challenged plants also emit volatiles that attract insect predators and bolster resistance to future threats. This highly dynamic form of immunity is initiated by the recognition of insect oral secretions and signals from injured plant cells. These initial cues are transmitted within the plant by signal transduction pathways that include calcium ion fluxes, phosphorylation cascades, and, in particular, the jasmonate pathway, which plays a central and conserved role in promoting resistance to a broad spectrum of insects. A detailed understanding of plant immunity to arthropod herbivores will provide new insights into basic mechanisms of chemical communication and plant-animal coevolution and may also facilitate new approaches to crop protection and improvement.
Plants use inducible defence mechanisms to fend off harmful organisms. Resistance that is induced in response to local attack is often expressed systemically, that is, in organs that are not yet ...damaged. In the search for translocated defence signals, biochemical studies follow the physical movement of putative signals, and grafting experiments use mutants that are impaired in the production or perception of these signals. Long-distance signals can directly activate defence or can prime for the stronger and faster induction of defence. Historically, research has focused on the vascular transport of signalling metabolites, but volatiles can play a crucial role as well. We compare the advantages and constraints of vascular and airborne signals for the plant, and discuss how they can act in synergy to achieve optimised resistance in distal plant parts.
Herbivore damage to leaves and other vegetative tissues often stimulates the emission of volatile compounds, suggesting that these substances have a role in plant defense. In fact, ample evidence has ...accumulated in the last few years indicating that volatiles from vegetative plant parts can directly repel herbivores, such as ovipositing butterflies and host-seeking aphids. Volatiles have also been demonstrated to protect plants by attracting herbivore enemies, such as parasitic wasps, predatory arthropods and possibly even insectivorous birds. Even below ground herbivory results in the release of volatiles that attract herbivore enemies. However, plant volatiles are also known to attract enemies of plants. Hence, to determine the true value of these substances in defense, more research is needed especially in natural communities with non-agricultural species.
The expansion of intensive agricultural practices is a major threat to biodiversity and to the delivery of ecosystem services on which humans depend. Local‐scale conservation management strategies, ...such as agri‐environment schemes to preserve biodiversity, have been widely adopted to reduce the negative impacts of agricultural intensification. However, it is likely that the effectiveness of these local‐scale management actions depend on the structure and composition of the surrounding landscape. We experimentally tested the utility of floral resource strips to improve local‐scale biological control of crop pests, when placed within a gradient of moderately simple through to highly complex landscapes. We found that experimental provision of floral resources enhanced parasitism rates of two globally important crop pests in moderately simple landscapes but not in highly complex ones, and this translated into reduced pest abundances and increased crop yield. Synthesis and applications. Our results lend experimental support for the ‘intermediate landscape complexity hypothesis’, which predicts that local conservation management will be most effective in moderately simple agricultural landscapes, and less effective in either very simple landscapes where there is no capacity for response, or in highly complex landscapes where response potential is already saturated. This knowledge will allow more targeted and cost‐effective implementation of conservation biological control programs based on an improved understanding of landscape‐dependent processes, which will reduce the negative impacts of agricultural intensification.
Agronomic intensification has transformed many agricultural landscapes into expansive monocultures with little natural habitat. A pervasive concern is that such landscape simplification results in an ...increase in insect pest pressure, and thus an increased need for insecticides. We tested this hypothesis across a range of cropping systems in the Midwestern United States, using remotely sensed land cover data, data from a national census of farm management practices, and data from a regional crop pest monitoring network. We found that, independent of several other factors, the proportion of harvested cropland treated with insecticides increased with the proportion and patch size of cropland and decreased with the proportion of seminatural habitat in a county. We also found a positive relationship between the proportion of harvested cropland treated with insecticides and crop pest abundance, and a positive relationship between crop pest abundance and the proportion cropland in a county. These results provide broad correlative support for the hypothesized link between landscape simplification, pest pressure, and insecticide use. Using regression coefficients from our analysis, we estimate that, across the seven-state region in 2007, landscape simplification was associated with insecticide application to 1.4 million hectares and an increase in direct costs totaling between $34 and $103 million. Both the direct and indirect environmental costs of landscape simplification should be considered in design of land use policy that balances multiple ecosystem goods and services.
Damage from species of leafminer flies (Agromyzidae: Diptera) on their plant host(s) is caused mostly by internal larval feeding, but also from female oviposition and feeding punctures, which results ...in structural damage, the vectoring of viruses and pathogenic fungi, and the exposure of tissue to secondary infection. Many plants of agricultural and ornamental importance are attacked in the field and in glasshouses, and while fly populations are normally kept in check by hymenopterous parasitoids, they sometimes occur in large enough numbers to affect yield and may destroy entire crops. Species affecting crops may be specialists on one host or a larger number of related hosts, but only 16 species of Liriomyza, Phytomyza and Tropicomyia are truly polyphagous. The threat of these flies is compounded by increasing insecticide resistance and the ease by which polyphagous species can multiply on weeds around growing areas or on alternate crops. All species are also readily spread through trade on their host plant or in soil, causing some species to become globally invasive, with some being of quarantine concern. An overview of agromyzid biology, ecology and agricultural importance is provided, and detailed consideration is given for 26 major pests of special concern. For each of these species, an overview of contemporary knowledge is provided for identification and diagnosis, global distribution, hosts plant(s), host damage, biology, and means of dispersal. To aid in their control, early warning systems, and means of field monitoring and management are provided.
Grafting is an important integrated pest management strategy to manage soilborne pathogens and other pests of solanaceous and cucurbitaceous crops. Important diseases managed by grafting are caused ...by fungal pathogens such as
Verticillium,
Fusarium,
Pyrenochaeta and
Monosporascus; oomycete pathogens like
Phytophthora; bacterial pathogens, particularly
Ralstonia; root knot nematodes and several soil-borne virus pathogens. Rootstocks can include intraspecific selections that utilize specific major resistance genes and interspecific and intergeneric selections that exploit non-host resistance mechanisms or multigenic resistance. Rootstock selection has also been documented to impact foliar pests including pathogens, arthropods and viruses. Over-reliance on specific rootstocks in production systems has led to the emergence of new pathogens or shifts in the host specificity of the pathogen population, emphasizing the need for multi-tactic approaches to manage soilborne pathogens. One advantage and associated challenge of grafting is that rootstock selection for disease management is site specific depending on the presence, population structure and dynamics of the pathogen, as well as edaphic, environmental and anthropogenic factors. The use of grafting as an Integrated pest management tool to manage biotic stress will be most successful when carried out with increasing knowledge about the biology, diversity, and population dynamics of the pathogen or other pests and when complemented with sustainable farming system practices. This review highlights major uses of grafting to manage soilborne pathogens, provides some novel information on managing foliar or other soilborne pests (insects, mites, weeds) and offers discussion on future research and applications.
PDF
