One of the main risks associated to transgenic crops expressing Bacillus thuringiensis (Bt) toxins is the evolution of pest resistance. The adoption of Bt crops requires environmental risk assessment that includes resistance risk estimation, useful for definition of resistance management strategies aiming to delay resistance evolution. In this context, resistance risk is defined as the probability of the Bt toxin resistance allele frequency (RFreq) exceeding a critical value (CriticalFreq). Mathematical simulation models have been used to estimate (RFreq) over pest generations. In 1998, Caprio developed a deterministic simulation model with few parameters that can be used to obtain RFreq point estimates from point information about model parameters and decision variables involved in that process. In this work, the resistance risk was estimated using Caprio´s model, by incorporating uncertainty to the resistance allele initial frequency (InitialFreq). The main objective was to evaluate the influence of different probability distribution functions on the risk estimates. The simulation results showed that the influence of InitialFreq input distributions on the risk estimates changes along pest generations. The risk estimates considering input Normal distribution for InitialFreq are similar to those ones obtained considering Triangular distribution if their variances are equal. The use of Uniform distribution instead the Normal or Triangular due to the lack of information about InitialFreq leads to an overestimation of risk estimates for the initial generations and sub estimation for the generations after the one for which the critical frequency is achieved.

The European and Mediterranean Plant Protection Organisation (EPPO) aims to prevent the entry and spread of organisms harmful to both cultivated and wild plants. Basing their activities on those of the Convention on Biological Diversity and the International Plant Protection Convention, the EPPO is developing a new concept for invasive alien species and ‘plants as pests’. A pest risk analysis is necessary in most cases to identify which organisms should be regulated and how. In accordance with the International Plant Protection Convention, an EPPO risk assessment standard exists for this purpose which has now been revised to be applicable also to potentially invasive alien plants and assess the effects they pose to the uncultivated environment. In 2003, the EPPO sent a questionnaire to its 44 member states asking for plants which have been intentionally or unintentionally introduced and are considered invasive. The member countries reported hundreds of species, of which 42 were selected for further assessment. This may result in recommendations for regulations and measures against the introduction and spread of all or some of these plants.

The European and Mediterranean Plant Protection Organisation (EPPO) aims to prevent the entry and spread of organisms harmful to both cultivated and wild plants. Basing their activities on those of the Convention on Biological Diversity and the International Plant Protection Convention, the EPPO is developing a new concept for invasive alien species and 'plants as pests'. A pest risk analysis is necessary in most cases to identify which organisms should be regulated and how. In accordance with the International Plant Protection Convention, an EPPO risk assessment standard exists for this purpose which has now been revised to be applicable also to potentially invasive alien plants and assess the effects they pose to the uncultivated environment. In 2003, the EPPO sent a questionnaire to its 44 member states asking for plants which have been intentionally or unintentionally introduced and are considered invasive. The member countries reported hundreds of species, of which 42 were selected for further assessment. This may result in recommendations for regulations and measures against the introduction and spread of all or some of these plants. © Springer-Verlag 2004.

The aim of the European and Mediterranean Plant Protection Organisation (EPPO) is to prevent the entry and spread of organisms harmful to cultivated as well as to wild plants. Following to the activities of the Convention on Biological Diversity and the International Plant Protection Convention (IPPC), EPPO is developing a new working programme on invasive alien species and “pest plants”. To identify the need for regulation of organisms which may be harmful to plants, a pest risk analysis is necessary in most cases. In accordance with the IPPC, an EPPO standard exists to assess risks of „traditional quarantine pests“, which is now revised in order to be also applicable to potentially invasive plants and to the evaluation of impacts invasive alien species relevant for plants pose to the uncultivated environment. In 2003, EPPO has sent a questionnaire to its member states asking for plants which have been introduced into EPPO countries and are considered as invasive or potentially invasive. The member states reported hundreds of plant species, of which 42 were selected for further assessment. The assessments may result in listing of the plants in the existing EPPO lists and recommendations for regulations and measures against the introduction and spread of these or some of these plants. Also plants not yet present in the EPPO region but potentially posing a risk if introduced will be assessed.

Chickpea, Cicer arietinum, is the third most important grain legume crop in the world, with India being the largest producer. Insect pests are a major constraint to chickpea production. In India, the legume pod borer Helicoverpa armigera is the major insect pest of chickpeas. However, sap-sucking insects that act as vectors for viral diseases and bruchid beetles in storage are also considered important pests. Here we give an overview over the different management options to control these pests. There is a growing interest in the genetic modification of crops to enhance their resistance against insect pests. Here we present the state-of-the-art of chickpea transformation and give an overview on the available insecticidal genes that could be deployed to increase insect resistance in chickpea. Prior to commercialization, transgenic crops have to be assessed for their effects on the environment including the possible impact on non-target arthropods, many of which are important for biological pest control. Therefore, the arthropod-food web in the Indian chickpea system is described. Possible routes through which entomophagous insects could be exposed to insecticidal proteins expressed by genetically modified chickpeas are discussed, and species that could be selected for pre-release risk assessment are recommended.

The use of recombinant DNA technology to develop genetically-modified crops is considered as a major breakthrough for agriculture by many scientists. However, some scientists, and an even larger proportion of the general public, are sceptical about the advantages and are even more concerned about the potential risk of this new technology. To evaluate this novel technology, cost-benefit analyses are needed in which the real risks are measured and judged against the benefits. A tiered risk assessment scheme is described herein. This allows comparisons to be made with other insect-control technologies (e.g. insecticides) and risks to be determined, rather than only hazards being identified. Recombinant DNA technology could allow plants to be designed that are well suited for use alongside biological control programmes. Unfortunately, plant breeders have continued to attempt to breed for total resistance, and biocontrol specialists have ignored the role of the plant in ensuring successful foraging behaviour by insect natural enemies. Although some scientists have highlighted the need to consider both the bottom-up (plant defence) and top-down (biocontrol) control of insect pests, there have been few serious attempts to combine these approaches. As more is understood about the proximate and ultimate causes of direct and indirect defences, the potential exists for engineering plants that combine both strategies. This new possibility for controlling insect pests, which will combine both 'nature's' own defences with man's ingenuity, may stack the odds in our favour in the continual struggle against insect pests.

There is no evidence that Pyrenophora semeniperda, the causal agent of leaf spotting in many annual and perennial grasses, currently occurs in Europe or Asia. However, there is potential phytosanitary concern that the importation of infected commodities could result in the introduction of this fungus into Eurasia, putting crops at risk and possibly resulting in economic losses. To assist in assessing the risk of geographic range extension of P. semeniperda, an analysis was undertaken to estimate the potential global distribution of this species, based on climatic suitability. Geographic distribution data for P. semeniperda in part of its current range were used to fit parameter values in a CLIMEX pest risk assessment model, and the remaining distribution data were used to validate the model. The CLIMEX model correctly predicts that virtually all locations where P. semeniperda has been found are climatically suitable. Only five locations worldwide where the fungus was recorded present are predicted as being unsuitable. These "outliers" may have been transient populations occurring during a favorable season and then dying out. Exploratory adjustments of the model to accommodate these records created unsatisfactory distortions in the projected climatic suitability surfaces, extending the suitable climatic zone beyond well-established traditional range boundaries. We are therefore confident that the model is credibly predicting the potential distribution of P. semeniperda worldwide. The CLIMEX model suggests that P. semeniperda could potentially extend its range throughout Europe and temperate regions of Asia, Africa, and South America. Our heavy reliance upon geographic data to build this CLIMEX model departs from most previous published examples in plant pathology, which have depended primarily upon experimentally derived physiological data to estimate model parameters. The use of geographic data to infer climate parameters is popular in CLIMEX models of weeds and arthropod pests and can provide decision-makers with early risk assessments of potential pathogen invasions, particularly where the pathogens have long, or difficult-to-study, lifecycles.

Transgenic Bt maize carries a Bacillus thuringiensis toxin which is effective against larva of the European corn borer, Ostrinia nubilalis. The objective of using Bt maize is to reduce the use of pesticides and to develop sustainable pest control methods against O. nubilalis. The evaluation of potential side effects of transgenic crops on beneficial nontarget organisms such as parasitoid hymenopterans is of growing importance. The species Trichogramma brassicae is a naturally occurring enemy of the European corn borer. The effects of transgenic maize plant food sources were tested on adults of T. brassicae. The experiments followed the principles of the IOBC/WPRS testing guidelines with minor modifications. The following maize cultivars were tested and compared in the laboratory: Pactol CB (Bt 176) and Novelis (Mon 810) and the respective non-transformed cultivars Pactol and Nobilis. Groups of T. brassicae were exposed to the different maize food sources into glass cages: pollen, honeydew from Sitobion avenae aphids and phloem sap. The rate of parasitism of the European corn borer by T. brassicae was calculated as eggs per female and comparisons were made between Bt, non-Bt food sources and control. With pollen, the parasitism per female was 18.923.36 eggs for control, 22.562.24 eggs for Pactol CB (Bt 176), 18.622.27 eggs for Pactol (non-Bt), 15.543.15 eggs for Novelis (Mon 810) and 24.531.93 eggs for Nobilis (non-Bt). When exposed to phloem sap from stem tissue, parasitism was 22.464.60 eggs for control, 16.985.82 for Pactol CB (Bt 176), 14.072.54 for Pactol (non-Bt), 14.924.08 for Novelis (Mon 810) and 14.341.88 for Nobilis (non-Bt). The highest parasitism with maize food sources was reached with honeydew on leaves, with 25.733.62 eggs for control, 30.342.43 for Pactol CB (Bt 176), 34.533.67 for Pactol (non-Bt), 29.682.44 for Novelis (Mon 810) and 35.503.33 for Nobilis (non-Bt). In all the experiments, no significant differences were found between Bt and non-Bt maize. There was no reduction of parasitism. The tested Bt maize cultivars Bt176 and Mon810 can be classified as "harmless" (category 1) to T. brassicae parasitoid wasps. In the present study, the testing method and the indicator organism of the genus Trichogramma were shown to be suitable for future risk assessment and monitoring of transgenic crops.

Methyl iodide (MeI) is a promising alternative to methyl bromide in soil fumigation. The pest-control efficacy and ground water contamination risks of MeI as a fumigant are highly related to its gas-phase distribution and leaching after soil application. In this study, the distribution and leaching of MeI in soil following shank injection and subsurface drip application were investigated. Methyl iodide (200 kg ha⁻¹) was directly injected or drip-applied at a 20-cm depth into Arlington sandy loam (coarse-loamy, mixed, thermic Haplic Durixeralfs) columns (12-cm i.d., 70-cm height) tarped with virtually impermeable film. Concentration profiles of MeI in the soil air were monitored for 7 d. Methyl iodide diffused rapidly after soil application, and reached a 70-cm depth within 2 h. Relative to shank injection, drip application inhibited diffusion, resulting in significantly lower concentration profiles in the soil air. Seven days after MeI application, fumigated soil was uncapped, aerated for 7 d, and leached with water. Leaching of MeI was significant from the soil columns under both application methods, with concentrations of >10 μg L⁻¹ in the early leachate. The leaching was greater following shank injection than drip application, with an overall potential of 33 g ha⁻¹ for shank injection and 19 g ha⁻¹ for drip application. Persistent residues of MeI remaining in soils after leaching were 50 to 240 ng kg⁻¹, and the contents were slightly higher following shank injection than drip application. The results suggest that fumigation with MeI may pose a risk of ground water contamination in vulnerable areas.