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This paper provides recommendations on experimental design for early-tier laboratory studies used in risk assessments to evaluate potential adverse impacts of arthropod-resistant genetically engineered (GE) plants on non-target arthropods (NTAs). While we rely heavily on the currently used proteins from Bacillus thuringiensis (Bt) in this discussion, the concepts apply to other arthropod-active proteins. A risk may exist if the newly acquired trait of the GE plant has adverse effects on NTAs when they are exposed to the arthropod-active protein. Typically, the risk assessment follows a tiered approach that starts with laboratory studies under worst-case exposure conditions; such studies have a high ability to detect adverse effects on non-target species. Clear guidance on how such data are produced in laboratory studies assists the product developers and risk assessors. The studies should be reproducible and test clearly defined risk hypotheses. These properties contribute to the robustness of, and confidence in, environmental risk assessments for GE plants. Data from NTA studies, collected during the analysis phase of an environmental risk assessment, are critical to the outcome of the assessment and ultimately the decision taken by regulatory authorities on the release of a GE plant. Confidence in the results of early-tier laboratory studies is a precondition for the acceptance of data across regulatory jurisdictions and should encourage agencies to share useful information and thus avoid redundant testing.

BackgroundHoney bees (Apis mellifera L.) are the most important pollinators of many agricultural crops worldwide and are a key test species used in the tiered safety assessment of genetically engineered insect-resistant crops. There is concern that widespread planting of these transgenic crops could harm honey bee populations.Methodology/Principal FindingsWe conducted a meta-analysis of 25 studies that independently assessed potential effects of Bt Cry proteins on honey bee survival (or mortality). Our results show that Bt Cry proteins used in genetically modified crops commercialized for control of lepidopteran and coleopteran pests do not negatively affect the survival of either honey bee larvae or adults in laboratory settings.Conclusions/SignificanceAlthough the additional stresses that honey bees face in the field could, in principle, modify their susceptibility to Cry proteins or lead to indirect effects, our findings support safety assessments that have not detected any direct negative effects of Bt crops for this vital insect pollinator.

The Western Corn Rootworm, Diabrotica virgifera (WCR; Coleoptera: Chrysomelidae), is a serious pest of maize, causing approximately one billion dollars a year in losses and control costs. The insect has become resistant to several chemical controls and growers have asked for a control solution based on genetically-enhanced resistant varieties. Key to the production of genetically-enhanced germ plasm is the ability to use artificial diets for bioassays to identify proteins with activity against the target insect. However, artificial diets currently used for WCR bioassay do not support good WCR larval development because they were developed and optimized for the Southern Corn Rootworm (SCR). The present study was conducted to understand the nutritional physiology of WCR by altering the dietary constituents of a SCR diet and measuring the subsequent effects on WCR growth. Alteration of most dietary constituents had surprisingly little effect on WCR larval growth. The most significant factors affecting WCR growth on artificial diet were removal of formalin, addition of plant adjuvant, and adjustment of dietary pH to 9.0. These dietary changes resulted in larval WCR growth rates that were nearly double those in standard SCR rootworm diets. In some cases, WCR larvae fed on the improved diet obtained larval masses approaching those of larvae fed on maize roots.

species should be representative of valued taxa or functional groups that are most likely to be exposed to the arthropod-active compound in the field; and (iii) Availability and reliability: suitable life-stages of the test species must be obtainable in sufficient quantity and quality, and validated test protocols must be available that allow consistent detection of adverse effects on ecologically relevant parameters. Our proposed approach ensures that the most suitable species are selected for testing and that the resulting data provide the most rigorous test of the risk hypothesis of no adverse effect in order to increase the quality and efficiency of ERAs for cultivation of GE crops.

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In the interest of identifying new leads that could serve as prototype agrochemical agents, 18 structurally diverse marine-derived compounds were examined for insecticidal, herbicidal, and fungicidal activities. Several new classes of compounds have been shown to be insecticidal, herbicidal, and fungicidal, which suggests that marine natural products represent an intriguing source for the discovery of new agrochemical agents.

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