U.S. EPA regulation of plant-incorporated protectants: assessment of impacts of gene flow from pest-resistant plants

Septicaemia of subterranean termites Coptotermes curvignathus caused by disturbance of bacteria isolated from termite gut and its foraging pathways

Microbial pathogens continue to attract a great deal of attention to manage the termite population. Every bacterium has its own mode of action and in fact, the mechanisms used by bacteria to attack termites remain elusive at the moment. Hence, the objective of this study was to evaluate the susceptibility of subterranean termites Coptotermes curvignathus to opportunistic pathogens using culturable aerobic bacteria isolated from the termite gut and its foraging pathways. Bacterial suspensions were prepared in concentrations of 103, 106 and 109 colony-forming units (CFU) ml-1 and introduced to the termites via oral-contact and physical contact treatment. The data show that contact method acted slower and gave lower mortality, compared to the oral-contact method. Coptotermes curvignathus were highly susceptible to Serratia marcescens and Pseudomonas aeruginosa. Serratia marcescens showed the highest mortality percentage of 68% and 54% at bacterial concentration of 109 CFU ml-1 via oral-contact and contact method, respectively. Serratia marcescens was also defined as the bacteria with the highest ability to induce the high mortality of C. curvignathus with the lowest concentration of bacterial suspension at a given time under laboratory condition. The results of this study indicate that P. aeruginosa and S. marcescens in particular may be attractive candidates worth further examination as a possible biocontrol agent against C. curvignathus in the field and to evaluate environmental and ecological risks of the biocontrol.

Applying gene flow science to environmental policy needs: a boundary work perspective

One application of gene flow science is the policy arena. In this article, we describe two examples in which the topic of gene flow has entered into the U.S. national environmental policymaking process: regulation of genetically engineered crops and clarification of the jurisdictional scope of the Clean Water Act. We summarize both current scientific understanding and the legal context within which gene flow science has relevance. We also discuss the process by which scientific knowledge has been synthesized and communicated to decision-makers in these two contexts utilizing the concept of 'boundary work'. Boundary organizations, the work they engage in to bridge the worlds of science, policy, and practice, and the boundary objects they produce to translate scientific knowledge existed in both examples. However, the specific activities and attributes of the objects produced varied based on the needs of the decision-makers. We close with suggestions for how scientists can contribute to or engage in boundary work with policymakers.

Comparing conventional and biotechnology-based pest management

Pest management has changed dramatically during the past 15 years by the introduction of transgenes into crops for the purpose of pest management. Transgenes for herbicide resistance or for production of one or more Bt toxins are the predominant pest management traits currently available. These two traits have been rapidly adopted where available because of their superior efficacy and simplification of pest management for the farmer. Furthermore, they have substantially reduced the use of environmentally and toxicologically suspect pesticides while reducing the carbon footprint of pest management as reduced tillage became more common, along with fewer trips across the field to spray pesticides. The most successful of these products have been glyphosate-resistant crops, which cover approximately 85% of all land occupied by transgenic crops. Over-reliance on glyphosate with continual use of these crops has resulted in the evolution of highly problematic glyphosate-resistant weeds. This situation has resulted in some farmers using weed management methods similar to those used with conventional crops. Evolution of resistance has not been a significant problem with Bt crops, perhaps because of a mandated resistance management strategy. Transgenic crops with multiple genes for resistance to different herbicides and resistance to additional insects will be available in the next few years. These products will offer opportunities for the kind of pest management diversity that is more sustainable than that provided by the first generation of transgenic crops.