Effects of 15-Acetyl-deoxynivalenol (15-ADON) and Diacetoxyscirpenol (DAS) Mycotoxins on Tribolium castaneum

Two major threats to stored products in the United States and throughout the world are stored product insects and contamination from mycotoxins, which are secondary metabolites produced by fungi, such as Fusarium spp. (Glenn, 2007). Although stored product insects are not associated with negative health impacts when consumed by humans or animals, mycotoxins can negatively impact fertility, reproductive health, growth and development, particularly in livestock (Brake, 1999). Unfortunately, it is difficult to remove mycotoxins from contaminated products and most products have to be destroyed. However, stored product insects routinely feed on products contaminated by mold and may posses detoxification enzymes that could be exploited by the food industry to degrade mycotoxins. To determine whether Tribolium castaneum (red flour beetles) may have resistance to mycotoxins commonly encountered in stored products, such as 15-acetyl-deoxynivalenol (15-ADON) and diacetoxyscirpenol (DAS), we performed bioassays using 10-fold serial dilutions of both purified toxins independently and measured life history parameters, including mortality rates, growth rates, and progeny production. These parameters were compared to insects fed on a control diet to determine whether mycotoxins negatively impacted red flour beetle adults. This allows for an understanding of how individual mycotoxins influence the insects rather than their combinations seen in naturally contaminated mold (Guo, 2014).The results showed no significant impact on any of the life history parameters from the 15-ADON mycotoxin; however, the DAS showed a significant impact on growth rates and progeny production. Furthering the study of the resistance of red flour beetles to mycotoxins may allow us to discover novel enzymes that could be used to degrade mycotoxins contaminating grain, allowing it to be used as animal food and reducing post-harvest losses

A Conceptual Framework for Multi-Regional Climate Change Assessments for International Market Systems with Long-Term Investments

A conceptual framework for climate change assessments of international market systems that involve long-term investments is proposed. The framework is a hybrid of dynamic and static modeling. Dynamic modeling is used for those system components for which temporally continuous modeling is possible, while fixed time slices are used for other system components where it can be assumed that underlying assumptions are held constant within the time slices but allowed to vary between slices. An important component of the framework is the assessment of the “metauncertainty” arising from the structural uncertainties of a linked sequence of climate, production, trade and decision-making models. The impetus for proposing the framework is the paucity of industry-wide assessments for market systems with multiple production regions and long-term capital investments that are vulnerable to climate variations and change, especially climate extremes. The proposed framework is pragmatic, eschewing the ideal for the tractable. Even so, numerous implementation challenges are expected, which are illustrated using an example industry. The conceptual framework is offered as a starting point for further discussions of strategies and approaches for climate change impact, vulnerability and adaptation assessments for international market systems