The authors outline a possible course of events in the evolution of selenium tolerance in the newly discovered diamondback moth. Their overall conclusion is that although selenium hyperaccumulation protects plants from herbivory by some invertebrates, it can give rise to the evolution of unique selenium-tolerant herbivores, thereby providing a "portal" for selenium into the local ecosystem--that is, a pathway by which selenium hyperaccumulation may spread within parts of the food web.
The authors point out that in a broader context, the findings potentially have implications for a number of ways in which selenium accumulation might be utilized in different ecological and agricultural circumstances. Applying selenium to plants may be an efficient way to deter herbivory and improve crop productivity, and if managed carefully, the supplied selenium could give added value to the crop (some evidence suggests that selenium has anticarcinogenic properties). Furthermore, the newly discovered selenium-tolerant moth may be used for biological control of plants that hyperaccumulate selenium in areas where such plants cause poisoning of livestock. In addition, the selenium-hyperaccumulator plant may also be useful for removing and dispersing selenium from polluted water and soil. The authors note that such use of native selenium hyperaccumulators or of selenium-enriched agricultural crops--for environmental cleanup or as a source of anti-carcinogenic selenocompounds--may have ecological implications, as is clear from the apparent rapid evolution of selenium-tolerant insects shown in this study.