The Coral Triangle and Climate Change: ecosystems, people and societies at risk

The Coral Triangle stretches across six countries in Southeast Asia and the Pacific (Indonesia, Philippines,\ud Malaysia, Papua New Guinea, Solomon Islands and Timor Leste)\ud and is the richest place on earth in terms of biodiversity. In no more than 1% of the Earth’s surface, evolution has produced species and ecosystems that are unrivalled in number, colour and diversity. Within its seas, lie the richest marine communities and ecosystems found anywhere on\ud planet Earth. With over 30% of the world’s coral reefs, including 76% of the world’s reef building corals and over 35% of the world’s coral reef fish species, the Coral Triangle is remarkable and invaluable.\ud \ud This report is a summary of a comprehensive study involving over 20 experts and based on 300 peer-reviewed scientific articles

Changes in plant responses induced by an arthropod influence the colonization behavior of a subsequent herbivore

Background: Plants in nature can be sequentially attacked by different arthropod herbivores. Feeding by one arthropod species may induce plant-defense responses that might affect the performance of a later-arriving herbivorous species. Understanding these interactions can help in developing pest-management strategies. In tomato, the sweet-potato whitefly Bemisia tabaci and the two-spotted spider mite Tetranychus urticae are key pests that frequently cohabit on the same plant. We studied whether colonization by one species can either facilitate or impede later colonization of tomato plants by conspecific or heterospecific individuals. Results: B. tabaci females showed a strong preference for and increased oviposition on plants previously colonized by conspecifics. In contrast, plants infested with T. urticae repelled B. tabaci females and reduced their oviposition rate by 86%. Although females of T. urticae showed no preference between conspecific-infested or uninfested plants, we observed a 50% reduction in the number of eggs laid on conspecific-infested plants. Both herbivorous arthropods up-regulated the expression of genes involving the jasmonic acid and abscisic acid pathways, increasing emissions of fatty-acid derivatives, but only B. tabaci increased the expression of genes related to the salicylic acid pathway and the total amount of phenylpropanoids released. Terpenoids were the most abundant compounds in the volatile blends; many terpenoids were emitted at different rates, which might have influenced the arthropods' host selection. Conclusion: Our results indicate that B. tabaci infestation facilitated subsequent infestations by conspecifics and mites, while T. urticae infestation promoted herbivore-induced resistance. Based on both the molecular and behavioral findings, a novel sustainable pest-management strategy is discussed