Effects of induced plant defenses: the role of chemical elicitors on herbivore and...
| Grant number: | 11/17708-0 |
| Support type: | Regular Research Grants |
| Duration: | April 01, 2012 - March 31, 2014 |
| Field of knowledge: | Biological Sciences - Ecology |
| Principal Investigator: | Jose Roberto Trigo |
| Grantee: | Jose Roberto Trigo |
| Home Institution: | Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil |
| Assoc. researchers: | Daniela Rodrigues ; Eduardo Leite Borba ; Lucas Augusto Kaminski ; Paulo Cesar Muniz de Lacerda Miranda ; Rodrigo Cogni |
Abstract
Plants and herbivores have been shaped by strong selective pressures exerted by their natural enemies, which may be responsible for the development of a vast array of defenses in these organisms. To compensate their immobility plants have evolved particular strategies to defend themselves against these enemies. Many kinds of plant defenses are common in nature, as physical (such as non glandular tricomas, spines, and tough leaves), toxic and distasteful secondary compounds, and the attraction of natural enemies of herbivorous insects via rewards or chemical cues. Among herbivorous insects several strategies are utilized to avoid the attack of predators and parasitoids: camouflage, shelters, morphological (e.g. spines, secretions, modified organs) and behavioral defenses (e.g. escape, retaliation), and chemical defenses, which are generally sequestered from host plants. Focusing this approach, the present proposal aims to study chemical defenses in neotropical plants and insects. The studies have been developed in the following multitrophic systems: (1) plants belonging to Crotalaria genus (Leguminosae), their specialist herbivore, the arctiid moth Utetheisa ornatrix (Lepidoptera: Arctiidae) and their predators, (2) Ipomoea carnea fistulosa (Convolvulaceae), their specialist herbivores, the tortoise beetles (Cassidiane: Chrysomelidae), and their predators, egg parasitoids, (3) Asclepias curassavica (Apocynaceae: Asclepiadoideae), their specialist herbivores, the danaine butterfly Danaus erippus (Nymphalidae), and the aphid Aphis nerii (Hemiptera: Aphididae), and (4) several tritrophic interactions among Lycaenidae butteflies, treehoppers and other hemipterans, their host plants, and tending ants. In the three first trophic systems, the main question is how pirrolizidine alkaloids, polyhydroxylated alkaloids and sesquiterpenes, and cardenolides and phenolic compounds, respectively, take part of these interactions. In the latter system, the main interesting point is to study how cuticular hydrocarbons protect the insects, via chemical camouflage, against tending ants. (AU)