RAUSHER DEB-9615227 The chemical content of plants affects insect survival and reproduction and thus may influence the size of insect populations. In a phenomenon known as induced resistance, some plants respond to herbivore attack by producing new compounds which negatively affect insect growth and reproduction. Understanding the effects of inducible resistance on insect herbivores is important for understanding herbivore population regulation because the strength of the response may increase as insect populations and insect damage increases. Consequently, inducible resistance may be a negative feed-back mechanism that helps regulate insect populations. The investigator will perform experiments with soybeans and Mexican bean beetles to determine whether induced resistance can regulate insect populations. Soybean cultivars that vary genetically in inducible response will be used to compare the population dynamics of the bean beetle on soybean cultivars with high and low levels of inducible response. The PI will use computer modeling to investigate what conditions make regulation by induced resistance possible. It is important to understand how herbivore populations are regulated because insects strongly affect the yield of commercially important plants. If inducible resistance can control insect populations, agricultural breeders may want to include induced resistance in their breeding programs. Inducible resistance may be preferable to the use of constant levels of plant defense because induced resistance may slow the insect's development of resistance to plant defenses.
