## Topics Covered Since Exam 1 ### Chemical ecology * Insects rely heavily on semiochemicals to get information from the environment. * Insects use pheromones for intraspecific communication. There are many types of pheromones: sex pheromones, aggregation pheromones, alarm pheromones, trail-following pheromones, etc. * Synthetic pheromones extensively in insect pest control for monitoring, population reduction (attracticides), and mating disruption. * Insects use kairomones for finding food: host plants, nectar, prey and host insects. ### Mimicry and Camouflage * Batesian mimicry: a non-harmful species (mimic) has evolved to look like a harmful species (model) * Mullerian mimicry: two or more unrelated noxious, or dangerous, organisms exhibit closely similar warning coloration (usually patterns often yellow, red and black stripes) * Camouflage ### Population dynamics * Exponential model * Logistic model * Carrying capacity (k): maximum population size that can be sustained by the environment * r-selected and k-selected species * Lotka-Voltera model for population dynamics of interacting species ### Invasive species * An invasive species is alien and causes harm. * Invasive species readily establish on tropical islands because they have "escaped from natural enemies", weather is benign (no winter, high humidity), and there is usually plenty of food and water. * Fifty percent of Guam's invasive insects belong to Order Hemiptera. ### Applied entomology * Pest control based solely on pesticide application is limited because of pesticide resistance and nontarget effects. * Integrated pest management (IPM): one or more pest control tactics are selected based on knowledge of the current situation gained from pest monitoring. * IPM tactics include pesticide application, sanitation, biological control, physical control, cultural control, and "do nothing". * Economic threshold level (EIL): the population density at which pest control should be initiated to prevent economic damage. * If possible, broad spectrum pesticides should be avoided because they may kill beneficial insects which will lead to an uncontrolled resurgence of pests.