Flower & Fruit Injury Apple scab on apple (right) Codling moth in apple Left: Western flower thrips feeding injury on impatiens Above: Bean pod mottle virus in soybeans (left) vs uninfected beans (right) Weed Effects • • • • • Weed Groups Algae (aquatic systems) Mosses/liverworts (turf & nurseries) Ferns/horsetails (pastureland, horticultural crops) Gymnosperms (rangeland, forests, long-term notill systems) Angiosperms [monocotyledon & dicotyledon] (annuals, biennials, perennials) Weed Impacts • • • • Competitive yield loss (quantity and quality) Parasitic effects (cf Norris et al., p 23 – 24) Mechanical interference with farm implements Other incidental – Seed contamination – Land valuation – Health & safety (hay fever, toxins, fire hazard) Comparative Biology of Pests Chapter is divided into principal segments Concepts in Pest Population Regulation Dissemination, Invasion, and Colonization Processes Pest Genetics Comparative Biology of Pests • Concepts in Pest Population Regulation Reproduction Fecundity & Fertility Population Generation Time Longevity & Mortality Quiescence and Dormancy Heat Summation & Degree Days Molting & Metamorphosis Life Tables Basic Life Cycle Models Reproduction Sexual Good for IPM Bad for IPM Can manage resistance Mating disrupt possible More plastic, better able to overcome tactics Strain/race geographically specific Can’t overcome effective controls More inoc (path & weed) Faster popn growth (all are reproductive) Asexual Note: Many serious species have both sexual & asexual periods or stages Individual and Population Development Time • Includes: • Fecundity & Fertility Population Generation Time Cycles per Season Longevity and Mortality Affects management response time Management Response Time • The amount of time between when a decision to control a pest is made and when that control takes effect • Primarily used for rescue treatments • Directly affects action thresholds