PESTICIDE ISSUES “We need to recognize that pest control is basically an ecological, not a chemical problem” Robert L. Rudd (text, p. 516)

To spray or not to spray… The decision is…. ECONOMIC!

Pesticide Economics Economic threshold—level where economic losses caused by pest damage equal cost of applying a pesticide Spraying beyond threshold… -can increase pest resistance and costs Ever-increasing levels? Pesticide Treadmill Increased pesticide use (above “needed” levels) can also result from: Spraying extra to make fruits/veggies pretty (cosmetic spraying)

INTEGRATED PEST MANAGEMENT I ntegrated P est M anagement (IPM) is an approach to managing pests such as insects, diseases, weeds and animals by integrating appropriate: Physical/Cultivation Biological Chemical …tactics that are safe, profitable and environmentally compatible.

First Level of Pesticide Alternatives: Cultivation practices Crop rotation Tree breaks/plant breaks Polyculture—intercropping, agroforestry, polyvarietal planting Planting “trap crops” Genetic/Cultivated solutions—plants “resistant” to pests/diseases BUT the pests evolve!!

topics/environmentalissues/ipm

Biologically-based Pesticide Alternatives Biological Solutions Natural enemies—ladybugs, parasitic wasps What are pros and cons of this? Good: focuses on target, self-perpetuating, minimize genetic resistance in pests Bad: takes years of research, may be hard to mass produce, can be done incorrectly! What about introducing NON-NATIVE species??

Sex and Hormones Releasing sterilized males into the wild Both work, but costly and time-consuming on research end Developmental stops—releasing hormones into the wild to prevent an insect from developing

Chemical Methods – Two tiers First: Naturally-occuring: Insecticidal soaps, rotenoids, Bt, cayenne pepper Bt – bacillus thuringensis toxin from soil bacteria that is naturally toxic to many insect species. Also in GM corn Only then, as a last resort: Conventional pesticides – Atrazine, organophosphates, carbamates (organo- chlorine compounds like DDT bioaccumulate, biomagnify and are used much less now)

Sources