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

Integrated Pest Management (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 Adjusting planting times Planting “trap crops” Polyculture—intercropping, agroforestry,

polyvarietal planting Genetic/Cultivated solutions—plants

“resistant” to pests/diseases BUT the pests evolve!!

Biologically-based Pesticide Alternatives

Biological Solutions Natural enemies—ladybugs, parasitic wasps,

pest diseases What are pros and cons of this? Good: focuses on target, self-perpetuating,

minimize genetic resistance in pests Bad: takes years of research, may not be

mass-produced, can be done incorrectly!

What about introducing NON-NATIVE species??

More Biologically-based Pesticide Alternatives Bio-pesticide examples:

from chrysanthemums

Bt – bacillus thuringensis toxin from soil bacteria that is naturally toxic to many insect species.

These pesticides can be used in organic farming.

Sex and Hormones

“Sex police”— 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

Only then, as a last resort: Conventional pesticides – Round-up,

Atrazine, organophosphates, carbamates* (organochlorine compounds like DDT bioaccumulate, and are used much less now)

Like polyculture, IPM is more labor-intensive Includes:

Prevention Monitoring, Identification; then Various options for control

Sources

http://www.scitopics.com/Integrated_Pest_Management.html http://www.capitalgroundwater.org/h2oquiz/businesspesticide.shtml