Pests and Pollinators

The Terms: Pests and WeedsPest: Any organism that damages crops that are valuable to us.

Weed: any plant that competes with our crops.

We have developed thousands of chemical pesticides.There are thousands of artificial chemicals

developed to kill pests.InsecticidesHerbicidesFungicides

Pests Evolve Resistance to Pesticides

Resistant PestsGreen peach AphidColorado potato

beetleDiamondback moth

Biological Control Pits One Organism Against AnotherBiological control/biocontrol: “the enemy of

one’s enemy is one’s friend”.

Biological Control Agents Themselves May Become Pests

Biocontrol“should be used with our eyes wide open—

and as a last resort”---Daniel Simberloff

“only a small percentage of efforts have resulted in demonstrable nontarget effects, and perhaps fewer than 10% of these effects were substantial.”---two British scientists reviewing cases from 2000

Integrated Pest management combines Biocontrol and Chemical Methods

Integrated Pest Management (IPM): Numerous techniques are integrated to achieve long-term suppression of pests, including biocontrol, use of chemicals when added, close monitoring of populations, habitat alteration, crop rotation, transgenic crops, alternative tillage methods, and mechanical pest removal.

We depend on insects to pollinate cropsPollination: the process by which male sex

cells of a plant (pollen) fertilize female sex cells of plant

PollinatorsCultivars Percentage of Plants

Cultivated by Them

Bees 73%

Flies 19%

Wasps 5%

Beetles 5%

Moths and Butterflies 4%

Bats 6.5%

Birds 4%

U.S. Stamp Depicting Pollinators