Key Concepts Types and characteristics of pesticides Pros and cons of using pesticides Pesticide regulation in the US Alternatives to chemical pesticides
Pests Compete with humans for food Invade lawns and gardens Destroy wood in houses Spread disease Are a nuisance May be controlled by natural enemies
Pesticides: Types Chemicals that kill undesirable organisms Insecticides Herbicides Fungicides Rodenticides See Table 23-1 p. 520
First Generation Pesticides Primarily natural substances Sulfur, lead, arsenic, mercury Plant extracts: nicotine, pyrethrum
Second Generation Pesticides Primarily synthetic organic compounds Broad-spectrum agents Narrow-spectrum agents See Table 23-1 p. 520 Persistence in the environment
The Case for Pesticides Save human lives Increase food supplies and lower costs Work better and faster than alternatives Health risks may be insignificant compared to benefits Newer pesticides are becoming safer New pesticides are used at lower rates
Characteristics of an Ideal Pesticide Affects only target pests Harms no other species Breaks down quickly in the environment No genetic resistance Be more cost-effective than doing nothing
The Case Against Pesticides Genetic resistance Can kill non-target and natural control species Can cause an increase in other pest species The pesticide treadmill Pesticides do not stay put Can harm wildlife Potential human health threats
Pesticide Regulation in the United States Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Tolerance levels EPA Evaluation of chemicals Inadequate and poorly enforced Food Quality Protection Act (FQPA)
Other Ways to Control Pests Economic threshold Adjusting cultivation practices Use genetically-resistant plants Biological pest control Insect birth control Hormones and pheromones Ionizing radiation Hot water
Integrated Pest Management Ecological system approach Reduce pest populations to economic threshold Field monitoring of pest populations Use of biological agents Chemical pesticides are last resort
Why is Integrated Pest Management not More Widely Used? Requires expert knowledge Slower than conventional pesticides Initial costs may be high Hindered by government subsidies Requires expert knowledge Slower than conventional pesticides Initial costs may be high Hindered by government subsidies