Environmental Science 1021F/G Lecture Notes - Lecture 6: Malaria, Biological Pest Control, Biomimetics
19 Apr 2018
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Pest: unwanted organism that interferes with human activities; subjective. A weed is a plant who"s virtues have no yet been discovered . 100 species (1%) cause 90% of the damage. Disturbs predator-prey cycles in natural ecosystems and polycolture. Types: insecticides block reproduction, airways, nervous system (used to control insects, herbicides disrupt plant growth and metabolism (control weeds, fungicides (reduce fungal growth, rodenticides (rodents- rodents carry disease and can contaminate grain) Crop rotation, vary planting times, plant diversity, hedgerows: first generation (have been using for a very long time) Sulphur, lead, arsenic, mercury (don"t use anymore bc it is toxic) Nicotine sulphate, pyrethrum, rotenone: based on plants natural instincts , second generation. Synthetic organic compounds (eg. ddt), broad- and narrow-spectrum, persistence reduction (reducing how long that pesticide/chemicals stay in the environment), some natural. Increase food supplies and profits; lower costs: saves human lives malaria, bubonic plague, typhus, work faster and better than alternatives, health risk *may* be insignificant compared to benefits.
