|
 |
 |
|
Destroys Plants Useful: In agriculture a pest is any organism that damages or destroys plants useful to man and the term is taken to apply to harmful insects, mammals and birds. Crops also suffer from micro-organisms that cause disease and competing wild plants or weeds.
The important groups of pesticides are insecticides, fungicides and nematicides - for the eelworms which are microscopic nematodes feeding on plant roots. Herbicides are chemicals used for weed control. In tropical and subtropical areas of the world it is the insecticides that tend to be more important. But in the USA (which uses as much agricultural chemicals as the rest of the world together) herbicides are more widely applied than pesticides.
Beetles feed on aphids and scale insects. Keep constant supply of aphid-infested plants in cage; keep plants fresh by moistening soil.
As soon as eggs are deposited, release adults. As soon as eggs hatch, supply larvae with plenty of aphids. The more abundant the food,the more rapidly the larvae grow. When they are ready to pupate, larvae usually crawl from plants and hang on sides of screen. When adults emerge, they should be liberated.
United States west of the Great Plains; similar species in eastern states
In ponds with abundant vegetation; often under street lights during warm summer evenings
Economic position: Larva often destroys young fish, sometimes destructive in fish hatcheries
Adult: Large (1% inches long); body oval, smooth, dull green; entire margin of prothorax (forward section of thorax) and sides of elytra (wing covers) yellow; third pair of legs long, strong, flattened, and adapted for swimming (used as oars); rests head downward from surface of water; flies readily.
The clearing of rainforest destroys a vast and complex ecosystem, with serious consequences for food production and climate, not only locally but worldwide. |
|
|
| |
|
|
|
|
