Few things in a gardener's world can be more irritating than pests in a vegetable garden. Sometimes it seems like a never-ending battle every season. Some pests are innocuous and easy to eradicate. Others can destroy entire crops. There are many products that are effective in the fight against vegetable garden pests.
Neem is nothing more than a vegetable oil, processed from the seeds of Azadirachta indica, an evergreen tree that is native to Southeast Asia. Neem oil is effective in controlling garden pests and has no adverse effects on beneficial organisms. Neem oil is non-toxic and effective.
Rotenone doesn't seem to be able to discern the good bugs from the bad and just wipes them all out. It breaks down quickly in the soil, leaving little or no adverse effect on the environment. It does, however, kill fish in addition to insects, and there are ongoing studies to determine if there is a link between the use of rotenone and Parkinson's disease. If you use rotenone in the garden, wear gloves and avoid breathing the dust.
Pyrethrin is an organic compound extracted from certain chrysanthemum plants. Pyrethrins are known as contact poisons in that, within minutes, they will penetrate the nerve system of the insect, rendering it paralyzed. Like all insecticides, organic or inorganic, inhaling pyrethrin can cause upper respiratory problems such as asthma, headaches and other physical symptoms.