Neem Oil Insecticide
Neem compounds called ‘limonoids’ make it a effective insecticide, pesticide and fungicide. The most significant liminoids found in neem with proven ability to block insect growth are: azadirachtin, salanin, meliantriol and nimbin. Azadirachtin is currently considered as neem’s main agent for controlling insects. It appears to cause 90% of the effect on most pests.
It does not kill insects immediately – instead it both repels and disrupts their growth and reproduction. Research over the past years has shown that it will repel or reduce the feeding of many species of pest insects as well as some nematodes. In fact, it is so potent that a mere trace of its presence prevents some insects from even touching plants.
Certain hormones are necessary for growth and development of insects. These hormones control the process of metamorphosis as the insects pass from larva to pupa to adult. Azadirachtin blocks those parts of the insect’s brain that produce these vital hormones. As a result, insects are unable to molt. It is through these subtle hormonal effects that this important compound of neem breaks the life cycle of insects. The insect populations decline drastically as they become unable to reproduce.
Neem oil insecticides can deter insects in the following ways:
Neem Oil Insecticides are generally harmless to most insect eaters, humans and other mammals, with the exception of certain marine life such as crabs, lobsters, fishes and tadpoles.
Make Your Own Neem Oil Insecticide with Wildcrafted Neem Oil.
Add ½ teaspoon of a mild liquid soap like Castile to 2 qts water and mix it up. Then add ½ ounce of Neem Oil slowly into the water while stirring it or slightly shake it up.
Spray the all of the leaves with your homemade insecticide on the top and bottom and saturate the soil with it, too. Make sure to shake it while spraying to keep it mixed well and repeat spraying them once a week or more if it rains. Solution will lose its potency after 8 hours.
It will not instantly kill the insects until they bite into the leaf but it will instantly repel them with its strong smell. Neem Oil pesticide has been known to kill and control aphids, moth larvae, spider mites, white flies, and Japanese beetles. It will not harm insects that do not chew the leaves like butterflies, ladybugs and bees.
Caution: Be sure to label carefully. Neem Oil is toxic and should never be taken internally.
Recipe from: http://www.ehow.com/how_5111583_make-neem-oil-pesticide.html