sees all my extracts din't post so here is the rest:

http://tcdc.undp.org/tcdcweb/experiences/vol4/Neem%20biopesticides.pdf.

Neem leaf extract
For 5 litres of water, 1 kg of green neem leaf is required. Since the
quantity of leaves required for the preparation of this extract is quite
high (nearly 80 kg are required for 1 hectare), this can be used for
nursery and kitchen gardens. The leaves are soaked overnight in water. The
next day, they are ground and the extract is filtered. The extract is
suited for use against leaf- eating caterpillars, grubs, locusts and
grasshoppers. To the extract, emulsifier is also added. Remarks: The
advantage of using neem leaf extract is that it is available throughout
the year. There is no need to boil the extract since boiling reduces the
azadirachtin content. Hence the cold extract is more effective. Some
farmers prefer to soak the leaves for about one week, but this creates a
foul smell.
General remarks about spraying
• Spraying should be undertaken in the morning or late in the
evening. Under hot conditions, the frequency of spraying should be
increased. In winter, spraying once in 10 days and every day in the rainy
season is recommended.
• Insects lay eggs on the underside of the leaves. Hence it is
important to spray under the leaves also.
• While using a power sprayer, the quantity of water used should be
halved.
• It is better to use low concentrations of extracts frequently.
• As a general guideline, it can be said that each acre of land to
be protected can be sprayed with 60 litres of ready-to-use solution (not
the concentrate). Of course, the volume may have to be varied depending on
the exact conditions prevailing, such as the intensity of the pest attack.


Biological effects of neem on insects
The action of neem products as pest control agents can be manifested at
different levels and in different ways. This is a very important point to
be noted since the farmer would be used to the “knock-out’’ effect of
chemical pesticides. Neem extracts do not exhibit this type of effect on
pests but affect them in several other ways.

Insect growth regulation
Regulation of the insects’ growth is a very interesting property of neem
products which is
unique in nature, since the products work on juvenile hormones. The insect
larva feeds and as it grows, it sheds its old skin. This particular
shedding of old skin is the phenomenon of ecdysis or moulting and is
governed by an enzyme, ecdysone. When the neem components, especially
azadirachtin, enter the body of the larva, the activity of ecdysone is
suppressed and the larva fails to moult, remains in the larval stage and
ultimately dies. If the concentration of azadirachtin is not high enough,
the larva will die only after it has entered the pupal stage. If the
concentration is lower still, the adult emerging from the pupa will be
100% malformed, and absolutely sterile.

Feeding deterrent
The most important property of neem is feeding deterrence. When an insect
larva sits on a leaf, it will want to feed on it. This particular trigger
of feeding is given through the maxillary glands. Peristalsis in the
alimentary canal is thus speeded up, and the larva feels hungry and starts
feeding on the surface of the leaf. If the leaf is treated with a neem
product, because of the presence of azadirachtin, salanin and melandriol,
there will be an anti-peristaltic wave in the alimentary canal which
produces something similar to a vomiting sensation in the insect. Because
of this sensation, the insect does not feed on the neem-treated surface.
Its ability to swallow is also blocked.

Oviposition deterrent
Another way in which neem controls pests is by preventing the females from
depositing eggs. This property is known as oviposition deterrence, and
comes in very handy when the seeds in storage are coated with neem kernel
powder and neem oil. The seeds or grains obtained from the market may al-
ready be infested with some insects. Even these grains could be treated
with neem seed kernel extract or neem oil. After this treatment, the
insects will not feed on them. Further damage to the grains will be halted
and the female will be unable to lay its eggs during the egg-laying period
of its life cycle. There are also other known modes of action:
• the formation of chitin or the hard part covering the insect
• mating as well as sexual communication are disrupted;
• larvae and adults of insects are repelled;
• adults are sterilised; and
• larvae and adults are poisoned.
•
The use of neem products does not give immediate results, unlike chemical
insecticides. Some patience is required after the application of neem
products.

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