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JimS. 02-06-2003 05:32 AM

Neem oil and ladybugs
 
Will Neem oil kill sprayed on roses kill ladybugs?

JimS.
Seattle



Radika Kesavan 02-06-2003 06:44 AM

Neem oil and ladybugs
 
JimS. wrote:
Will Neem oil kill sprayed on roses kill ladybugs?


No, Jim, it won't.

Here is the relevant excerpt from EXTOXNET on Azadirachtin, the active
ingredient in neem oil:

"* Effects on Other Animals (Nontarget species): Azadirachtin is
relatively harmless to spiders, butterflies, and insects such as bees
that pollinate crops and trees, ladybugs that consume aphids, and wasps
that act as parasites on various crop pests. This is because neem
products must be ingested to be effective. Thus, insects that feed on
plant tissue succumb, while those that feed on nectar or other insects
rarely contact significant concentrations of neem products. Another
study found that only after repeated spraying of highly concentrated
neem products onto plants in flower were worker bees at all affected.
Under these extreme conditions, the workers carried contaminated pollen
or nectar to the hives and fed it to the brood. Small hives then showed
insect-growth-regulating effects; however, medium-sized and large bee
populations were unaffected (234). A study of neem products and their
effect on mortality, growth and reproduction of earthworms in soils was
conducted. Positive effects on weight and survival were found in soil
treated with ground neem leaves and ground seed kernals under greenhouse
conditions. Reproduction was slightly favored over a period of 13 weeks
in a neem-enriched substrate in rearing cages. Various neem products
were incorporated in the upper 10-cm soil layer of tomato plots. None of
the materials had negative side effects on seven species of earthworms
(240). No significant effects on other wildlife were reported (238)."

In case you were curious, here is where you will find the rest of the
article:

http://ace.ace.orst.edu/info/extoxnet/pips/azadirac.htm

I have seen a few papers publishing original research on the effect of
neem oil on ladybug larvae, and as I recall it, on the specific ladybug
varieties they studied (there were about a half-a-dozen, IIRC), there
was little effect on the larvae's development into mature ladybugs.

--
Radika
California
USDA 9 / Sunset 15



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