It's also what the garden people told me, and the organic garden problem-solver book I use for reference states to use neem sparingly. Plus, when I used neem in my own garden, I found dead bees the next day, and that was the only product that I used. It wasn't an old solution, but the bottle of Neem was about a year old. Maybe that was it.
I am concerned with the quality of information on neem that some garden centers are giving out and that is in some well meaning publications
There are many grades of neem oil, and many times they are not pure - I have accidentally purchased some counterfeit oil myself.
A neem oil that is not labeled for use as a pesticide might cause all sorts of problems. There are not very many pesticide approved neem oils in the world, and none on the shelves in our area - within the next 8 weeks, we will be placing our EPA approved neem oil onto shelves. The toxicology data on our specific, very quality controlled neem oil is available at http://www.epa.gov/oppbppd1/biopesticides/ingredients/tech_docs/brad_025006.pdf
Direct quotes from the EPA include "There are no concerns for any non-target organisms when 100% Cold Pressed Neem oil is applied in accordance with EPA-approved label use directions. No toxic endpoints have been identified for non-target birds, non-target plants, and non-target soil organism such as earthworms."
"Honey bees and other pollinators that feed on nectar, and predators of insect pests are unlikely to consume sufficient quantities of Cold Pressed Neem Oil to cause adverse effects. Bees have been reported
to avoid foods that contain >100 ppm Cold Pressed Neem Oil."