nope, and I'm not buyin the bit about whiteflies, either.

I use worm castings all the time and there's no insecticidal effect at all.

Remember what the garden center is selling...........

Its used as a fertilizer and as a soil conditioner.

this isnt to say that its not good stuff - its really good stuff for sure!

but generally we use worm castings to amend soil, or to set off a biodynamic reaction when brewing a compost tea.

your garden center friend might have been thinking of diatomaceous earth

Do some research on Red Wigglers and how to set up a bin, then get some worms and build a bin. You'll always have some and wont have to pay for it.

There is a lot of anecdotal evidence that plants grown with vermicompost (or in the presence of large amounts of worm castings) are not as attractive to sap-sucking insects like whitefly. (It's not insecticidal but just a matter of the plants being less attractive than other plants due to some characteristic the castings give the plant.) Unfortunately there isn't very much scientific evidence to back that up, but maybe in the future; the science of vermicompost is in relative infancy. Consistency is the problem. It seems likely that it's happened in a few cases but figuring out why and how, and then making sure your particular batch of castings/compost will do the same thing is difficult and so any attempt is a crap shoot.

If you are willing to believe it, then aphids would also be kept at bay since they are sap-sucking as well.

The good news is that like any compost worm compost/castings are good for your plants whether they actively suppress diseases and pests or just enrich the plant, so I say it's worth a try. I will second the suggestion to set up your own bin and make your own. It's pretty easy. There's a great vermicomposting forum here on gardenweb and several scattered throughout the internet that will be happy to give you any info you'd like.

For now though, buying some castings and doing an informal experiment might be a fun and educational project, as long as the castings aren't too overpriced...

Here is a link that might be useful: Vermicomposting Forum

Ok, Then. So the worm castings are a good thing. Now my next question is how do I apply the wormcasting ? can I just spread it on top of the soil or do I mix it into the soil?

There's a Vermicomposting forum on Gardenweb (vermi=worms). More information than you can possibly use on worm poop.

As for how to apply, same as you would apply compost. You can turn it, scratch it in, or spread it on the surface. Most folks like to at least scratch it in (spread on the surface and mix up the top couple of inches of soil with a rake or hoe). If you turn or till other organic matter into your soil, add the castings at the same time.

Hmmm..........that explains alot. At out community garden we have a master gardener that always has plants that seem to never have pest issues. We're organic and don't really use pesticides to promote good bugs so I wondered how she did it. This past fall I happened to be there when she planted her fall veggies. At the bottom of each hole, she put a handful of worm castings. I didn't think much of it until now. I think I'll do alittle experiment this spring.

I use worm castings often,great for conditioning soil. I have not had much luck with it detering white fly's. I was told that once as well, yet never noticed a detterent. So now I just use a diluted mixture of kneem oil, works really well.