After having some issues with cucumber beetles eating my garden up I discovered Diatomaceous Earth in this forum. From the looks of it this could have been exactly what I was looking for since I would prefer not to use pesticides. I have some questions related to its proper use and effects.

For reference I bought this Diatomaceous Earth and this duster.

What is the best way to apply? Wet the leaves and then dust on to the leaves?

What about the leaves further down in the plant? Is it more effective if I dust the inner leaves first?

How often should I re-apply?

Should I put it on the soil?

What is the effect on bees? I've read both that it will kill them and not harm them but I don't know what to believe on the internet.

Will it prevent the bees from pollinating the flowers in the garden?

I welcome your expertise on the proper use of DE!

I'm going to guess, but don't wet the leaves first. DE will have its  own tendency to cling to your plants. If you allow it to get wet it is likely to clump, and become less effective.

DE kills insects by scratching the chitin (the shell material) which has a waxy surface; the bug then dehydrates. It'll also get in their joints and wreak havoc there.

Diatomaces Earth is the skeleton left behind by microscopic oceanic animals. Ithas sharp corners and spikes. Being made of silicone, it's very durable and won't get dull.

Also I'm curious if there are any human health effects I should be concerned with. Several places advise that it is a carcinogen.

You need fresh water sourced DE, then make sure it is food grade. It is actually used for grain storage as a pesticide and helps grain flow and absorbs moisture. I'm a health but, and ingest DE all the time from grinding our wheat that is stored dusted with DE. Do not inhale, dries out your skin like now.

I've tested DE on a house spider I caught. Doesn't kill spiders within 48 hours for sure.

There's more than one type of DE, even one which can be added with stored grains.  The DE used for some swimming pool filters must not be inhaled, it cuts up the lungs.

It can be used as a pest control in the yard
You can get a large bag for cheaper at feed stores.

So I need to re-dust after rain?

Any work on the impact on bees? or risks that my vegetable flowers wont get pollinated?

After rain the DE will dry back out and keep working, but it will wash in the the crevices and cracks of the soil and out of reach of the crawlies. Re-apply as needed.

 

Bees: Yes, maybe and no. I have not noticed any decrease in bee activity (except after they spray the fields around me with poison, when bee population in my garden drops by at least 75%) due to DE. Since bees are very good about only landing on flowers, unless you dusted the flowers the bees should not contact the DE. I also know DE doesn't kill all bugs (like spiders), so perhaps the DE doesn't bother them too much.

Introduce lady bugs and praying mantis to your garden. They are inexpensive and effective. -W

I was thinking about this, the mantis in particular. I did not for two reasons. First I've already used some pesticide on the garden which didn't kill the beetles but might kill the mantis and secondly the garden is very small and I wasn't sure the mantis would stay there.

Run a search on diatomaceous earth just to do so and read up on it.



Then find a tractor supply or something similar and I would buy the mid size bag, about the size of a big bag of ice for a cooler.  Not sure on weight, does not weigh much.



I recomend not breathing any of the dust from any of the diatomaceous earth.  Someone said just not the pool stuff, the tractor supply stuff is a fine powder and I just figure it won't do my lungs any good to sit around and inhale it.



In running your search you should see that some types are food grade, my tractor supply sells such as an animal supplement.  It is in the horse and cow and goat foody section.  They have 2 or 3 sizes of bags and sometimes they are scattered around the store with some here and there to snag the attention of folks who might not be looking at the goat foody section.



I like something like a canning jar or coffee can with holes punched in the lid and use it as a dusting setup.  Watch the wind and what not.  As mentioned rain can rinse things off.  The dust will stick to some stuff and settle down, I don't have a garden per say, but I like to dust things and also make a border of the stuff so anything crawling in goes through it but the dusting of the leaves handles airborne attacks.



Some folks take it themselves and many give it to their dogs and stuff as a sort of wormer.  It is said to cut up worms in the intestines and be a natural way of worming yourself or your animals.  In playing with search you have to decide for yourself what you think.



I know some folks dust food with it as well for longterm storage and I would not worry about ingesting some as long as what I have is the food grade stuff.



One thing I messed with was using it in a house with a bit of carpet and then wondering how well the filter for the vacumn would work in picking the stuff up and not making it airborne to where I would inhale it.  One of those things you can decide for yourself.  I don't mind slowly sweeping it for getting most of it up and then a damp paper towel will get up any remaining dust on wood floors or linoleum.  Carpet made my brain want to flip coins.



It tends to be popular with the folks that dislike chemicals and what not.  I use it.  It has its uses.  So does outright poison of some such, like too much water.  Drowning bugs can work as well.

Go with lady bugs then, they are a type of beetle.

silica not silicone.

I put it on last night.  I found that depending on the orientation of the duster puffer I either blew out too fine a dusting (barely visible) or too heavy a coating totally covering the leaves.  So anyone know the proper way to use that puffer in my op?  I also noticed I was standing in a small thin cloud of de. Worth wearing a respirator or eye protection?

Side note : how thick does it need to be to be effective?

Keep in mind this stuff is not a poison.



For something with a shell you are using tiny sharp objects to cut up that shell and bleed it out.  Most sites use the word dehydrate.



Your duster probably will be a toy to play with for a bit til you are consistant with how you use it.



Even with my jars with holes in the lid I get various amounts out of it.  If it is upright and I turn it upside down I get x.  If I shake it I might get more or less depending on how hard I shake it.



Learn to be consistant and you will figure out how to do it in a timely fashion.



As for how much to put down, I put down a thick line on the perimeter since everything has to crawl through it and it tends to hold up depending on how much the rain hits it directly.



For what goes on leaves, I would barely want a dusting on it, leaves have a job to do and covering them up will make that job harder.



I have used the little canisters sevin dust comes in as well as the bottles that foot or body powder comes in.



Overall I found out that nothing I deal with is as fine as DE and it comes down to me deciding how to do it.



I am somewhat known on days with zero wind to just let a huge cloud of the stuff settle over something with leaves as I leave the area.



I try hard not to inhale it or get it in my eyes.

Well its been a few days and I cant be sure but I think I've seen less although not zero beetle activity. Does it really work this fast? The few sites I've read say it can take weeks. We just got a rain last night so I will re-apply tonight.

Oddly enough that shit is food grade...

In before the nut on here that eats it regularly, just in case he has parasites...

The package the DE came in actually has a recipe for mixing 1 tbsp into water and drinking it daily. I think the risk is mainly from breathing the dust in. No idea if there is any benefit to eating it and I don't plan on finding out. Mine is purely here to kill these damn beetles!

Just wanted to add that the DE works great in the house for getting rid of ants. Just sprinkle some on their trail and they're gone within a day or two!

I think it works on bugs that are low to the ground and bugs that like to groom them self. Or am I thinking of boric acid?
( boric acid works great for a dog with an eye infection)