DE users: how often do you reapply outside?

[DonyaQuick]

I have been using food grade DE for premesis parasite control in large outdoor spaces where things like permethrin and elector psp just don’t seem to work. I’m having difficulty finding the right criteria or timeline for reapplication outdoors though. I don’t want to waste it or make a dusty mess by doing it too often, but waiting too long invites the return of bugs. So, for those that use DE outdoors in some capacity, how do you know when to add more to an outdoor space for bug control? I often end up waiting a few months because I inevitably forget it doesn’t last forever and that’s apparently too long in the warmer parts of the year.

A request for the non-DE folks: please don’t just reply with the usual respiratory irritation cautions and recommending permethrin instead, which is certainly great in OTHER circumstances, just not this one. This is a pretty big outdoor, well ventilated space with a lot of perimeter I have to control and I have tried MANY things and found DE the only one that works for more than a few days to keep things like grain mites and NFM out of the area in question - and yes I have been tearing my hair out trying to control the vectors that spread those pests but it’s a complicated situation and the solution for that vector side of things may literally take a few years to do properly. I’m open to non-DE suggestions but only if they’re cheaper or longer lasting and not something I’ve already tried (permethrin, elector, first Saturday lime)

 

[DLA]

Rain makes DE pretty much ineffective. You're never going to be able to get rid of all the pests and many solutions harm the beneficial insects and bees too so treating the coop itself and the birds and controlling any pests they may have on them might be a better option than trying to keep a whole area pest free.

 

[Kiki]

DE can't work if it gets wet so reapply it ever time it does get wet if you want it to work.

 

[DonyaQuick]

DE can't work if it gets wet so reapply it ever time it does get wet if you want it to work.

This is an over-simplification; it is ineffective while wet and obviously if washed away it's not there anymore. And if ground up it's ineffective too. However, if it is in an area where it can dry out after becoming damp/wet and remains in place it retains its effectiveness although it will be more slowly broken down from other activity. That rate of break down in partially protected areas is what I don't have a good handle on.

My assertion about retention of effectiveness is based partly on experimentation I've done in areas that get damp but not washed/flooded where i've seen it remain and observed it continue to be effective until actually gone. This has bee the most obvious using it on pathways that were bieng used by mold/grain mites going from nearby trees into my enclosures - so far it has stopped the seasonal mold mite bomb I've had to deal with in one area but that's a much easier place for me to monitor. The other part is having worked briefly in a lab where samples of very small shells including diatoms were collected by careful washing and filtering - so long as there was not grinding action, the shells were preserved once dried (and the shape of the shell bits is what makes DE work).

So, let me refine the question of DE longevity and reapplication to areas that are not subjected to fully washing away except in freak storms and also not subjected to heavy grinding activity (neither foot path nor dust bath). But also not a fully enclosed interior space where the stuff is going to linger semi-indefinitely.

Rain makes DE pretty much ineffective. You're never going to be able to get rid of all the pests and many solutions harm the beneficial insects and bees too so treating the coop itself and the birds and controlling any pests they may have on them might be a better option than trying to keep a whole area pest free.

Treating birds and interior areas only resulted in quite a long, ineffective, sporadic saga for me. Normally I would type out the lengthy explanation in detail but it's rather a lot in this case considering the complex mess of factors, some of which aren't even on my property and therefore are outside my control. The short version is that treating birds and inside the enclosure does not work when you have other wild animal vectors dropping bugs nearby repeatedly. Obviously controlling the vector becomes a priority but it is also a difficult and a long process in my case. The fact is that DE has been the treatment solved my bug issues for the longest time per usage out of all the things I tried. But, in instances where I've left it too long until it really was gone from the environment (which can be hard to tell unless I'm down picking around on the ground all the time) then the issues have resurfaced. At the same time, I don't want to be powdering every day since it's expensive. So there has to be some intermediate. I was just hoping to find an easy answer for that like without continuing my current trial and error process.

 

[DonyaQuick]

So to follow up on this after a lot of experimentation, I believe the magic number for my environment is: about 3 weeks in moderately protected areas. Sooner if a deluge washes the area out of course. And sooner if an area is heavily disturbed or walked on a lot. Longer to a lot longer in very well-protected areas. Haven't needed to replace it yet where there is no ground disturbance from people/animals and zero water. Billowing snow can reach further and I'm sure will clear out those well protected areas eventually with melts, but over the winter I also won't have to worry about mites crawling into the enclosures from outside like I do in warmer weather.

Also worth noting that one area on a board where I had serious grain mite traffic (so bad it was like a nightly invasion of dust bunnies trying to funnel in through that one spot) they did significantly chip away at the DE volume I'd put in place to block them, and if I left it long enough, it's possible that new bugs might have been able to traverse the DE line safely via a wall of old bug bodies. I didn't let it reach that point.