Simplifly: half life of diflubenzuron (active) is 2 days in horse; 6-8 weeks in manure pile

[CHollyB]

Riders with a science background, how do I think through simplify when not everyone will use it every day, and some horses will not be dosed at all. BUT most will be dosed at least 3 X week.

The manufacturer’s information states that every horse must receive it every day. That would maximize sales for sure. I’ve also read that diflubenzuron is active in manure piles up to 6-8 weeks. The compound interrupts the chitin cycle of the larvae. So, realistically, considering that not every horse owner is around every day to dose their horses, and some horse owners won’t dose their horses, what percent of horses need to be on Simplifly, and how many doses can they miss? Even a guestimate is better than I can figure out.

For example, you have 100 horses, 60 of which are dosed daily and 20 are dosed three times a week, and 20 refuse. Is that still protective? The manufacturer’s advertising would say no. Hard to believe based on the active ingredient half half-life in horses and piles.

[Simkie]

Instead of doing this, just spray your manure pile with an IGR. Hell of a lot cheaper.

[CHollyB]

What spray do you recommend?

I think diflubenzuron is an IGR chitin wrecker, tho. As in, it interrupts the chitin stage of the larvae, which works in the horse but also in the manure after. Sadly, it’s not ‘my’ manure pile, and thus far, horse owners are game for insect management, but the manure goes to local growers and can’t have too much non-manure in it. So, treat the horses and indirectly treat the manure.

[Simkie]

You can use diflubenzuron.

I use this because it breaks down more slowly.

NyGuard IGR

A quarter ounce of diflubenzuron fed once daily is making it into one, maybe two, piles of manure per horse per day. Feeding it sporadically, and not feeding it to every horse on the property, means that SO MUCH of the manure produced is untreated. It’s a gigantic waste of money.

So treat the manure instead. I’m not sure what you’re envisioning, but spraying the manure pile with an IGR isn’t adding “non manure.” It’s the same chemical, or type of chemical, just skipping the horse. HOW you’re applying diflubenzuron (or whatever IGR you choose) is immaterial.

But applying it directly to the manure is not only a hell of a lot more effective than treating 60% of your horse population, it’s astronomically cheaper.

[CHollyB]

That’s a great Idea, thank you!

By non-manure, I mean that if farmers are going to use the manure, it can’t have a detrimental effect on the growing process. I looked up whether beneficial insects, such as bees and butterflies, and other pollinators are affected by the activity of diflubenzuron in manure. Seems like it can be active up to 6 weeks. The paper I read reported that bees do OK, caterpillars- nope, and maybe worrisome effects for birds.

Most manure contaminants deteriorate from composting. Like ivermectin, antibiotics, etc. So farmers are OK with it. They’re also OK with diatomaceous earth, which is also a chitin destroyer, so I’ll have to find out about direct application of diflubenzuron to manure, bypassing the horse, which is by far the best idea.

[Simkie]

@CHollyB

Most manure contaminants deteriorate from composting.

And so do IGRs. In days to weeks they’re toast.

I’m really not sure why you think treating the manure via the horse is any different than treating the manure directly. The horse doesn’t change the IGR. If anything, treating the manure directly will allow you to use significantly less pesticide.

[JB]

@CHollyB

if farmers are going to use the manure, it can’t have a detrimental effect on the growing process

plants don’t have chitin Or any insect growth hormone (which is what some other IGRs interfere with)

IGRs don’t even impact fly predators.

As for any beneficial insect it might impact, which ones actively lay eggs in manure that’s been spread on a field?

[CHollyB]

@Simkie @JB
Your points are extremely helpful, thank you. It is not my ranch, and I’m working on the diflubenzuron pitch to management. Treating the manure pile is clearly the best option. Now I’m trying to anticipate the best response to agricultural growers when they ask the “what’s in the manure” question. Again, thank you for the detailed responses

[SusanO]

So is this OK to use in a pasture? The primary spot is next to the gate which has turned into a pig slop mixture of poop and mud after all the rain here and a pony running the fence line to come in. I know it is a perfect fly breeding ground and the horse will not graze there but it might wash into the grass.

And in that vein - can I sprinkle it on manure piles in the pasure? I can’t tell much from reading the literature.