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Farnam Companies, Inc. — Item #12587
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Breaks the fly life cycle

  • Prevents the formation of fly larvae's exoskeletons when they molt (resulting in their death)
  • Contains no organophosphates & can be used as part of an integrated pest management program
SimpliFly with LarvaStop is a highly palatable additive to prevent the development of stable flies and house flies in the manure of treated horses. LarvaStop breaks the fly life cycle by preventing the formation of fly larvae's exoskeletons when they molt (resulting in their death).

SimpliFly contains no organophosphates and can be used as part of an integrated pest management program. SimpliFly with LarvaStop is a reduced-risk pesticide.

View our Insect Control Supplement Comparison Chart


Active Ingredients:
  • Diflubenzuron (Dimilin)
Inactive Ingredients:: Wheat Middlings, Dehydrated Alfalfa Meal; Calcium Carbonate; Sodium Chloride; Calcium Propionate (preservative)


Instructions for Use:
Feed the recommended dosage of SimpliFly to each horse separately to make certain he receives his full portion. This product should be fed top dressed on grain or mixed with the horse's total ration to provide 6.8mg of diflubenzuron per 100lbs of body weight. For an occasional finicky eater who does not accept new feeds readily, mix this product with sweet feed or grain ration.

Daily Dosage
300 - 500lbs : feed 2/5 oz. per horse per day
500 - 700lbs : feed 3/5 oz per horse per day
700 - 900lbs : feed 4/5 oz per horse per day
900 - 1100lbs : feed 1 oz per horse per day
1100 - 1300lb horse : feed 1 1/5oz per horse per day.
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    out of 5
    89% of customers would recommend this product to a friend!
    Tell us what you think!

    The reviews provided on this website represent the experience of the individual posting the review. We do not adopt, edit, or endorse any of the submissions posted within the reviews section. Rather, the reviews are part of an online community of animal owners that desire to share their particular experience with other individuals. These reviews are not a substitute for discussing the health of your animal with a veterinarian.

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    SimpliFly is rated 4.5 out of 5 by 195.
    Rated 5 out of 5 by from definitely seems to help We decided to give this a try this year and it has definitely helped. The regular flies have been drastically reduced and the manure piles do not have any flies swarming around them. We really have only had to deal with mosquitoes and the huge horse flies, but I even think it's somehow helped a little with the horse flies... will definitely keep using this. Horses eat it no problem.
    Date published: 2017-08-16
    Rated 5 out of 5 by from Actually works! Been on this for three months. It has lowered the fly population at our barn. Too bad we can't use it with our chickens. We would have hardly any flies!
    Date published: 2017-08-14
    Rated 5 out of 5 by from Bye bye horse flies The horseflies used to swarm our truck the minute we drove under the pine trees that line our driveway, and that was before we even had any livestock on the property. So naturally, when we decided to turn it into a horse farm last fall, I was very concerned for the welfare of our horses. Early in the spring I put all the horses on a daily dose of Simplifly in the hopes it would keep the horsefly population from ballooning into an apocalyptic frenzy of blood suckers. Well I'm thrilled to say that we have no horseflies this year, not one! I am amazed at how well this product has worked. Even our neighbors have told us that the horseflies seem to have just simply disappeared after several decades of their summer bombardment. This product REALLY works
    Date published: 2017-07-25
    Rated 5 out of 5 by from Really helps!! I ran out of it and the flies went crazy! It made me realize what a great job Simplifly is doing to help control the population!
    Date published: 2017-07-14
    Rated 4 out of 5 by from Really cuts down on the fly population! This product really helps to cut down on the fly population for my 2 miniature horses, and 1 horse on my 1 acre property. I recommend it during fly season.
    Date published: 2017-07-10
    Rated 3 out of 5 by from Very palatable I've been using this since the start of the summer on a property that never previously housed horses. Unfortunately, we still have flies, both stable and house flies, and gnats etc, despite using Simplify. However, I am continuing to use it on the basis that the problem could be worse if I stopped.
    Date published: 2017-07-07
    Rated 3 out of 5 by from Not completely sold on it Started my mare on it in early spring before fly's really came out. It has defiantly helped keep fly's out of her stall but thats about it. Most of the horses at my barn get fed a feed through fly pellet of some sort during spring and summer so fly's at barn are not horrible. However I feel at least for my horse I got better results and had more benefits from feeding the garlic flakes. So once this bucket is done there is a good chance that I would switch back to garlic flakes. I that being said my horse has no problem eating it at all.
    Date published: 2017-07-07
    Rated 5 out of 5 by from Greatly reduces the fly population I used this in combination with garlic flakes and I notice a huge difference in the flies. I start before the spring heat hits, and flies never have a chance to get started. There are no flies buzzing around the manure pile when my mare is on this.
    Date published: 2017-06-30
    Rated 1 out of 5 by from More Flies Than EVER! Used this product in the past and it was great. This year I am on my second 20lb bucket and I have more flies than ever. I use fly bags, strips, manure spreader and the feed thru. Billions of live larvae in the manure when they should be none. I am so disappointed. My horses are miserable and going in my barn is horrible.
    Date published: 2017-06-19
    Rated 1 out of 5 by from I have used this product for years and loved it, this year however it seems to have little to no affect after three buckets. I called the manufacturer and their reply is to produce the sale slips for the product, so since I don't save every sale slip I have, I guess the hunt is on for "proof" of purchase. I wonder if this product is losing effectiveness like the flea control did. Either way my barn is over-run, is anyone else having this problem?
    Date published: 2017-06-17
    Rated 4 out of 5 by from So far so good... Champ has only been on the simplifly a little over a month. Although I still see a few Flys on him every now and then, they are very minimal. He takes the simplifly along with the double strength farriers formula and the smart dark and handsome and I have been very pleased with the results of those two!!!
    Date published: 2017-05-31
    Rated 4 out of 5 by from Works good. I have been using this product for several years and it works good for average Flys. However, it would be nice if it worked as well on gnats, yellow flys, and horse flys.
    Date published: 2017-05-26
    Rated 4 out of 5 by from Less flies It's about about 2 months and so far so good. I notice less flies bothering him and I'm not using massive amounts of fly spray like last year when he wasn't on it. It's pellet form too which my horse prefers.
    Date published: 2017-05-10
    Rated 5 out of 5 by from Definitely works! I own a horse retirement facility with irrigated pastures, and have been using Simplifly for over 6 years now. The key is to start feeding it at the first sign of flies, to stop the fly lifecycle before it gets to a full blown roar. We live in California and I started using Simplifly the last week in April for 2017. This works better than any fly bait or spray system you could buy!
    Date published: 2017-05-02
    Rated 1 out of 5 by from No change in fly population! I have consistently used the whole tub and have seen no difference in the files. I worm on schedule, rotate pasture, spread manue, and are consistent with my use of the product, but absolutely no difference. I am willing to purchase another tub, but it will be my last unless I see some results.
    Date published: 2017-05-01
    Rated 5 out of 5 by from Great product! I've been feeding Simplifly to all my horses for the last four years. Super easy to feed, we only give it during spring and summer. Since feeding Simplifly, our fly population has greatly dwindled. Makes a huge difference!
    Date published: 2017-04-21
    Rated 5 out of 5 by from Great product I have been using this product since December 2016. I have ZERO flies in my barn!!! I highly recommend SimpliFly, as it is easy to use and economical.
    Date published: 2017-03-27
    Rated 4 out of 5 by from Works pretty well I've been using Simplifly for several years now and I always wonder if it's working. Then I run out and find out just how well it IS working.
    Date published: 2017-01-07
    Rated 5 out of 5 by from definitely works Is palatable & easy to feed. Works better than anything we've tried including fly predators!
    Date published: 2016-10-25
    Rated 5 out of 5 by from No flies! I have been feeding this to all three of my horses since I moved them home and I have absolutely zero flies! It absolutely works! I wasn't expecting it to work as well as it has. I will definitely be continuing to feed this.
    Date published: 2016-10-16
    Rated 5 out of 5 by from Love it it really helps keep the biting insects if We moved to a new barn and couldn't figure out why our horse Wicked was breaking out and rubbing her tail then I found out she was allergic. And our new barn didn't supply it so we put her the simplify and she's all better!!
    Date published: 2016-10-12
    Rated 3 out of 5 by from Easy to feed... didn't seem to impact flys This product was easy to feed and a good value. However, we did not see a significant impact on the number off flys (granted, it was an AWFUL fly year for us and even the fly predators didn't seem to help much). I'd give it another shot.
    Date published: 2016-09-27
    Rated 5 out of 5 by from Another way to fight flies In Tucson we have a very long fly season with some especially harmful species. I try and attack the issue from multiple directions, masks, fans, clean up, auto fly systems. This adds another avenue to break the cycle.
    Date published: 2016-09-05
    Rated 4 out of 5 by from Great product! I've tried other feed through larvicides, but was concerned about the strong chemical smell. This works well, when combined with other fly management efforts.
    Date published: 2016-08-12
    Rated 5 out of 5 by from Works for us! I started using this product at the end of June. The flies were terrible here in North Texas. I have have seen a drastic reduction of flies around the barn since using SimpliFly. I'm so glad I gave it a try. The horses don't seem to mind the taste, even my pickiest eater cleans her bucket.
    Date published: 2016-08-03
    Rated 3 out of 5 by from Not sure I bought this for my fly battle, my horses ate the pellets with no problem but I don't think it's the right product for me. Too many animals on my farm and too many farms in my neighborhood, I wonder about the cost versus effectiveness.
    Date published: 2016-08-01
    Rated 5 out of 5 by from I can't believe the difference! I tried fly predators last year and still had a lot of flies. This year I tried Simplifly instead. I started in April, before the flies really started to come out....WOW!!!!! I honestly cannot believe the difference!!! Other horse owners are complaining about stable flies but I have none! My farrier commented on the lack of flies as well... I will continue to use this next year.
    Date published: 2016-07-28
    Rated 4 out of 5 by from Smells rough, but works! I bought this a little over a month ago and am really happy with how it's been keeping the flies away, they stay off the horses and off the manure pile - works great
    Date published: 2016-07-13
    Rated 3 out of 5 by from fly product Can't give a good review since I've only been using this for 2 months and I believe it takes longer than that for the full effect. I have not seen a reduction of flies so Im not real happy with the product.
    Date published: 2016-06-23
    Rated 5 out of 5 by from Great results I have two quarter horses and since I started this product in the spring I am very pleased with the results! It has cut the fly population down by 80%. My horses are much happier too!
    Date published: 2016-06-23
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