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Fly Stoppers
SmartPak Equine (#27055)

Fly Stoppers™

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As riders and online shoppers, we know it can be tough to buy a new bridle or pair of boots without trying them on. That's why we moved the fitting room to your living room (or barn)! From breeches to blankets, if you or your horse can try it on, you can return it, free! Just request a return with a FREE SmartPak return label from your Order History within 60 days of the purchase date. And of course, please make sure the item is in like-new condition with original packaging (we said 'fitting room', not 'war room'!).

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PLUS! You'll save % on every shipment if you order this product on AutoShip
You'll love our AutoShip because it's:
  • Focused on healthy s, because consistency is key
  • Easy to snooze or cancel online, anytime
  • Totally flexible - edit your order as often as you'd like
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PLUS! You'll save % on every shipment if you order this product on AutoShip
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Zone Map
Begin with the zone for the state you are in. Dates shown on the map indicate suggested start and end dates for Fly Stoppers™ shipments. You may want to shift a zone if your elevation or microclimate is unusual, or if you fall on the border between two zones. You can start anytime during the fly season. Choose "Year Round" for climates that have flies all year, and start now.
Program Type Shipment/Application Frequency
Regular Programs: Ships every 4 weeks. For low to average fly levels, frequent manure management and few neighbors.
Premium Programs: Ships every 3 weeks. For high fly levels or weekly manure management or nearby livestock.
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Before purchasing this item, please note:

  1. This item can't be shipped to a PO Box.
  2. This product will be shipped directly from the manufacturer using a shipping company.
  3. The freight company will call you to schedule a delivery appointment.
  4. If SmartPak and the shipper are unable to contact you within 7 business days of the product shipping out, your order will be cancelled.
  5. You may be liable for any storage fees due to missed delivery appointments or requests for dates beyond the standard delivery window.
  6. When your shipment arrives, you will be responsible for inspecting the shipment to make sure it's complete and that no items are damaged.
  7. Before accepting the shipment and signing for it, you must record missing items and damaged items on the receipt, and take pictures of any damage.
  8. SmartPak and the manufacturer will not be able to assist you in filing a claim if you haven't noted any damage on the receipt. You will be responsible for filing any claims.

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Please call 1-800-461-8898 to order this product.
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SmartPerks Putting your horse's supplements on AutoShip helps you take great care of your horse, so we take great care of you with SmartPerks! When you order your horse's supplements on AutoShip, you're automatically* eligible for our FREE SmartPerks benefits, including:

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*At least one individual AutoShip supplement or horse's SmartPaks must be over $40. Some exclusions apply. Visit or call 1-800-461-8898 for details.


Why We Love This

Fly Stoppers™ are the smart way to make your farm a no-fly zone! These tiny, beneficial bugs stop adult pest flies from developing by feeding upon and breeding within the developing (pupal) stages of manure breeding flies.

Fly Stoppers™ work by seeking out their target host – the fly pupae – and depositing their eggs inside them. These eggs then hatch and begin to grow and feed on the developing fly, thus stopping the adult pest fly from hatching. Once mature, the Fly Stoppers emerge from the fly pupae to look for a mate and the female Fly Stoppers™ continue to lay eggs in fly pupaes.

While Fly Stoppers™ reproduce in approximately three weeks to replenish the beneficial insect population, pest flies do reproduce at a faster rate than Fly Stoppers. That’s why Fly Stoppers must be reintroduced to your property on a regular basis. We recommend releasing a shipment of Fly Stoppers™ every three to four weeks throughout fly season for maximum results. If you order them on AutoShip, you’ll save 5% on every shipment and you won’t have to remember to reorder every month!

Please note: Hatching can take up to 10 days, and Fly Stoppers like to be warm and cozy before they hatch. Wrapping them in a pillow case and storing on top of a fridge or hot water heater can help!
Favorite Features:
  • Beneficial insects stop pest flies from developing, helping to control the fly population at your farm
  • They're a chemical-free solution you can feel good about using
  • You'll prevent flies from developing before they can bother your horse
  • Spend just five minutes releasing them each month and enjoy a fly-free farm all summer
  • Put them on AutoShip ad you'll stop stressing about your fly control program and save 5% on every shipment
(Maintenance Dose = )
Ingredient Amount
Instructions for Use:
  • Fly Stoppers are shipped via US Mail as parasitized fly pupae in wood shavings.
  • When received, check for evidence of hatching.
  • Once a few have hatched, simply disperse small handfuls or scoops around your property into "hot spot" breeding areas, such near manure piles, under water troughs, below bedding, the corners of pens and paddocks, and feeding sites.
  • Cover with dirt to protect pupaes.
  • If you do not see movement within the bag, you can speed up the process by placing the bag in an old pillowcase and setting it on top of your hot water heater or refrigerator. Make sure you check them every day for fly parasite activity.
  • It may take up to 14 days for hatching to occur at various time during the fly season.
  • You can release the Fly Stoppers before they hatch; however, they must be covered with a thin layer of manure or ground cover to prevent birds and ants from consuming the unhatched fly parasites.
What Customers Say:
Fly Stoppers™ is rated 3.2 out of 5 by 32.
Rated 5 out of 5 by from Good bye flies! We use these at the barn and this year I decided to try them at my house around the dog kennel. Has helped a lot in reducing fly populations.
Date published: 2020-07-23
Rated 5 out of 5 by from Working I am glad I added flystoppers to my fly control this year! They are working
Date published: 2020-07-12
Rated 2 out of 5 by from Was happy, but the last two shipments were duds. I have been buying these since early spring to get ahead of the fly population. I've used Arbico organics for several years, was happy to see SmartPak had a version so I gave them a try. They seemed to be doing comparable job, but I decided to go up in size just for the added protection. I have used the premium shipping right from the start, having them delivered every 3 weeks. I have received two shipments now of the double sized order, and neither have hatched. I have been using fly predators for years, so it's not a user issue, it's a product issue. Needless to say, I'm disappointed, and will be canceling this autoship and requesting a refund.
Date published: 2020-07-05
Rated 1 out of 5 by from SmartPak needs to be more forthcoming I have used a competitor's brand of wasps for a few years before SmartPak came out with their version. I switched to SmartPak, because I love the company and their products. After some time using their version, Fly Stoppers, my fly problem was never really improved. I tried doubling the amount, shipping more frequently, and then I came across a Podcast that named specific species of wasps. After digging into SmartPaks description of their Fly Stoppers, and chatting with a SP staff, they are not willing to disclose the type of wasp used in their "proprietary blend" of Fly Stoppers. This is a big red flag for me!! I am sad to say, this is the first time I have been disappointed in SmartPak. I cancelled my Fly Stoppers, and will be ordering from the competition from here on out.
Date published: 2020-06-18
Rated 4 out of 5 by from very pleased used them for the first time last year. I house three horses on my property. Two belong to me and one to a friend. I never told her I was using them because I wanted to see if she noticed a difference. we went to the vet and he brought them up and I responded " yes I am trying them this year" My friend had know clue I was using fly stoppers or even what they were but she did comment that she had noticed less flies around my property. We are definitely going to try them again this year. Now if anyone can come up with something to control the Horseflies that would be a God send
Date published: 2020-03-07
Rated 5 out of 5 by from These little bugs really make a difference! The flies were starting off horrendous this spring with all the rain we had. The horses were miserable and I was doing all I could to reduce flies and they were getting worse by day. I started the fly stoppers and within a week the flies were obviously reduced and the horses were barely swishing their tails! I went to auto delivery every three weeks and the results were amazing. I’ve done fly predators in the past from different distributors but never saw such an obvious difference as I did this season. will definitely do again next season!
Date published: 2019-09-10
Rated 1 out of 5 by from Terrible This is the 2nd year I’ve tried these and there’s no difference in the terrible fly population. I’ve done everything recommended including starting at the beginning of fly season, over ordering the fly stoppers, bait and traps. And as far as 100% happiness guaranteed, all I got was a oh, sorry they didn’t work for you. Total waste of money.
Date published: 2019-09-04
Rated 5 out of 5 by from Work well if used correctly Any negative review on these I firmly believe is because they are being used incorrectly. Please read the directions: buy for the appropriate amount of horses first of all. Second: release when they are just starting to hatch. Third: release in the areas that have the most manure. Fourth: rotate release sites. Finally: I do recommend a "double dose" at first. For example: my farm has 12 horses and we are next to another small farm with horses and livestock. I use the 10-15 horse (1.5 bags) order every 3 weeks (as recommended). Initially, I released the 1.5 bags with another 1 bag a week later as a "boost". Since then, continuing every three weeks. Our flies have been cut down to 10% of what they were before. I wish I had taken pictures. Moral of the story: do not try to cut corners. The recommendations are there for a reason. Follow the instructions and these work very very well.
Date published: 2019-09-01
Rated 5 out of 5 by from funny story It was a great product but I would say warning not to let the package sit in the garage for several weeks under extreme heat would have worked wonders. They ended up hatching before I wanted them to but I don't have any flies in my garage or house now. i'll be more careful next time but great product.
Date published: 2019-08-19
Rated 1 out of 5 by from I think my flies have gotten worse These did not work at all, I actually think I have more flies since I spread them around.
Date published: 2019-07-18
Rated 5 out of 5 by from this is the 3rd year using fly stoppers our 4 horses paddocks are very close to the manure pile - the fly population has been greatly reduced! All of our shipments have hatched & we have followed the instructions We are very happy with the results! We will continue next year!
Date published: 2019-06-28
Rated 3 out of 5 by from one time disappointment I have been using Fly Stoppers and have been pleased until last shipment. I had always worried about extreme heat or cold and never had a problem until last shipments. I usually leave bag handy until I see activity and then release. This time nothing ever happened. I did finally leave in small space so I could continue to monitor . Have you had this problem?? I'm not sure I want to continue ordering if product is DOA.
Date published: 2019-06-26
Rated 1 out of 5 by from STILL have not hatched I have a bag of fly stoppers from last year. They never hatched last year. They have been sitting on the top of my fridge for the last year. I just took a look at them for this late June.... they STILL have not hatched. I recommend going with Fly Predators instead!
Date published: 2019-06-23
Rated 5 out of 5 by from Excellent idea I've used this for several years in various states. I have never seen a better product for preventing flies. And NO chemicals involved!
Date published: 2019-06-17
Rated 5 out of 5 by from I’m impressed!! We’re on our second month of using fly stoppers and there’s definitely a difference in the amount of flies in our barn. If you see the fly stoppers hatch and get them in the hot spots at dusk you will too. I highly recommend these.
Date published: 2019-06-15
Rated 5 out of 5 by from Fly Stoppers work! Sprinkled these around both the horse barn and alpaca barn. They work!
Date published: 2019-06-12
Rated 1 out of 5 by from More flies than before We’ve used these for a few months now and unfortunately have more flies now than before.. not sure what to do now :(
Date published: 2019-06-10
Rated 1 out of 5 by from Have seen no change with flys I bought this product and have seen no change, flys are terrible.
Date published: 2019-05-27
Rated 4 out of 5 by from So far so good! So far so good. We just moved to MO and none of our neighbors have livestock. I decided to try to get a jump on fly season this year and choose to give fly predators a whirl. Been using them for two months and so far the flies haven't been bad. All the other bugs are out of control, and the mud, but at least the flies aren't bothering the horses much. We've got 3 full sized horses and 3 minis. I'll keeping using them and hopefully the flies will continue to stay at this minimal level.
Date published: 2019-05-06
Rated 1 out of 5 by from Not effective Had used Spalding Fly Predators for years with great success.Last year tried the Smartpak Fly Stoppers instead and the flies were out of control. Unfortunately the flies being out of control also lead to the spider population count rising to incredible new heights as well. Which lead to me spending a lot of extra time knocking down cobwebs. Time I much rather would have spent with the horses.
Date published: 2019-04-17
Rated 5 out of 5 by from Love Fly Predators! We have used fly predators for the past six years. Didn't start until August of the first year (not ideal!) but we did see some improvement so we've kept it up since then. Each year is better and better and we see a decrease in stable flies year after year. We have four equines (2 horses, 1 pony, 1 mini horse). In the past, I've ordered "up" and done the 6-10 horse bag every 4 weeks. This year I'm trying the 1-5 horse, 1/2 bag every 3 weeks and we'll see how that goes. If we had 4 or 5 full sized horses, I'd personally be inclined to order up just in case.
Date published: 2019-04-08
Rated 1 out of 5 by from Fly stoppers I hate leaving terrible reviews, but I have been using the name brand of these for years with little amounts of flies. When these became fly stoppers, within a couple months my barn was overloaded with flies. Not sure what changed, but disappointing to say the least when you spend $20/month spring to fall for something that used to work.
Date published: 2019-03-11
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Q & A
How to use Fly Stoppers™
SmartPaker Emily shows you how easy Fly Stoppers are to spread and gives you some tips and tricks so you can get the most out of these bugs!

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