Yellow Dung Flies


Scathophaga stercoraria on Pig Dung

From Wikipedia:

Scathophaga stercoraria, commonly known as the yellow dung fly or the golden dung fly, is one of the most familiar and abundant flies in many parts of the northern hemisphere. As its common name suggests, it is often found on the feces of large mammals, such as horses, cows, sheep, deer, and wild boar, where it goes to breed. … Scathophaga are integral in the animal kingdom due to their role in the natural erosion of dung in fields.”

A researcher I have been corresponding with about the S. stercoraria we were seeing said that these flies normally appear on only cattle dung and are hard to grow even on horse dung. He was quite surprise we had them on our pig dung as they don’t live on domestic pig dung. I think I know why.

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I minimize the use of Fenbendazole, Ivermec and other commercial dewormers in a large part because my understanding is those classes of chemicals kill off things like dung beetles and other helpful insects. Primarily we control parasites via managed rotational grazing and feeding whey & garlic as well as the organic pest control done by our large flock of laying hens. Perhaps that has made a difference.

I suspect that we’re seeing S. stercoraria on our pig dung because our pigs’s primary dietary component is pasture in the warm seasons and hay in the winter. Coupled with the right dung composition and the lack of chemical dewormers this may be making our pig’s dung closer to that of cattle and the dung of wild animals.

These flies are an important part of the natural life cycle, breaking down the dung so that it can be used by the plants and soil fauna. This is one more good reason for natural and organic farming. Consider the Yellow Dung Flies as canaries in the mine.

On a related note, we have a healthy population of bees, both domestic and wild, in our valley.

Related: Worms Au Natural

Outdoors: 67°F/52°F Sunny, 0.25″ Rain
Tiny Cottage: 68°F/66°F

Daily Spark: Every day, thousands of innocent plants are killed and maimed by vegetarians and vegans. Help end the violence: Eat bacon! -Anon

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About Walter Jeffries

Tinker, Tailor…

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15 Responses to Yellow Dung Flies

  1. eggyknap says:

    I was wondering what those were, when I saw them on the dung from our first cow, who has lived at our place for nearly a month now. I thought they were oddly-behaved bees, until I actually looked at them.

  2. Kristin says:

    Thanks for this info, Walter! We purchased new property last year and rotationally grazed ever since. I did not see these yellow flies last year. But I did see lots of dung beetles. This year, however, the second year of rotating, I’m seeing them in the cow pies! I thought they might be another annoying pest!!

  3. I like the daily spark. But it is circular reasoning of course because bacon is coming from life that eats/kills innocent plants, and that makes it a joke. I like such jokes. What about the following fact regarding how plants grow: As I understand it, there is life in the soil, little tiny beings moving about (but you would need a scanning electron microscope to see these creatures) and they live of organic materials in the soil, but some of these beings eat those beings which are eaten but in turn are eaten by other beings until finally the original organic materials in the soil is transformed into a state where plants can access them and thus…plants depend on the slaughtering of all these tiny soil beings. It’s murder down there, and the plants like it that way!

  4. phil says:

    hey walter, another quick question for you. my sows are pregnant, and i dont at the moment have quality pasture and space for them to nest on. so i have built stalls, 8 by ten inside and 7 by ten outside for each stall. another farmer i know insists that i build rails on the inside of each room that the pigs sleep in and have their piglets in. he says build them 8 inches out from the walls and 8 inches high so when the mother lays down she cant lay down against the wall and the piglets have somewhere to run to when the mom lays. my sows are good mothers. they each had 13 piglets last year and i think they each sat on 2 babies, but im not sure. i just know they each had 2 die from their litter. but they are also a good 150 pounds heavier then last year. so i guess my question is, are these rails neccesarry for an 8 by ten area?

    • Those are good sized spaces for a farrowing nursery. The bumper boards are a good idea in a hard wall space like this. Place them high enough so they keep the sow from hitting the wall and crushing a piglet against it. 8″ up is minimal. Base it on being a bit higher than the sows spine when she is laying down and beware of bedding buildup.

      Not every piglet born is viable. Piglets that ‘got sat on’ may also simply have died and then been crushed after that. A flat piglet does not necessarily mean crush killed by the mother.

      I would expect them to be around that much bigger. It should be growth, not fat, and that is within the range for a year.

      Good luck with your forthcoming litters!

  5. Bill says:

    I hope you’ll write more sometime about your parasite management–particularly how you use garlic. How do you feed it and how much?

    • Check out the article Worms Au Natural which talks about our parasite control. We primarily use managed rotational grazing, chickens, whey, garlic, ducks plus the copper in our soil and winter helps. Our dogs do intensive predator and small pest control which also help prevent disease from being transmitted in to our livestock – part of the biosecurity plan.

  6. phil says:

    hey walter, ive got another question for you.

    like i said i have my pigs in seperate farrowing rooms/ outside areas that are basically in total 15 feet by ten feet. so yes they are confined untill i can clear pastures and build the proper fences.

    heres the problem. water. it sucks lugging 5 gallon buckets how ever many times a day to the pens.

    so i was thinking about building some sort of water tower. i have a huge tank, atleast 1000 gallons that i wanted to use. i was going to use a manifold and attached to pipes or hoses that go into each pen, with a nipple waterer that you can buy at tractor supply firmly attached to each pen. now assuming that all works and there is enough pressure from the tank for the water to flow.

    how do i keep my water from going bad in the tank? i would be pumping the water from a pond i have close by. so there will be organic matter and whatever else in the tank. ive heard to keep it covered and dark. and some farmers have even talked about putting a few goldfish in the tank.

    and if i cant keep it from going bad..how long untill it will go bad?
    and just because it becomes stagnant in the tank, is this bad for the pigs to get that water? its not like there is any dangerous amounts of feces or anything nasty. its fresh pond water. its the same water theyve been thriving on from the pond.

    i need a little help with the tank idea. i obviously dont want to use any chemicals.

    • It would depend a lot on your temperatures. Our temps are low and the water coming out of the mountain is cold. We have setup 1,000 gallon tanks at times to hold water but mostly we do this with small ponds which are more on the order of 30,000 gallons. In both cases they are filled from springs so there is some continuous flow through here. Our issue is that sometimes some of the springs have not been sufficient for the surge needs – thus why we’ve used tanks and ponds to act as a queue to store the gradually accumulated water. We do have fish in our ponds to eat the insects. They and the frog tadpoles also eat algae. I think the biggest thing is having some fresh water coming in, the exchange. How long your queue can last will depend then largely on the quality of the water and the temperature. Covering to shade it from the sun, insulating, ground contact all help.

  7. Kyle says:

    Thanks for posting this, Walter! We have had these yellow flies on our American Guinea Hog dung for two years and I was wondering what they were and whether they were a good sign or a bad sign. So I’ll take it as a good sign, and a result of our avoidance of chemical wormers in all of our livestock.

  8. Ken in NH says:

    We’ve got thousands of them that love our pigs’ dung. I don’t give our pigs any meds unless absolutely necessary (penicillin treatment once to one sick, young pig). Not sure if I am doing good or wrong by my pigs, but I don’t even give them deworming meds, but I’ve never seen any signs of worms.
    (please tell me if I am doing wrong by them or if the worms they get are not visible to the naked eye…)

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