A Pest or a Friend? By Steve Kenyon
Our industry spends millions and millions of dollars every year on fly control. Back rubbers, oilers, sprays, fly tags, pour ons, traps and anything else someone has invented to address this symptom. My question to you is, “Is it working? Do we have fewer flies today?”
I think I already know your answer. Have you ever heard the definition of insanity that is you do the same thing over and over and expect different results? That’s what we do in our war against flies. We don’t seem to like flies very much.
I, on the other hand, like flies. Actually, I like the fly larvae because they do a good job at eat- ing manure. They help decompose the dung and recycle the nutrients. I want flies on my ranch. They are part of my work force and I consider them one of my employees, just like every other critter that lives on my ranch. Every critter on my ranch has the right to reproduce.
A “Pest Issue” occurs when we get too many of one species in an environment. The conditions
are favoring one species so they become prolific. Nature needs balance. If it is out of balance, I would bet that it is our fault. Our industry only looks at one piece at a time instead of looking at the whole.
Step back and look at the whole system to see why one species has the advantage. Most of the time in agriculture, I believe that it is caused by our management changing the environment to suit our needs. In many cases we actually cause the lack of favorable conditions for the predator. Without the predators, the pest becomes a pest.
Let’s look at our friendly neigh- borhood fly. I want her to lay eggs in the manure. I want the eggs to turn into larvae and I want the lar- vae to eat the manure. No harm, no foul yet, right?. At this point, I need a predator to show up and eat the larvae. I do not want them all gone as I do need some of the flies to become adults so that we again have eggs to be laid in the next set of dung pats.
Predators are usually looked at as a bad thing in our industry. I disagree. Let’s look at just a few predators that might be able to help us out. Every environment is differ- ent and you might not have these critters in your environment but I bet if you looked into it, you could solve the symptom of a pest issue by addressing the problem, instead of looking for a quick fix to address the symptom.
Without the predators, the pest becomes a pest. The parasitic wasp is a great predator. There are over 80 different types of these guys. This wasp shows up around a dung pat and searches for a larvae. One example, it will sting the fly larvae and paralyze it and then deposit its own larvae inside the fly larvae. At this point the wasp’s larvae will eat the fly larvae to develop into an adult. A job well done by one of my employees.
To keep employees happy and healthy, we need to make sure they have favorable working conditions. The issue they have with agriculture is that these wasps are far more susceptible to chemicals used on the farm than the flies are. In our failed attempts to control flies, we kill off the wasps.
Dragonflies are also great employees. The adult dragonfly can capture and eat many different types of flying insects, including flies. They are very agile fliers and have incredible eyesight. Having a strong population of dragonflies on your ranch is a great way to deal with flies. The difficulty here is that to get a two week life span of the adult dragonfly, it takes up to four years in their teenage aquatic nymph stage before they become adults. This means we need to take care of our riparian areas to make sure these teenagers have the chance to become adults. Talk about a long term breeding program.
How about my favorite employee of all time? The dung beetle. How does he help with flies? Indirectly, he helps us by just doing his job. His job is to degrade the dung pat. And if we have a healthy environment suitable for them to work in, the dung pat will be degraded quite quickly. If the dung pat is gone, so is the breeding ground for the flies.
They can also help us directly. The larvae of dwellers, one type of dung beetle, are also predators of the fly larvae. The beetle larvae will feed on the fly larvae. Another type of dung beetle, tunnelers will move the fly eggs below ground and disrupt the flies’ life cycle. Another win for us in our battle against flies.
A very visible predator here at Greener Pastures Ranching is the infamous cow bird. I love to see these guys flying around my herds. I will have thousands of them with one herd. I enjoyed watching these employees work when I was a kid but then for years I never saw them. Once we went chemical free on our ranch about 15 years ago, cow birds again have desirable working conditions. They are very effective at fly control.
Last summer I came across three bats snuggled into a door crack of one of our sheds. They were pretty desperate for a place to sleep. Bats are great at pest control as they can eat up to nine times their body weight a day in insects. You guessed it, I have three bat houses installed out in a pasture now to give them a great day’s rest so they can have a hard night of work. These are test houses for them. If we get some happy tenants, we will be installing a lot more bat houses at all of our pastures.
Need I go on? Flies are part of our ecosystem. Their job is to eat poop. Is anyone looking for a job? They only become a pest if we unbalance the system. We spend too much time on searching for symptom solvers and not enough time looking for the problems on our farms and ranches. We need to take care of the whole system.
Steve Kenyon ranches in Busby, Alberta, Canada, and can be reached at skenyon@green- erpastureranching.com. Www. greenerpasturesranching.com or on Facebook at Greener Pastures Ranching. His book The Calendar of the Year-Round Grazier is available from the SGF Bookshelf.
