Factors To Consider Before The First Release

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Factors To Consider Before The First Release

Revision #2: Modified by on 2 Apr 2012 5:45 PM in Fly Control Instructions
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Existing Fly Problem:

Fly Predators attack the fly’s pupa (cocoon) stages only. They do not attack the adult pest flies. Thus, the adult flies currently existing must either be removed by supplemental methods or tolerated until they live out their short life span of about 21 days.

Remember, it is always better to start your releases of Fly Predators early in the fly season and prevent a buildup of flies, than to have to remove the adult flies after they have attained intolerable levels. Although the quantity of Fly Predators recommended are generally suited for most situations, occasionally larger quantities are needed for severe fly problem areas.

At the height of the fly breeding season you may need an extra shipment or two so that the Fly Predator population can keep up with the pest flies which reproduce up to 9 times faster. (That’s why we provide Bonus shipments). The female Fly Predator lays about 75 eggs with 14 to 20 days to emergence while each pest fly female can lay 500 eggs with as few as 8 days to emergence. It is due to this large reproduction capacity of the pest fly that the Fly Predators are not self-sustaining to a degree high enough to maintain full fly control and thus need to be supplemented each month of the fly season. Some of the Fly Predators will overwinter just as the pest fly does in the cocoon stage and each year they will become better established, thus control improves with time.


If you have many ants in the area where you are going to put the Fly Predators, it is best to eliminate them first, as they will eat the Fly Predators.


Fly Predators inside the pest fly pupa are very appealing to birds. If birds or chickens are eating the Fly Predators before they emerge from the fly pupa, do not spread the Fly Predators in the manure but leave them in the opened pouch hung above chicken level on a nail or thumb tack. This way they will fly to the manure as soon as they emerge. In about a week or 10 days pour the remaining contents out. Another method of protecting your Fly Predators until they emerge is to cover the fly pupa lightly with leaves, dry manure or dirt.


Unlike pest flies which can often be only slightly affected by insecticides, Fly Predators are very susceptible to these. Thus, if sprays are currently being used and the over spray will fall on a large part of the manure inhabiting Fly Predators, the sprays should be discontinued.

Generally, feeding internal larvicides to your animals will not adversely effect the Fly Predators. Occasionally manure will have enough poison residue left in it from past heavy spraying to completely kill your beneficial insects. The only solution here is to clean out and start over again.

  • Hi,

    Ready to try fly predators at my new mini farm. I cannot find anywhere when to actually start using them. I am in zip code 27613 Raleigh Nc. Can you please advise?


  • Jill,

    Most folks in your location start around March 24th.  If you would like to place an order, please give us a call at 866-404-3895.

    Thank you,