To determine the number of parasitized fly pupae needed for your individual situation, you will need to take into consideration the number of animals, level of your current fly infestation, the size of your facility and the results you wish to achieve. The recommended start-up time is early in the spring after your last frost, three to four weeks prior to your normal fly season with distribution continuing every two to three weeks until the first frost of the fall. Release quantity guidelines are based on quantity of Fly Parasites needed to maintain control under average conditions. Warmer more humid conditions will likely require a greater quantity, with cooler dryer conditions possibly needing less. A larger area and/or an area with more abundant fly habitat will require a greater quantity. Good versus poor manure management will affect the quantities to a great extent also.

To establish control of an existing fly population, the normal procedure is to double or triple the guideline quantity for the first two shipments. This results in a number of fly parasites large enough to overwhelm the flies’ reproduction capacity until the fly population drops off. This is usually not necessary when establishing a fly parasite population at the beginning of the season if distributions are started well before flies start to emerge.
Fly Parasites limit the hatch of new generations of flies, but do not have any effect on the existing adult population. Therefore, we recommend the use of fly traps and baits to augment the fly parasites as well as using good manure management to reduce fly breeding habitat. Other livestock in the general area can produce a fly population which can migrate a substantial distance. The use of fly traps at the perimeters of your livestock area can markedly reduce this migration. Introducing your neighbors to a fly parasite Program can be to your benefit as well as theirs.

The flies’ ability to reproduce is influenced by many factors. At times, various conditions can cause a rise in the fly population resulting in the need to re-establish control as stated above. Release instructions are packaged in the first shipment of the season. They should be read and followed carefully. Proper distribution practices will have a substantial impact on the results you achieve. Establishing a properly managed Ecological Program provides you with a sensible, long-term method of fly control.

Fly parasites are shipped while they are still feeding and growing inside the fly pupa, which is their natural food. Once they are fully grown, they will "hatch" through a tiny exit hole leaving an empty shell behind. Please realize that cold temperatures will slow the insects’ development and warm temperatures will speed them up. Ideally, your insects should begin to hatch as soon as you receive them. However, due to our inability to control their temperature while they are in transit, we ship the parasites at a point in their development so the hatch occurs up to several days following delivery. Keep the closed bag in a warm room until you notice some parasites moving around inside then release as instructed. An ideal temperature for hatching of fly parasites is 70 to 80 degrees.
Do not leave the parasites in direct sunlight or intense heat.

Summer-time shipments may often bring insects that have been warmed enough to cause an early hatch. This should not present a problem and simply means that your fly control agents are ready to get to work.

If the hatch has not yet begun and conditions require delaying the distribution of the fly parasites, you may slow down the hatch by holding them at a cool temperature of 40-50 degrees for up to 24 hours then moving them back into the ideal temperature. (Do not refrigerate as this can draw moisture from the pupae and damage the fly parasites within.) This simple method will slow the insects' development considerably and can retard their hatch by as much as a week.