Get Ahead of Next Fly Season with the 30/30 Approach

Published on Mon, 07/16/2018 - 3:12pm

  Get Ahead of Next Fly Season with the 30/30 Approach

 Fly infestations greatly impact production on dairy farms. The house, stable, face and horn fly are the most common pests affecting cattle, each posing distinct and significant threats to the animal’s comfort and productivity. Without a proactive fly management program in place, reductions in weight, milking productivity and disease resulting from flies can take a significant toll on the comfort of animals and an operation’s bottom line.

The key component of a thorough integrated pest management (IPM) program designed to control flies around cattle is the use of a feed-through solution such as ClariFly® Larvicide. While it is important to administer ClariFly® Larvicide throughout the peak fly season, knowing when to start and stop feeding the product on your dairy can greatly influence its overall effectiveness.  

To maximize control of costly flies with ClariFly® Larvicide, operations need to limit the number of overwintering pupae that emerge in spring, jumpstarting the fly population. However, precisely planning exactly when to target the overwintering pupae can be difficult given the unpredictability of seasonal weather patterns. To account for this uncertain nature of frost dates, Central Life Sciences recommends taking a “30/30” approach to fly control on dairy operations.

The “30/30” program encourages operations using ClariFly® Larvicide to start including the products into their feed mix early in the spring, 30 days before flies begin to appear through 30 days after the first frost when cold weather reduces or ends fly activity. This ensures an ideal window of treatment with the products that protects against an unpredictably early or late start to the winter and spring seasons.   

To help determine the ideal timing, producers should begin feeding ClariFly® Larvicide approximately 30 days before average daytime daily temperatures typically reach 65° F. This is the point when overwintering flies emerge to mark the start of the fly season. The process should be maintained into the fall season until 30 days after first frost has been recorded.


Countless studies have shown that flies can cause serious economic damage to dairy operations. The effects are very real to producers, and the importance of controlling fly populations has never been more critical. When incorporated into an integrated pest management (IPM) program, the use of ClariFly® Larvicide with a “30/30” approach can help producers account for the unpredictability of the seasons and significantly lower fly populations while increasing cow comfort, productivity and profitability.

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ClariFly® Larvicide is a feed supplement that prevents house flies, stable flies, face flies and horn flies from developing in and emerging from the manure of treated cattle. Unlike conventional insecticides that attack the nervous system of insects, ClariFly® Larvicide works by interrupting the fly’s life cycle, rather than through direct toxicity. When mixed into cattle feed, ClariFly® Larvicide passes through the digestive system and into the manure. The active ingredient in ClariFly® Larvicide is able to disrupt the normal molting process of the fly larvae with only very small concentrations.