The sun is shining. Toms and hens gobble happily. The whole turkey world rejoices! It’s a new dawn for beetle and fly control. The past year or two has seen the introduction of seven. Count them, seven new insecticides! We should all be excited about the possibilities, right? Not so fast. Truth be told, we do have seven new products but the promise is not quite so promising.

Three (Credo, Oxyfly, and Neporex) contain active ingredients that are familiar to the poultry industry (imidacloprid, lambda-cyhalothrin and cyromazine, respectively). Of these, Credo and Neporex are formulated differently and one (Neporex) has an expanded label that now includes turkeys. One of the new products (Standguard) contains gamma-cyhalothrin, which is a variant of an old active. Another (Actishield) simply adds the active ingredient bifenthrin to the already crowded field of pyrethroids. Finally, two (Elector PSP and balEnce) are entirely new active ingredients (spinosyn and Beauveria bassiana) that also represent two new classes of insecticide.

There are some differences in utility as well. Two are registered only for fly control (Neporex and balEnce) and one exclusively for beetle control (Credo). The others are labeled for both flies and beetles.

Most importantly for the turkey industry, first hand information about the efficacy of the new products is limited and ranges from very good to average to poor to unknown. The author has not looked at every new product but there is plenty to talk about. There is a beetle control study underway, and other field trials in the wings. There is a list at the end of this article that should be helpful: it contains the old fly and beetle control products that are still labelled, and most of the new arrivals.

The authors have a trial running at two turkey brooder hubs to evaluate the efficacy of five of the newer products: Standguard (gamma-cyhalothrin), Oxyfly (lambdacyhalothrin), Actishield (bifenthrin), Elector PSP (spinosyn) and Credo (imidacloprid). The details are not covered here but Credo applied at the label rate did a very good job of suppressing adults and larvae for an entire five-week brooder cycle. Actishield and Elector did moderately well for the same period compared to a positive control (Ravap), while Standguard and Oxyfly performed only slightly better than the control. The authors are finishing up the second flock now, and the results look similar. They hope to have the final results published early next year.

They say they have yet to look at the products for fly control but plan trials for both Neporex and balEnce. Part of the reason for the trials is to figure out how to best plug these products into a fly management programme for turkeys. The fungus in balEnce is known to be very effective against flies, and this new product is available in a granular bait and spray formulation. It has also received labelling for use in organic production. Neporex is a water-soluble granule that may be used dry or applied as a spray. The active, cyromazine, has been an effective fly larvicide in layers and broiler breeders for years, and is likely to be useful in turkey production.

Long-term control of the most persistent insect problem – the darkling beetle – in grow-out is unlikely. It remains true that given the limited opportunities for treatment during the long production cycle. A single treatment with Credo will last about six weeks but what about the next six weeks and more? There are few products that may be used while the birds are present. Of these Elector PSP, is perhaps the most effective for larval control; Actishield and Rabon/Ravap as targeted treatments for adult control along walls and under feeders. The good news is that beetle control in brooder houses is another matter entirely. A single treatment of Credo provides excellent control for an entire brooder cycle. Other products such as Elector PSP for larvae and Actishield or Rabon/Ravap for adults and larvae may provide good larval suppression with a properly timed second application during the flock cycle.

In short, there is some hope that we can effectively suppress beetle populations in brooder houses and still have some flexibility to manage insecticide resistance. Sounds simple enough, but the new products are only part of the solution. Application is just as important.

The new application paradigm is low volume these days. The author admits that he preached a “use what you’ve got” sermon for years, believing that 100 to 200 gallons of spray per house was acceptable if that was all a grower could do given the equipment at hand. He thought a goal of 100 or less gallons was certainly a good move, but did not push the idea very hard. Not surprisingly, many companies shifted to dust application and lower spray volumes, in part to limit the amount of moisture in the turkey house. The recent move to lower the volume of water used in turkey houses was a good thing for beetle control as well. Briefly, lower volume application most often requires different equipment, and that different equipment is generally able to deliver treatment more precisely. There is an additional benefit in that droplet size can also be reduced and applied more uniformly across the litter. Better precision and smaller droplet size helps insure that beetles and larvae have the best possible opportunity for exposure to a lethal dose of the insecticide.

Methods of Application

The author favours pull-type sprayers that have a 7- to 8-foot boom (articulated is helpful for wall coverage, but not necessary), 5 or 6 small bore, flat fan nozzles, a 25- to 30-gallon tank, a roller pump and gasoline engine sufficiently large to power the sprayer. An auxiliary spray wand can be attached to treat corners. Such a sprayer should be able to hold 30 to 60 psi pressure in operation and be towable behind a small tractor or ATV. The goal of such a sprayer is to put 25 or fewer gallons of spray exactly where you want it. Variations of this design will do just as well so long as a fixed arrangement of wide coverage, fine spray nozzles is at the center of the design.

Other approaches can work nearly as well, but are often less precise. Air blast sprayers or powered backpack misters/foggers are ultra-low volume (ULV) applicators that can quickly deliver ultrafine droplets throughout the house. The volume of water can be as low as two to six gallons. A variation on this approach is to use a house washer equipped with misting nozzles. This approach still uses a considerable amount of water, however. The main drawback of mists or fogs is that a fine aerosol is more difficult to control. A fair amount finds its way to walls, curtains and ceilings. That is acceptable but that insecticide is of more use on the litter. Further, if you have calculated the rate of application based on the square footage of the floor, the actual rate per unit of area could be considerably lower than intended. In short, just be sure to do the math before you fill the tank.

One final thought about ULV application. There may be an opportunity to move treatment closer to the time of placement using a powered backpack mister. Treating within a day or two of placement will extend the period of control by almost a week. The application could be made after brooder guard is up but before poult feeders were put in place.

Wand sprayers of any kind – but especially small pump sprayers (backpack or canister) &ndash: should only be used to apply material over relatively small areas. They are well suited for treatments along feed lines, around posts and along interior walls. However, attempts to treat an entire house with such sprayers are a gamble. It is very difficult to ensure uniform coverage throughout the house, and wherever coverage is shorted or absent, it is a safe bet that the beetles will proliferate.

Zones of Application

What about maximizing efficacy while limiting the area of application? The current field trial demonstrates that by applying an effective treatment to areas where we know beetle activity ramps up early in the flock cycle, we can dramatically reduce the population in untreated areas as well.

The zone of maximum beetle activity in turkey brooder houses extends from the walls to the feed lines, with the greatest activity occurring beneath the brooders within a few weeks of placement. The Credo treatment appeared to have not only suppressed beetle activity in this zone, but the untreated area down the centre of the house as well.

Can we do the same with less persistent insecticides by timing a secondary application when birds are around three weeks of age? Maybe. Other data suggest that it just might be possible, but there is work to do in fine tuning this approach.

Seasonal Considerations and Managing Insecticide Use

Darkling beetle populations typically decline somewhat with the onset of cold weather. The magnitude of that decline is largely dependent on the type of housing (curtain-sided versus solid-wall construction) and the age of the building.

The author is a fan of halting beetle treatments in late summer/early fall and letting the cold weather suppress their numbers naturally. There may be added benefits from cold season treatments. Treatments while numbers are naturally suppressed might prove very effective in delaying the onset of and reducing the size of beetle infestations coming into the spring and early summer. Credo could be especially effective in that respect.

Consider treating for two brooder flocks in the February-to-April window to reduce beetle populations as far as possible. Follow-up treatments might then be delayed for one or more flocks, and allow the use of other registered products to control infestations for the remainder of the year. For example, if beetle populations were very low after two Credo treatments, Elector PSP or Durashield might extend satisfactory control for additional flocks.

Two late summer/early fall Credo treatments might work equally well, suppressing beetles without further treatments for the rest of the winter. Come spring, another active ingredient could be used once the beetle population begins to surge.

Both approaches should be evaluated to see which approach works best. Regular monitoring (visual or with traps) will be necessary to assess the affect of winter treatments and determine when to begin warm season treatments.

There is an apparent inconsistency with this approach relative to insecticide rotation and resistance management. However, limited use of Credo followed by a rotation to other classes of compounds is acceptable so long as the treatment program remains with the alternate class until the next Credo window. To illustrate, if Elector PSP follows the initial treatments until it is again time for the two Credo treatments, the next rotation should come from a third class of chemicals (the organophosphate, Durashield, for example). Such an approach ensures a period of rotation for all the products that is sufficiently long (nine months for Credo; more than a year for Elector and Durashield). Remember too that successful suppression of beetles during the winter might well eliminate the need for one or more treatments during the warm season.

February 2009

Further Reading

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