On the fly

Glue boards, light traps and multi-catch traps are your first line of defense in minimizing flies and other pests in plant environments

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The ideal place to locate an ILT is where insects are congregating. A very thorough inspection can determine the best location. Look for signs of fly rest areas, including the presence of "specs," which are fecal material. Place the ILT as close to these areas as possible. Keep in mind that there are often several such locations in a given facility. The resting areas may change throughout the day as temperature and light patterns shift.


Further, different fly species are attracted to lights located at different heights. Daytime flying insects, such as the housefly, are caught in the so-called "strike zone", the space from the knees to the shoulders. This range, three to six feet, is where ILTs should be placed, if day flyers are the only target. For nighttime flying insects, such as moths, ILTs should be wall- mounted eight to ten feet off the floor.


Depending on the facility, you most likely will have several species of flying insects. Be creative. You may need ILTs that are on in the daytime, and a separate set that is on at night, or at varying times of day. Your pest control technician should do a complete site survey prior to recommending and installing units.


The areas under the mounted units must also be considered. Although ILTs have a glue board in them to catch and hold insects, they should never be installed over food contact surfaces, such as prep tables, prep/wash sinks or processing conveyor lines. If service is missed and the glue on the board starts to dry, the insects may fall out of the units. Not all insects that die in an ILT are caught on the glue board. If the airflow in the facility is moving across the front of the unit, it can blow out loose insects.


Again, insect light traps should be considered a monitoring device. Analyzing the contents of the traps should provide clues about the possible source of an infestation. Knowing some basic biology of common flying insects in your region will likewise help pinpoint the source. Keep a record of the catch and analyze the trend. If an increase in a given species occurs at the same time each month or year, take a proactive approach.

Drain Flies

Drain flies -- meaning common nuisance flies, fruit flies, phorid flies, and moth flies -- are another common problem in food and beverage processing plants. Drain fly larvae thrive on the organic debris that builds up in drains and other locations. In addition to drains, they can be found in sewage filters, the water traps of plumbing fixtures, and in built-in sinks and garbage disposals. Phorid flies breed anywhere there is decaying organic matter.

These can often be found in more than one area of a facility, and their breeding grounds are usually well-concealed. As a result, they can be extremely difficult to control. Never assume that drains are the only potential source of infestation.

The treatment of these pests is particularly challenging because pesticide application in drains is not always a sound strategy. Many pest control companies can provide environmentally friendly solutions that organically break down drain grease and grime, thus removing the drain flies' feeding source. These materials contain no pesticides, but instead incorporate naturally occurring enzymes and bacteria to remove grease and grime build-up in drains. While most of these compounds are approved for use with plumbing systems, the manufacturer's specifications should be checked prior to use.

Because they act over time, these compounds may require multiple applications to penetrate small cracks and crevices in flooring. Applications of these products can be as simple as adding the compound to mop water, or as intensive as dismantling drains and apply it with scrub brushes.

Heat treatments

Not all pests that fly can be called flies. Many stored-product insects can attack raw goods as well as finished product. Treatments for these types of insects have changed greatly.

With the phase-out of methyl bromide looming, food processors are looking to less conventional pest management techniques, such as heat. Heat treatments are sometimes employed by organic food processors, and by large food processing and grain storage companies, as part of their IPM programs.

As an alternative to conventional fumigation methods, heat offers a number of advantages:

-         It delivers a 100 percent kill ratio because it eliminates all stages of insect life.

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