High Five

PCOs can resolve virtually any fly problem successfully by implementing a five-step IPM program that includes inspection, identification, determining threshold levels, control and follow-up.

Since before recorded history, mankind has been plagued by flies. Whether sharing his food or shelter with them, or suffering from the countless diseases they transmit, our ancestors have had to contend with flies for thousands of years. The Hebrew term for the devil, Beelzebub, is translated as “Lord of the Flies.”

From Egyptian hieroglyphics and the writings of Aristotle, to modern battles trying to suppress them on every continent, flies have always been linked to mankind, most commonly as a pest.

Do flies deserve such a lowly reputation? Yes! They are far more than an irritation. They affect our health in several ways. First is the annoyance factor. A single fly can drive one crazy as it pings around a lampshade. Second is the allergic reaction they can cause in humans. A fly’s body is covered with tiny hairs. These can break off, become airborne and inhaled, or become imbedded in the eyes, nasal passages or ears, causing an allergic reaction in many people. Next, many species of flies are parasitic, laying their eggs in the nasal passages, eyes and ears of animals and even humans. Finally, disease transmission by flies can cause serious illness and even death. We have no way of knowing how many cases of dysentery and salmonella occur each year due to food contamination by flies.

The order Diptera, which is comprised solely of the flies, is the fourth largest order of insects with more than 110,000 species. There are probably less than 20 that require serious pest management measures in and around structures. The most recent edition of the Handbook of Pest Control by Arnold Mallis divides flies that infest structures into five separate groups: filth flies, small flies, overwintering flies, biting flies, gnats and midges.

The filth flies include the housefly, little housefly, blow flies and flesh flies. The small flies include fruit, vinegar and pomace flies, as well as phorid flies and moth flies. The primary overwintering flies are the cluster fly and face fly. Biting flies include mosquitoes, stable flies, deer flies, horse flies and black flies. Finally, there are a variety of gnats and midges that are generally pests in and around aquatic areas, often being attracted to the lights of buildings.

AN IPM APPROACH. With so many different types of flies in and around structures, how do we develop a pest management program for them? We do it by incorporating IPM principles into our treatment programs. IPM is a process that involves five steps — inspection, identification, development of threshold levels, employment of two or more control measures and follow-up evaluation.

An IPM approach can and should be employed in every situation. It is an effective approach because it makes no difference what insect is causing the problem or the type of structure involved. We simply place these two factors into the IPM “template” and proceed ahead. Then, by considering any restrictions that might be inherent in the account, we can determine the appropriate control measures. Let’s walk through the IPM process step by step and see how it applies to fly control in and around structures.

STEP 1: THE INSPECTION

A thorough inspection is critical to the success of any management program. The inspection should be an orderly, organized procedure designed to determine several important things about the account, including how the flies gained access to the structure, the location and extent of the infestation, conducive conditions, sanitation deficiencies, etc. It should include all of the premises, both indoors and outdoors.

Every level of the structure should be inspected including attics, living spaces, basements, crawlspaces, etc. No area should be overlooked because an infestation may begin in one location where favorable environmental conditions exist and quickly move to another part of the building. That’s why identifying all current and potential breeding sites is essential when designing a control program.

Monitoring traps can be very effective when inspecting for flies. These may include any number of different light traps for attracting and killing flying insects. When correctly placed, such traps can provide an “early warning system” alerting you to infestations.

Record everything you find. Clear, thorough information will enable you to evaluate the entire account and to review your findings with the customer. A floor plan for large commercial accounts is a must. Also consider the use of a sanitation report to point out deficiencies that need to be addressed by the customer.

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STEP 2: IDENTIFICATION

Identification is an integral part of any IPM program. This knowledge enables you to determine what control measure to employ and when, where and how to employ them. Without a thorough understanding of the pest’s habits, life cycle, habitat and biology, you cannot implement a successful control program.

In addition, several states require that both the target pest and the chemical used in the account must be listed on the treatment record. Since specimens may be damaged and thus difficult to identify, use a “holistic approach” when attempting to identify the target pest. Simply put, by considering where it was found, what it was doing and other characteristics of the infestation, you can often make a positive identification. Once a pest has been correctly identified, its food preferences, breeding and harborage sites, behavioral patterns, biology, habits and damage potential may be determined, as well as the recommended control options.

STEP 3: THRESHOLD LEVELS

Simply put, a threshold level is the number of pests — flies in this case — that can or will be tolerated in a particular account or location within that account. Depending upon the fly species, account in question, regulatory restrictions and the customer, this number may vary. For example, a single housefly in a loading dock area of a hospital will be tolerated and probably ignored. The same fly in an operating suite is intolerable.

Keep in mind, however, that the threshold level should be established prior to determining the control measures necessary.

STEP 4: CONTROL MEASURES

Unlike many conventional pest control programs that rely primarily upon pesticide applications, an integrated pest management (IPM) approach first considers non-chemical control measures. The primary objective of an IPM approach is to design a program that uses more than a single strategy or control measure. The typical IPM program includes sanitation, mechanical controls, cultural controls and chemical controls. A brief review of each of these elements follows.

Sanitation. Quite simply, sanitation is the elimination of water sources, pest harborage sites and food so as to inhibit survival. To be effective, it requires the cooperation of the customer who is normally the one who provides the sanitary measures. Flies, like all living things, have four basic requirements: food, water, shelter (pest harborages, breeding sites, etc.) and conducive environmental conditions (temperature).

All sanitation practices should be aimed at reducing or removing at least one of these essential requirements. Ideally, all four need to be addressed for long-lasting fly management. Many sanitation practices can be used in an integrated pest management approach for the control of virtually any pest. These include:

• Removal and proper disposal of waste foodstuffs and garbage.
• Timely cleaning and storage of all cooking utensils.
• Elimination of standing water or the source of leaks.
• Degreasing of equipment, washing of all floors, counters and other surfaces that might accumulate foodstuff.
• Trimming or removing of dense foliage around buildings which may collect trash and, hence, harbor flies.
• Cleaning up of trash around the building and its perimeter.
• Keeping garbage in closed containers.
• Providing drainage of standing water.
• Disposing of animal waste and spilled animal food or feed.

Mechanical controls. Mechanical or physical control involves the use of traps, caulks, seals or barriers to prevent flies from entering, establishing and living in an undesired location. It may include exclusion, removal or trapping.

Exclusionary measures may include caulks, seals, gaskets, screens or any other device to prevent flies from entering the building or establishing breeding sites within the building. It may also include the use of air doors in larger accounts. Thorough inspection, combined with correct identification of the species, will allow you to locate potential breeding sites and exclude flies from these locations.

Removal of harborage sites, food sources and the flies themselves can effectively reduce breeding populations. An effective method of removing all stages of flies is through vacuuming. There are several types of vacuum devices available that can be used to rid the premises of not only living adults but also dead flies and the hairs and other body parts that may be present. In addition to reducing the breeding population, vacuuming can also create a healthier environment for the customer.

Trapping may involve the use of various types of devices. These may include sticky traps, baited traps or light traps. Many traps combine two or more strategies. The use of light traps to capture flies is one of the most commonly used mechanical control measures. They can be an effective way of reducing the adult population; however, correct placement and frequent inspection and glueboard replacement is essential.

Cultural controls. Cultural control measures are those that get customers to do things differently than they may have always done them in the past. It involves manipulation of the fly’s environment to make it less favorable for development. It may also be referred to as habitat modification or environmental alteration. To accomplish this, the customer may have to change some of his or her normal practices or habits and thus make it harder for populations to become established or to spread. Examples may include getting the customer to change storage practices or something as simple as keeping the back door to the restaurant closed.

Chemical controls. The final type of control method is chemical. Although non-chemical control measures are normally employed first, there may be times when insecticides will have to be the first control strategy used because of the immediate need to significantly reduce or eliminate a fly population. This may be a situation that threatens public health or safety.

One of the most common applications for fly control in structures is ultra low volume (ULV) treatments including the use of total release aerosols, controlled release aerosols or special equipment designed to distribute “micro-droplets” of insecticide. The latter may be hand-held or automatic fly machines that dispense a small amount of insecticide at regular intervals. This type of application ensures that insecticide reaches all areas of a room; however, it will generally be effective only for the adult stage.

Other formulations and locations may include residual liquids applied to windowsills and spot treatments applied outdoors where flies land to rest.

Other insecticide applications may include the use of residuals in cracks and crevices where phorids or sewer flies may be breeding and the use of baits in outdoor areas. For a close look at available formulations, please read “How to Choose the Formulations You Use” in the Formulations editorial supplement NEW on PCT Online.

STEP 5: FOLLOW-UP EVALUATION

The final step in the IPM approach to fly control is the evaluation of effectiveness. Follow-up inspections will enable you to assess and adjust the control measures that have been employed. There are several reasons for reinspecting the account including:

• Determining the effectiveness of previous procedures.
• Identifying overlooked areas.
• Eliminating entry points.
• Enhancing program effectiveness.
• Reapplying or revising any pest management procedures as necessary.
• Maintaining good customer relations and satisfaction.

Simply put, reinspecting allows you to determine your effectiveness, modify your program and satisfy your customer.

IPM IS THE KEY. It’s important to remember that effectiveness is enhanced when you can combine as many control measures as possible. For example, an IPM approach to managing houseflies might include sanitation to remove food and water sources; mechanical controls such as screens and air doors to prevent entry and vacuuming to remove dead flies; cultural controls such as making sure that food is properly covered and stored after use; and chemical control measures including the application of residual insecticides to outdoor areas where they may rest and to windowsills and a ULV application to kill all adults inside.

Managing fly infestations in and around structures can be a frustrating task if it is not properly implemented. But by employing an IPM approach, you can effectively manage any fly species in any account. This approach consists of a thorough inspection to determine how the flies may have entered, their food sources, breeding sites and sanitation problems; proper identification of the fly species; determining how many are acceptable in that particular location; employing two or more control measures; and following up with regular inspections to ensure effectiveness.

Knowing the structure, the fly species and the restrictions inherent to that account allows you to determine the appropriate control measures, resulting in a successful treatment.

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HOW FLIES AFFECT HUMAN HEALTH 1. Annoyance 2. Allergic Reaction 3. Parasitism 4. Disease Transmission

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CRITERIA FOR SELECTING CONTROL MEASURES 1. Least disruptive to natural controls; 2. Least hazardous to human health; 3. Least toxic to non-target organisms; 4. Least damaging to general environment; 5. Most likely to produce a permanent reduction of the pest population; 6. Easiest to carry out effectively; 7. Most cost-effective over the short- and long-term.

Dr. Mark S. Lacey is Eastern Technical Services Manager for Paragon Professional Products.