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Perimeter treatments that use vaporized or liquid repellents or pesticides are just now being developed for flies, although various products on the market also claim effective-
ness against mosquitoes. Jar traps and sticky traps have been used successfully to prevent or minimize the passage of flies, but the former would not be recommended for use in
urban areas.
Some pest management companies apply various pesticides and growth regulators to out- side walls of commercial buildings that might be used by flies as resting sites. Some of
these sites are near rear entry doors and treatments are thought to prevent fly entry into the structure. The effectiveness of such treatments has not been evaluated.
7.8.8. Crack-and-crevice treatments
As the name implies, crack-and-crevice treatments are usually treatments with pestici- des placed in cracks and crevices of walls. Generally, however, these treatments do not
apply to flies, because in most instances flies are not found in such locations. The excep- tion might be overwintering flies. If this is the case, standard liquid-formulation pestici-
des could be used to kill the flies. If flies are entering a structure, the entryways should be closed, as suggested in subsection 7.8.3. If cracks in walls, around windows and under
doors are large enough to allow fly entry, these should be repaired by the party respon- sible for maintenance.
7.8.9. Biological control
Biological control is not recommended at present for urban settings. This is because most of the available options work best against the immature stages of the fly and essentially,
it is the adults that are causing the problems. If immature stages are found in temporary urban habitats, these can usually be eliminated quickly by nonbiological means. The
exception might be their elimination in compost piles.
The most promising biological organisms being investigated for urban use against adult flies are entomopathogenic fungi. A number of these have been identified and tested, but
spore preservation techniques need to be improved, so spores remain viable in the field for long periods. This will allow the use of feeding or infection stations, where flies are
attracted to bait and become infected with a fungus.
7.8.10. Attractants
Attractants are desperately needed for fly management in urban areas. Several housefly attractants are available for agricultural use, but these are in many cases too odoriferous
for use indoors. Attractants for use indoors must compete well with common indoor odours, such as those from pastries in bakeries and meats in delicatessens. Commercial
buildings in some locations are air-conditioned and the air inside can be completely repla- ced up to five times an hour. Thus, any attractants designed to be used with indoor traps
must be dispensed in appropriate quantities. Various pest control companies have added housefly sex pheromones to the glue boards in their light traps as attractants; however,
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7.8.6. Traps
Many types of trap are used in urban areas for managing flies inside and outside of com- mercial and private dwellings. These include: ultraviolet light traps; sticky traps; jar or
bag traps; window traps; and sticky tubes, tapes and ribbons.
7.8.6.1. Ultraviolet light traps
These traps attract flies with long-wavelength ultraviolet light and then either kill them by electrocution or trap them on boards covered with glue. These traps are the main
method used by many commercial pest management companies to control flies in com- mercial establishments, particularly supermarkets and restaurants. They are not recom-
mended for individual houses or apartments. There are many trap models to choose from; however, to maximize the number of flies captured, the location of their placement
is critical. Whenever possible, traps should be mounted within a metre of the floor, and models having an open front with a direct display of the lights are generally most effec-
tive. Traps that kill by electrocution should not be used indoors, especially in food pre- paration or consumption areas. When electrocution occurs, very small particles of the
insects and any associated microorganisms are projected into the air where they may contaminate food or be inhaled by people Urban Broce, 2000.
7.8.6.2. Sticky traps
Several sticky flytraps are commercially available. These can be used in commercial loca- tions or in backyard garden areas to capture flies outside without pesticides. These traps
are also suitable for surveillance work.
7.8.6.3. Jar or bag traps
These traps are charged with an attractant mixed with water to draw flies inside the trap, where they die. These traps can be used by commercial establishments, around trash com-
pactors and in garbage collection areas. They can also be used outdoors by private indi- viduals – for example, in garden areas. No pesticides are used these traps.
7.8.6.4. Window traps
These traps can be used in commercial establishments and in homes, to capture flies that enter buildings and eventually come to the closed, glass windows. These are passive traps
and flies attracted to windows eventually fumble down into the traps and become cap- tured on a sticky strip. Some of the traps fit in the corners of the windows, and others
merely fit along the sill. Window traps capture the flies on glue boards out of view and without pesticides.
7.8.6.5. Sticky tubes, tapes and ribbons
These traps, hung at or near ceiling level, can be used to capture flies in commercial kit- chens, away from food preparation areas. If fly populations are large, these traps should
be changed frequently, as they become filled or nearly filled with flies. When selecting sites in which to hang these traps, it should be kept in mind that warm temperatures in
food preparation areas can cause the adhesives to liquefy and drip onto surfaces below.
7.8.7. Perimeter treatments
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• Refine our knowledge of the infestation rate of natural fly populations in urban areas.
7.10 Conclusions
For dealing with fly infestations, the following items are suggested. 1. Proper sanitation is the key to fly control. Deny flies access to food, shelter and a place
to lay their eggs. 2. Do not allow flies to come in contact with contaminated substances and thus conta-
minate themselves. 3. Although management of adult flies can provide temporary relief, the location and eli-
mination of development sites for immature stages is the best method for long-term control. Although people make the distinction between urban and rural flies, flies do
not, so fly management in urban areas may involve surveillance at and management of potential fly-producing sites outside the urban perimeter.
4. Prevent flies from entering buildings, by keeping doors closed and window screens in proper repair.
5. If flies do enter structures, eliminate them with traps or other suitable methods as quic- kly as possible.
6. If people experience fly problems, particularly if such problems are associated with ill- ness, health authorities should be contacted immediately.
7. Health authorities with entomological expertise should have properly trained person- nel to identify flies and assess the extent of fly outbreaks with or without associated
pathogenic organisms. Should their assistance be needed, health authorities should have contacts with outside entomologists and medical personnel.
8. There is a need to improve education in entomology at the biological branches of uni- versities. Such education will establish and produce expertise and knowledge, which
is currently being eroded dramatically, because of the lack of financial support. 9. Public awareness and educational programmes are essential to minimize the trans-
mission of pathogens by flies, especially in times of disaster. It is particularly impor- tant to teach the benefits of exclusion of flies from foods and from food-preparation
and dining areas.
10.Communities should develop fly-management guidelines that indicate action thres- holds for adult populations and that suggest corrective measures to be taken when
thresholds have been exceeded. Corrective measures may include legal action to be taken against individuals or companies that fail to control flies when a nuisance situa-
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increases in efficacy have not been substantiated.
7.8.11. Air flow
To prevent or minimize flies from entering structures, airflow from air curtains can be used around doorways Mathis, Smith Schoof, 1970. In some places, air curtains are
required on service entrances where doors remain open for long periods. Air curtains can also be used over entrances used by customers, although customer acceptance is
usually low. New research is revealing improved methods for air curtain use that will maximize results and improve customer satisfaction. Also, ceiling fans can be used
indoors to prevent flies from entering and resting in selected areas, such as on counters or in food preparation areas in commercial establishments. Airflow does not need to be
extremely high to keep flies away. Fans can be used in conjunction with ultraviolet light traps in a push–pull system, by placing fans over areas where fly exclusion is desired and
placing light traps in nearby dead air spaces, to capture the flies.
7.9. Guidelines for fly control
The following guidelines are used to control flies. • Monitor regularly the urban fly populations, with a special focus on hospitals, retire-
ment facilities, kindergartens and the like. Evaluate their pathogen load and determine the percentage of infected flies.
• Devise a system to better estimate when disease outbreaks are related to pathogens transmitted by flies.
• Restrict pesticide usage to outbreak scenarios. Determine the peak season of various pest species, to predict potential outbreaks. These flies could then be managed with the
focused use of pesticides during a small window of time. • Develop improved attractants to use in traps and baits.
• Improve trap designs. • Improve fly-exclusion and trapping devices for use around entrances.
• Develop effective perimeter barriers or perimeter control techniques that do not involve the use of pesticides.
• Educate the public about the biology, ecology and control of nuisance flies, the role of flies as transmission agents and the need for proper sanitation to prevent flies from beco-
ming contaminated. • Refine our knowledge of fly biology and of their habits and behaviour in urban areas.
