Factors Affecting Numbers of House Flies (Diptera: Muscidae) Captured by Ultraviolet Light Traps in a Large Retail Supermarket

The house fly, Musca domestica L., is an international nuisance and vector of numerous pathogens that cause disease syndromes in humans and animals. In urban areas, fly exclusion is a major part of the pest management program at many commercial establishments. If flies elude the exclusion techniques, a system for fly management inside the building is the next line of defense. Permission was given to evaluate the fly management system consisting of 12 GT-180 and 6 MX-360 ultraviolet (UV) light traps inside of a large supermarket for 8 wk. GT-180 traps mounted 2 m high on walls captured significantly fewer flies than MX-360s, larger portable traps placed on the floor. Both glue boards in GT-180 traps captured similar fly numbers. In the MX-360 traps, mean fly numbers captured by the two vertically mounted glue boards combined were not significantly different from those captured by the single lower horizontal glue board. Changing from white to black glue boards significantly reduced fly numbers captured by both traps. Three of the six traps capturing the largest mean fly numbers were in the Bakery, followed by the Deli. A total of 3,626 house flies (453/week) was captured during the study. Changes in weekly fly populations inside the store were visibly obvious because fly numbers were so high. Difference in flies trapped because of trap location and height, and glue board color are further discussed.