Location: Mosquito and Fly Research Unit
Title: Evaluation of traps for monitoring higher Diptera Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 27, 2013
Publication Date: N/A
Technical Abstract: The two main members of the higher Diptera for which monitoring traps have been developed (at least in countries where tsetse does not exist) are the house fly, Musca domestica, and the stable fly, Stomoxys calcitrans. Both flies are major pest species in the US and elsewhere and the development of efficacious traps is warranted by their large populations. The best house fly traps tend to be olfactory in nature. The Captivator trap and the larger Terminator trap use a liquid bait that serves as the attractant.Flies enter the tops of these traps and cannot find their way out.There are other traps on the market with similar designs, but the Farnam bait so far attracts the most flies in comparative tests. In a Captivator Trap, a 1-inch (2.5-cm) layer of flies is approximately 50,000. After flies are removed and counted, traps can be re-charged by adding about 2 inches (5 cm) of water along with a measured amount of liquid attractant. Captured flies can be separated from their liquid using a strainer. Counting the captured flies is not a favorite procedure because of the combined odors of the attractant and the dead flies. Traps operating on the same principle come in a variety of shapes. The bag trap must be hung on a wall or fence. The Trap-n-Toss can be hung or placed on the ground. Unlike the Terminator and Captivator traps, neither of these traps is designed to be re-used. Pesticide-treated blue-black cloth targets have been evaluated as attract and kill devices for house flies. Although house flies are attracted to these devices in sufficient numbers, it is difficult to find pesticides to which house flies have not yet developed resistance.Using long-term residual pesticides in the field for house flies is not a good idea. Traps for the stable fly are exclusively visual. No chemical attractants have yet been identified that can compare with the visual traps. The attractant is sunlight reflected in the ultraviolet range from the surface of the traps.Although CO2 can enhance the numbers of flies captured by visual traps, the slight increase in flies does not justify the effort.Stable fly is currently the most serious rangeland pest of livestock in the US. Besides being a serious blood feeder, stable flies cause cattle to bunch. Bunching is a defensive behavior but the heat generated by the cattle being so close together causes more weight loss than the blood feeding of the flies. With stable flies, both sexes are blood feeders. These flies typically feed on the lower part of the legs causing animals to stomp their front legs and swish their tails low to protect their rear legs. The Olson Sticky Fly Trap is the Standard surveillance trap for stable flies in the US. It is made from Alsynite fiberglass, which reflects sunlight in the UV range and attracts flies to the traps. A clear adhesive-coated sleeve is placed over the fiberglass to catch the flies. Blue-black cloth targets have been developed for stable fly management. These targets are treated with 1% lambda-cyhalothrin and can remain active in the field for four months.Versions of these are sold commercially by Vestergaard and other companies for management of tse-tse flies. To provide stability in winds we developed these targets in two cylindrical forms: large, and small. They attract similar numbers of flies per square surface area and there are no differences between the blue & black colors together and blue or black separately. The KnightStick is a relatively new trap on the market. It is made of PVC pipe and has a sticky wrap made from thin packing foam. When we compared the KnightStick with the Olson trap, the Knight Stick captured significantly more stable flies. An Olson trap covered with a KnightStick sticky wrap captured 3 times as many stable flies as an Olson trap covered with its own clear sticky wrap. We began to suspect that the KnightStick sticky foam wrap was very attractive by itself. This became more evident in later tests at a zoological park where the KnightStick sticky wrap was used on the KnightStick trap and wrapped around plastic barrels with and without blue/black targets. We have also wrapped the KnightStick sticky wraps around the propane tanks of the Mosquito Magnet traps and catch stable flies, biting midges and various species of tabanids and chrysops. The Florida Fly Baiter has been in the press lately so just a quick word about this device. It is not really a trap but an attract and kill device. Pesticide must be applied weekly to the black cloth strips, and the pesticide currently used is imidaploprid. House fly resistance to imidacloprid is becoming ever more common. The Florida Fly Baiter was covered with Olson clear plastic sticky wraps and evaluated at two heights against the Olson trap and the KnightStick trap. Fly populations were low when these tests were conducted so mean separation was not possible. However numerical values were highest for the KnightStick and Olson traps and lowest for the Florida Fly Baiters. Additional studies are planned. In summary, house fly traps are olfactory and stable fly traps are visual. Captivators and Terminators work well for house flies and Olsons and KnightSticks work well for stable flies. Florida Fly Baiters did not compare favorably with KnightSticks and Olson traps.