It sounds a no-brainer. Offer the flies something tasty to eat that doesn’t keep moving and swishing its tail, and they might prefer to feed there. However, a recently published study suggests that it is notthat simple.
Tracey L Tam and Saundra Tenbroeck of the Department of Animal Sciences, University of Florida, Gainesville, and Jerome Hogsette of the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology in Gainsesville, conducted a study to investigate whether sticky traps could be used to help protect horses from the bites of the stable fly, Stomoxys calcitrans.
Stomoxys calcitran causes irritation and distress to a variety of animals (and humans). Adults of both sexes are vicious blood-feeders and inflict painful bites with their long piercing proboscis. Their preferred feeding sites are on the lower legs of horses and cattle, and around the ankles in humans.
The study set out to see how well commercially available fly traps placed at various distances from a horse provide protection from stable fly bites.
The researchers applied fluorescent dust to the eight chestnut mares used in the study. This allowed them to identify which flies had fed off the horse. Different coloured dust was used on different days.
They found that more than 40% of flies captured on traps placed closest to the horses were marked and had fed on the horse before getting caught. So, the traps had not stopped the flies visiting the horses.
Some trapped flies were marked with more than one colour, indicating that flies could visit the horses more than once without being trapped.
Some marked and unmarked stable flies showed signs of blood in their guts indicating recent feeding.
The authors conclude that, although the traps caught ample numbers of stable flies, they did not prevent them feeding on the horses.
They suggest: “More work is needed to determine optimal trap placement and densities required to maximize stable fly management with traps.”
For more details, see:
Can attractive sticky traps be used to protect horses from the bites of Stomoxys calcitrans (L.) (Diptera: Muscidae).
Tam TL, Hogsette J, TenBroeck S.
J Econ Entomol. 2019 Jun 22. pii: toz134.