Will <i>Pseudacteon</i> phorid flies (decapitating flies) sting or bite? Are decapitating flies harmful?

A Pseudacteon phorid fly approaches a fire ant for landingNo, Pseudacteon phorid flies cannot sting or bite, because they do not have stingers or biting mouthparts, nor are they attracted to humans or pets.

Pseudacteon phorid flies, also known as decapitating flies, were imported from South America as biological control agents of imported fire ants.

  • They are very small, about the size of a fire ant head, and are hardly noticeable.
  • They cannot sting or bite, because they do not have stingers or biting mouthparts.
  • Pseudacteon phorid flies are not attracted to humans or pets, only to fire ants.

Before they were initially released, tests were conducted to determine if they were attracted to other insects or food items including raw vegetables, fresh fruit, raw meat, prepared foods, and even carrion. Pseudacteon phorid flies are attracted only to Solenopsis fire ants. In fact, several native species of Pseudacteon phorid flies attack native fire ants.

Pseudacteon phorid flies should not be confused with other phorid fly species. At least 3,000 described species exist in the family Phoridae, all of which are known as phorid flies even though they have very different life histories.  In January 2012, it was reported that the phorid fly Apocephalus borealis  attacks honeybees.  Pseudacteon phorid flies will not attack honeybees. 

Related Content


Porter, S. D., and L. E. Gilbert. 2004. Assessing host specificity and field release potential of fire ant decapitating flies (Phoridae: Pseudacteon), pp. 152–176. In R. G. Van Driesche, T. Murray and R. Reardon [eds.], Assessing host ranges for parasitoids and predators used for classical biological control:  a guide to best practice. FHTET-2004-03, USDA Forest Service, Morgantown, West Virginia. PDF

Find more information about fire ants in eXtension’s Imported Fire Ant Resource Area

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