Physical Characteristics

The various species of blow flies are pretty easy to spot: Their thoraxes, or upper bodies, are bright metallic blue, green or black, and they’re larger than house flies, at 3/8 to 5/8 inches in size.

Blow Fly

Blow flies can indicate the nearby presence of dead animals, or animal excrement. This is where the female lays its eggs, and the larvae – or maggots – hatch, pupate and then turn into flying nuisances. Flies have been known to harbor over 100 different diseases, ranging from typhoid fever to salmonella. (To the credit of the common green bottle fly, or Lucilia sericata, studies have shown that sterile free-range L. sericata maggots can cure methicillin-resistant Staphylococcus aureus infections when they are applied to open MRSA-infected wounds; the fly larvae eat the dead tissue and infectious bacteria, allowing the healthy tissues to heal.)

Fly infestations almost always indicate some kind of sanitation problem, and with blow flies, may indicate the presence of dead animals nearby. Your Clark technician can point out what’s causing the flies to infest your property, and can advise you on how you can take care of it.

Latin name: Calliphoria vomitoria, Lucilia sericata, et al.