Unknown Fly from Arizona

Subject: Diptera mystery – what kind of fly is THIS??
Location: Phoenix, Arizona
March 17, 2017 5:39 pm
Hi,
I am plagued in my apartment by these flies that are appearing out of nowhere, starting about two weeks ago. I kill them when I see them and I have already killed two “pregnant” females. In spite of my search, I cannot figure out the species and I need to know how dangerous they might to me and my pets. I tried to take a picture but the pic came out so badly, all you can see is a black blob. Here is what I know:
– they give birth to live maggots
– the maggots are snow white
-. Physically, they are built like blue bottle flies
– they are about 1/2 inch to 3/4 inch long
– completely black on the body, no markings are present and there is no iridescence
– large red eyes that do not touch
– noisy flyers ( in fact, that’s how I find them, I hear them before I see them)
– fast flyers and agile in flight
– attracted to light
– I noticed a few hairs on the upper body near the joint that attaches to the lower body; they appeared to be black
– wings are greyish and semi-translucent
I do have one dog and one cat, so animal waste is sometimes present, but I clean the litter box regularly and always change out the puppy pads immediately. I put the waste in sealed plastic bags which are scented, then put the sealed bags in a larger scented bag which I then tie shut until I take it out. My apartment smells like a combination of bleach and flowers. So what kind of fly likes this??
I don’t think they are flying in from outside; I think they are breeding inside. I can’t figure out where. If I can identify the species, maybe I will have an easier time finding out where and how they are reproducing and finally get rid of them. I never saw them or heard them until the start of March, when I finished my spring cleaning. Can they cause myiasis? If not, then how can the maggots survive in a clean apt? There numbers seem to be steadily increasing since I cleaned. I want to figure this out before I am completely infested with flies, yuck! All of my questions will be answered if I can figure out what this mystery species is. Please help me if you can!
Signature: Concerned in Arizona

Dear Concerned in Arizona,
We need a better image to make an identification.  Louse Flies in the family Hippoboscidae give birth to live maggots, and they are pictured on BugGuide where it states:  “Females rear one offspring at a time, the larva feeding in utero from special “milk” glands. The mature larva is ‘born alive’ and immediately pupates in the soil (or on the host in some cases). Most are host specific on bird species, with a few occurring on mammals.”

Hi!
Thank you for your quick response!  I’ve got one (that I saw – Lord knows how many there actually are) flying around my living room right now!  I have locked myself in my bedroom and put duct tape over the door seams.  I went out for one moment and it flew right at me!    I was armed with nontoxic plant oil fly spray which kills on contact and sprayed right at it – that was the only thing that protected me.  the spray repelled it long enough for me to run back in my bedroom, but didn’t slow it down.  whatever it is, it sure is hardy.  I misted my entire apt with permithrin/raid 48 hours ago but it is still here and active as ever!
I know – that pic is bad.  I don’t think I can do any better though, because my phone camera is the only camera i have and my phone is cheap.
No, it can’t be that louse fly, because for the two females I’ve disposed of, they each had more than 5 maggots coming out.  A single maggot getting born, somehow wouldn’t bother me like seeing 7-8 wriggling white protrusions from a black fly’s back end all struggling to break free at once.  At least one fly with maggots was depositing bots in my bedroom.  Hopefully, whatever bots she dropped are dead now…
I’m doing as much research as i can, and I’m guessing it’s a flesh fly of some sort… The only thing is that it is all black from what I could tell.  And it seems attracted to me, but doesn’t match the description of any biting fly that I’ve read about.
I wonder if I should be worried about cutaneous myiasis, since flesh fly maggots eat both dead and living tissue.
I wonder if it could be a rarer fly that is not usually seen??
The mystery continues…
Thank you,
Still concerned

We are sorry, but we are unable to provide any further assistance.