Question: what is the white spray released by dead fruit flies on the window glass?

[andron]

Greetings everyone,

I am new here. I registered because I am hoping someone can help me identify a phenomenon involving drosophila flies in my kitchen. Today, I looked at the window glass and saw this:

Who can identify this white spray around the dead fruit flies? I've seen this before a few times, but I couldn't find any information on it (though maybe I just used the wrong search terms).

Is it some kind of fungus?

Best regards,

andron

[mistermack]

Someone's been using cheap fly spray ?

Edited August 6, 2023 by mistermack

[andron]

7 minutes ago, mistermack said:

Someone's been using cheap fly spray ?

No one's been using anything.

[mistermack]

From the images, the white bits are more concentrated closer to the fly, and maybe a bit more around it's back end. That would match with the fly depositing them as it died, moving around to start with, and moving less and less as it got closer to death. Could be eggs, or fungal spores etc. Would need an expert or someone's who's seen that very thing previously. Or a look under the microscope. 

[TheVat]

More likely a residue left by something (mites of some kind, or small spiders?) that ate the innards of the dead fly?  

Seems unlikely eggs would be deposited on window glass.  Eggs tend to be put where there is moisture, shade, and sustenance, aren't they?

Time flies like an arrow,

Fruit flies like a banana.

- Marx

Edited August 6, 2023 by TheVat
adds

[John Cuthber]

I suspect it's the spores of the fungus that killed the fly.

[mistermack]

4 hours ago, TheVat said:

Seems unlikely eggs would be deposited on window glass.  Eggs tend to be put where there is moisture, shade, and sustenance, aren't they?

Yes, normally. But a glass window is not something that evolution prepared a fruit fly to deal with. Like moths to a lamp, they might be programmed to head for the light, to find a spot to lay their eggs. I agree eggs aren't a high probability. But I wouldn't write them off.