Fungus gnats

I shot this photo Oct. 21 on our copper canyon daisy and posted it on Bugguide.net, hoping someone could tell me about the spit-looking liquid. Turns out I piqued more interest in the insects, which were IDed as dark-winged fungus gnats: "Looks like mainly male sciarids (Diptera: Sciaridae) to me. I have never heard nor read about this behavior. Probably a female got stuck and the males were attracted by her pheromones (but this is pure speculation). Did you collect the 'gnat spittle'?" –Bjoern Rulik

Bad me–I didn't do a good job at following up on his request. Sorry, Bjoern!