Submitted to www.whatsthatbug.com
Louse Flies
(12/22/2006)
I live in Los Angeles in a lower apartment.
These thing look like "Flying Spiders"? They are hard to kill, and appear to be able to produce web? Whatchya think? Thanks
Chris

Hi Chris,
These are Louse Flies in the family Hippoboscidae. According to Charles Hogue in the wonderful book Insects of the Los Angeles Basin: "Occasionally, a person hiking or working in mountainous areas wilolo notice a small (1/8,. or 3 mm, long) flattened brown fly that has landed on his skin or clothing. Looking much like a winged tick, the fly clings tenaciously or crawls sluggishly for a moment before flying away. This is one of the two common local species of Deeer Louse Flies (Neolipoptena ferrisi or Lipoptena depressa), which normally live as ectoparasited on deer. ... Upon successfully finding a deer, it immediately crawls through the hair to the skin and begins to suck blood. Here it remains as a permanent parasite, soon losing its wings through wear. ... All Louse Flies are blood suckers, although none feeds regularly on humans. They may transmit disease between wild animals but do not to and between people." You did not provide us with any specific information regarding where in Los Angeles you live. If near Griffith Park or some other deer habitat, it will strongly support this identification. There are also other Louse Flies that are bird parasites. We cannot locate any information regarding the possible web building you mentioned, and suspect that the Louse Flies were found in the proximity of legitimate spider webs. Eric Eaton wrote in: "Hi, Daniel: You are correct about the louse flies. What a cool find! We'd love to have more images at Bugguide (hint, hint, Santa)."

Thanks Guys
I live in a large apartment building in Cerritos Ca, Now that I may have identifiied my pest, now what? Thanks again Cheers!
Chris