I've never seen anything to affirm that there are particular demons devoted to certain vices or temptations. I believe in describing the lion prowling, I see demons as knowing our weaknesses and preying on them. C.S. Lewis said (and I paraphrase) One mistake Christians make with Satan is to give worry about him too much. Another mistake they make is to not concern themselves with him at all.
Satan clearly has a legion of demons he has sent out. I don't believe Satan himself cares about me, or that he even knows I exist. He's not God with omnipresence. He's one singular fallen angel. But, I'm confident he has demons on the case.
Matthew 12:
<sup class="versenum" id="en-NIV-23533">43</sup>"When an evil<sup class="footnote" value="[<a href="#fen-NIV-23533f" title="See footnote f">f</a>]"></sup> spirit comes out of a man, it goes through arid places seeking rest and does not find it. <sup class="versenum" id="en-NIV-23534">44</sup>Then it says, 'I will return to the house I left.' When it arrives, it finds the house unoccupied, swept clean and put in order. <sup class="versenum" id="en-NIV-23535">45</sup>Then it goes and takes with it seven other spirits more wicked than itself, and they go in and live there. And the final condition of that man is worse than the first."
Although I didn't particularly enjoy Lewis's "Screwtape Letters", I believe he paints a very realistic picture of the forces at work around us.