smudge pot

Short definition from Wiktionary

Noun

1. 1
   Kerosene flares with round bottoms and wicks in a protected cage. They were once used to mark highway construction sites and functioned as utility flares.
2. 2
   An oil-burning device used to prevent frost on fruit trees.
3. 3
   A pot of tar and oil burned to produce thick noxious smoke to discourage pests.