Mosquito Trap Items needed: 200 ml water 50 grams of brown sugar, 1 gram of yeast (yeast bread, found in any supermarket) and a 2-liter plastic bottle. How to: One. Cut the plastic bottle (PET type) in half. Storing the neck portion: 2nd. Mix brown sugar with hot water. Let cool. When cold, pour in the bottom half of the bottle. 3rd. Add the yeast. No need to mix. It creates carbon dioxide. 4th. Place the funnel part, upside down, into the other.