Thank you for your informative site. I would like to know if ALL life stages of fleas are killed when I wash laundry in hot water and dry in a hot dryer. I understand that adult fleas, larvae and eggs will be killed but I know cocoons are very tough to kill. I have some bedding and old clothing that my cat has slept on a lot and I am sure they were the source of fleas. I am wondering if I should just throw them out instead of laundering. For example, I washed a blanket in hot water twice (and dried) and I still see white spots on it. I’m nervous about bringing it back into my house. Thanks for your input.
Yes, all the life stage should die. The cocoons won’t be able to survive the laundering and drying process. The cocoon wouldn’t provide any significant protection to the fleas. You won’t need to throw away the blankets and garments.
I’m not sure what the white spots are, but I doubt they are related to fleas. If you’d like, you can take some pictures of them, upload to imgur.com, and I can confirm it.
Cocoons are difficult to get rid of because larvae tend to spin cocoons at the base of carpets. The silk fibers get incorporated into the carpet matrix, making them hard to remove. Sprays and vacuuming can’t reach them well.
I hope this helps, and I apologize for the delayed response.