Clyde from Tallahassee, Fl writes,
Can fleas be resistant to Tengard SFR + Nyguard IGR?
I am using Tengard SFR + Nyguard IGR for fleas. I sprayed baseboards and the tile floors and vacuum every few days. I am still seeing fleas. Do you think the fleas might be resistant to this insecticide?
Fleas are most likely not resistant to the chemicals like Tengard that you are using. Flea elimination can take several weeks and it is normal to keep seeing fleas even after the initial spray. Flea eggs and pupa are protected from all of the insecticides that you can use and they will not be exposed to the application until they reach the adult flea stage. Once the adult fleas are exposed to the application they will usually die within 24 hours. You should only treat once every 14 days and continue to vacuum every day. It is also very important to treat all pets and all outside areas where pets frequent to avoid reintroducing fleas to the indoor areas.
Answer last updated on: 06/27/2012