To identify moth infestation, click here.
First, vacuum any excess signs of moths from both the front and back of the rug with a deep cleaning air power vacuum. Then, use a beater vacuum from the reverse side to agitate eggs out from the base of the pile. Repeat use of air vacuum on the front of the rug. Creasing the rug length-wise (with the direction of the warps) as seen below exposes more deeply into the pile allowing for more thorough vacuuming. Once you are sure all eggs and signs of moths are gone, the rug should be safe.
Natural remedies for moth infestation: Refer to the Textile Museum on Proper Freezing methods!
In serious cases of infestation, a "moth wash" at a professional oriental rug cleaning plant may be in order. In this process, the carpet is submerged in a specific solution to eliminate current and future possibilities of infestation.
Preventative measures: Use either moth flakes or cedar. Moth flakes may come in direct contact with carpet. Cedar must not come in contact with the rug as color may run from the wood to the carpet. If you are planning to store the rug, cedar will need to be replaced every 6 months when wrapped with the carpet, whereas moth flakes will remain active for upwards of 18 months.
A Video from Dusty Roberts of RugBadger.com and RugLoverMary with Barry O'Connell of SpongoBongo for Oriental Rugs and Persian Carpet Guide
The FREEZE method: Watch starting at 1:23