The answer is IMMEDIATELY.
The recommendations are based on Conducive Environments which may attract Termites. It is imperative that these recommendations are acted on straight away to lesson the chance of Timber Damage caused by Timber Pests. A mature termite colony under perfect conditions can destroy a 500mm piece 4 x 2 pine timber within a fortnight. The most common types of Conducive Environments are gardens up against walls, damp subfloors, stumps left in the ground, moisture in walls and air con or hot water systems overflowing to the ground. Removing these environments and installing a Termite Management System (Termite Barrier) is your best bet against foraging termites.