What is the key to preventing subterranean termite infestations according to construction guidelines?

The key to preventing subterranean termite infestations according to construction guidelines is centered on avoiding contact between earth and wood structures. Subterranean termites thrive in soil and typically access wooden structures from the ground. When wood is in direct contact with the soil, it provides an easy pathway for termites to invade and cause damage. By implementing design features that create a barrier or separation between the wood and the soil, such as using concrete foundations or ensuring proper ventilation, the likelihood of termite infestations is significantly reduced.

This approach is fundamental to effective pest management in construction because it addresses the termites' natural behavior and habitat. In contrast, the other choices do not provide a viable solution to termite prevention. For example, using decorative wood could potentially attract termites, while keeping wooden structures in shade does not prevent them from accessing the wood. Planting bushes near foundations may create moisture-rich environments that can actually attract termites rather than deter them. Therefore, maintaining a separation between wood and soil is the most effective preventive measure against subterranean termites.