What are common signs of tree pests?

Leaf discoloration and premature leaf drop are indeed common signs of tree pests. When pests infest a tree, they can cause stress that affects the tree's overall health. Discoloration often occurs due to the interruption of photosynthesis or damage caused by the pests feeding on the leaves. This damage can manifest as yellowing, browning, or spots on the leaves. Additionally, pests can cause the tree to drop leaves prematurely as a response to stress or to protect itself from further damage.

The other options represent conditions that are typically associated with healthy tree growth or factors unrelated to pest infestations. For instance, increased fruit yield and vibrant foliage are indicative of good health rather than pest infestation. The growth of new branches and healthy bark are also signs of a thriving tree. Reduced water intake could signify other issues, such as drought stress or root problems, but it does not directly indicate the presence of pests. Understanding these signs helps in identifying and managing pest problems effectively in forestry and tree care.