Which pests are known to affect alfalfa?

Empoasca solana, commonly known as the potato leafhopper, is indeed a significant pest affecting alfalfa. This insect feeds on the sap of alfalfa plants and can cause direct damage by weakening the plants and leading to reduced growth and yield. Additionally, the leafhopper can lead to a condition known as hopperburn, which manifests as yellowing of leaf margins and potentially significant crop loss.

In contrast, while the other pests listed can impact various crops, they are not as directly associated with alfalfa as Empoasca solana. The Russian Wheat Aphid primarily targets wheat, the Bird Cherry-Oat Aphid affects oats and other grasses, and the Brown Wheat Mite generally infests wheat. Each of these pests has its specific host preferences and does not primarily damage alfalfa as significantly as the potato leafhopper does. Hence, focusing on Empoasca solana is pertinent when discussing pests that affect alfalfa.