In ornamental gardens, which pest is associated with the introduction of insect eggs into plant tissue?

The introduction of insect eggs into plant tissue is a characteristic behavior of the Japanese beetle. Adult female Japanese beetles often lay their eggs in the soil, but when they are feeding on ornamental plants, they can also damage the tissue by burrowing into it to lay eggs. This not only causes direct damage to the plants but can also open them up to secondary infections and other pests, leading to further health issues within the ornamental garden.

In contrast, the other pests listed do not typically exhibit this behavior. Spider mites feed on the plant sap and can cause stippling or webbing but do not lay eggs within the plant tissue. Brown patch is a fungal disease associated with turfgrass and does not involve insect eggs. Leafhoppers are known for their sucking mouthparts, which they use to feed on plant sap, but they do not introduce eggs directly into the plant tissue. Therefore, the behavior specific to the Japanese beetle clearly identifies it as the correct choice in the context of the question regarding ornamental gardens.