Which of the following statements is true about boxwood leafminer generations per year?

• A. There is one generation per year.
• B. There are two generations per year.
• C. There are three generations per year.
• D. There are four generations per year.

Answer: (A)

The pest completes its life cycle once each year in Maryland. Adults emerge in spring and lay eggs on new growth, then the hatched larvae mine the leaves, creating the distinctive blotches. After feeding, they pupate in the leaf tissue and overwinter there, emerging again the next spring to start another cycle. The length of the growing season and cold winters prevent a second full generation, so there is typically only one generation per year. In warmer climates, a second generation might occur, but not under Maryland conditions.