Lyctids primarily feed on which of the following?

Lyctids, commonly referred to as powderpost beetles, primarily feed on wood that contains starches and cellulose. They are particularly drawn to hardwoods, which have a high starch content that they utilize for growth and development.

The correct answer focuses on the types of organic materials these beetles target. While they may incidentally consume small amounts of other substances, their primary diet centers on the carbohydrates found in the wood. This behavior is significant in understanding the biology of lyctids and their impact on wooden structures, as they can cause considerable damage to furniture or timber by tunneling through the wood in search of food.

Recognizing that lyctids are specifically adapted to process the starches and cellulose in wood helps clarify why options that list proteins, fats, or sugars without emphasis on their primary food source (wood) do not accurately reflect the feeding habits of these pests. Thus, the understanding of their actual dietary preferences aligns with the correct identification of their primary food sources.