What do Lyctid beetles lack that prevents them from infesting softwood?

Lyctid beetles, commonly known as powderpost beetles, are specifically adapted to infest hardwoods rather than softwoods. The key reason for this limitation lies in the structure of the wood itself. Hardwoods contain large, open pores that are essential for the beetle’s life cycle, as these pores provide the necessary environment and food sources for their larvae.

In contrast, softwoods have fewer and smaller pores, which do not meet the requirements of Lyctid beetles for successful infestation and development. The lack of suitable pores in softwoods means that the female beetles cannot lay their eggs effectively, nor can the larvae find the food they need to thrive. Consequently, this anatomical feature directly impacts the beetle's ability to infest softwoods, making it a critical factor in understanding their ecological niche and behaviors.