Which of the following is a characteristic of wood-destroying beetles?

Wood-destroying beetles are characterized by several distinct features, and one of the most notable is their segmented clubbed antennae. This feature helps in the identification of these beetles, as the antennae are an important morphological characteristic that differentiates them from other insect species. The segmented structure allows for a precise identification because different beetle families have varying antennae shapes and structures.

In this context, the other characteristics mentioned relate to common misconceptions or specific details that do not universally apply to all wood-destroying beetles. For instance, while some beetles may be associated with softer woods, many also affect hardwoods; hence, stating they feed on softwood only is inaccurate. Circular holes are often associated with other types of wood-boring insects. Lastly, although wood-destroying beetles can be found in water-damaged wood, they are not exclusively found there, as they can also infest dry wood under certain conditions. Therefore, the unique feature of segmented clubbed antennae stands out as the definitive characteristic for identification of wood-destroying beetles.