2-Pentylfuran: an aggregation attractant for wireworms

Wireworms (Coleoptera: Elateridae) are generalist insect pests that aggregate and feed on the roots of various crops, including maize. It remains unclear how they find and choose host plants. Several studies have focused on volatile organic compounds released by roots infested by wireworms, revealing the presence of 2-pentylfuran. We hypothesized that 2-pentylfuran could be a key aggregation cue that attracts wireworms towards roots colonized by conspecifics. In a series of olfactometer assays, we first investigated whether the larvae of click beetles indeed use volatile organic compounds (VOCs) as cues to locate maize roots that are already under attack by conspecifics. Surprisingly, wireworms were found to not only orient towards conspecific larvae feeding on the maize roots, but also to larvae alone. VOCs collections from plants and larvae revealed the presence of 2-pentylfuran, particularly in treatments where larvae were present. In subsequent dual-choice olfactometer assays wireworms exhibited significant attraction to 2-pentylfuran. These results imply that 2-pentylfuran is involved in wireworm aggregation behaviour, and open up opportunities for the development of an attract-and-kill strategy.