Gene-silencing technology to protect forests from invasive pests

A University of Kentucky forest entomologist is developing a pest-control method that uses RNA interference (RNAi) to target harmful forest beetles while limiting impacts on the surrounding ecosystem. The research, led by Dr. Lynne Rieske-Kinney, explores the potential of RNAi to combat the emerald ash borer and southern pine beetle.

Dr. Rieske-Kinney has devoted nearly a decade to studying RNAi as a management tool for these forest pests. The technique involves creating double-stranded RNA that corresponds to a specific gene sequence in the target insect. When the insect consumes the RNA, its cells halt production of the related protein, ultimately leading to the insect's death. Because the RNA sequence must closely match the target gene, RNAi is highly specific and minimizes the risk of affecting other organisms.

Researchers have conducted studies to assess the potential effects on non-target organisms for RNAi treatments targeting both pests. They have also found that these treatments can coexist with biological control agents against the emerald ash borer. For this pest, researchers are investigating treatments that protect individual ash trees, with results indicating that RNA delivered through foliar, bark, or root applications can remain active in trees for at least 30 days. The team is now investigating whether protection can last for an entire growing season or longer.

The ultimate goal is to provide season-long protection against the emerald ash borer through a single application. Dr. Rieske-Kinney adds that achieving three years of protection would be comparable to the duration provided by current chemical insecticides for ash protection. For the southern pine beetle, researchers are taking a broader approach by utilizing fungal partners associated with the beetle to produce the RNA.

These fungi could potentially spread the gene-silencing effect as beetles move through forests, allowing for a more forest-scale protection strategy.

While emerald ash borer control focuses on protecting individual trees, the research for the southern pine beetle aims to protect entire forests. Both challenges, however, share the common goal of employing this gene-silencing technology in a highly targeted manner to safeguard trees from destructive insects.