The effects of topically-applied double-stranded RNA pesticides on Myzus persicae
| dc.contributor.author | Joseph, Kelvin Tom | |
| dc.contributor.examiningcommittee | Wilkins, Olivia (Biological Sciences) | |
| dc.contributor.examiningcommittee | Lee, Jae-Hyeok (Biological Sciences) | |
| dc.contributor.supervisor | Whyard, Steve | |
| dc.date.accessioned | 2025-05-20T19:13:13Z | |
| dc.date.available | 2025-05-20T19:13:13Z | |
| dc.date.issued | 2025-03 | |
| dc.date.submitted | 2025-05-20T19:13:13Z | en_US |
| dc.degree.discipline | Biological Sciences | |
| dc.degree.level | Bachelor of Science (B.Sc.) | |
| dc.description.abstract | The green peach aphid (Myzus persicae) is a major agricultural pest, causing billions in crop losses and contributing to global food insecurity. Increasing incidences of insecticide resistance and off-target effects highlight the need for alternative control methods. RNA interference (RNAi), a gene-silencing mechanism triggered by exogenous double-stranded RNA (dsRNA), has emerged as a promising approach to species-specific pest control. Topically applied dsRNA offers a non-GMO alternative to traditional pesticides, selectively inducing mortality in pests by targeting essential genes. One such gene, Chitin Synthase (CHS), is crucial for the insect exoskeleton, tracheae, and gut. However, dsRNA penetration through the aphid’s hydrophobic exoskeleton remains a challenge, necessitating delivery enhancements like surfactants. This study tested two dsRNA structures—long linear dsRNA (210 bp) and short paperclip RNA (pcRNA, 25 bp)—targeting CHS, with and without the surfactant Silwet. Third-instar aphids were topically treated with a dsRNA droplet, and their survival and fecundity were monitored over eight days. Several bioassay optimizations were implemented, including stretching diet packets, treating third instars instead of adults, filter-sterilizing diets, and chilling aphids before treatment. Bioassays demonstrated that dsRNA + Silwet significantly increased aphid mortality, whereas dsRNA alone and all pcRNA treatments had no significant effects. No significant fecundity reduction or CHS gene knockdown was observed. While only a single gene target was assessed, findings suggest RNAi-based pesticides hold potential for aphid control, and Silwet improves dsRNA efficacy. Further research on optimizing dsRNA formulations could enhance their application as next-generation pesticides. | |
| dc.identifier.uri | http://hdl.handle.net/1993/39085 | |
| dc.language.iso | eng | |
| dc.subject | green peach aphid | |
| dc.subject | Myzus persicae | |
| dc.subject | pest control | |
| dc.subject | RNA interference | |
| dc.subject | RNAi | |
| dc.subject | double-stranded RNA | |
| dc.subject | dsRNA | |
| dc.subject | chitin synthase | |
| dc.subject | Silwet | |
| dc.title | The effects of topically-applied double-stranded RNA pesticides on Myzus persicae | |
| local.author.affiliation | Faculty of Science::Department of Biological Sciences |