MSc Thesis Defence - Mugdha Stone - Department of Biology-FR

Event date(s): August 17, 2026
Time(s): 01:00 PM - 05:00 PM
Category: Fredericton
Location: Fredericton

Examining Committee

Abstract

The red pine scale (RPS; Matsucoccus matsumurae) (Kuwana, 1905) is a highly invasive insect native to Asia that is rapidly killing red pine (Pinus resinosa) trees across the northeastern United States. As of 2025, it has never been detected in Canada. However, infestations have been detected alarmingly within 50 miles of southern New Brunswick. To support timely surveillance, I tested three trap types for visual detection and specimen collection. I then developed and validated a species-specific qPCR assay to detect RPS DNA from targeted environmental DNA (eDNA) samples collected from conventional insect traps. The canopy pitfall trap collected the highest number of RPS individuals, making it the most effective option. I developed the assay primers and probe in silico to target a 242-base-pair region of the mitochondrial cytochrome oxidase I (COI) gene. In vitro testing showed that the assay reliably differentiated RPS from its main sympatric congener in the study area, the white pine bast scale (WPS; Matsucoccus macrocicatrices), demonstrating high specificity. Using a gBlock-based standard curve, I determined the limit of detection to be one copy per reaction. I validated the assay by molecular testing of eDNA samples collected from two RPS-positive sites in the United States and one RPS-negative control site in Canada. Known RPS infestations consistently corresponded with positive eDNA detections, confirming assay accuracy. Additional testing is required to broaden the assay’s applicability in other geographic regions. The assay successfully detects RPS populations at the tested sites, and the sequenced COI barcodes for both RPS and WPS provide valuable genetic reference data. Overall, this study provides the foundation for an effective and reliable approach for RPS detection and establishes a baseline for future surveillance and management efforts.

Building: Bailey Hall

Room Number: Room 102