Western larch is an ecologically important tree species in the Pacific Northwest where it is prized for its timber quality, fire resistance, resiliency to injury, and fall colors. In 2018, forest officials began receiving unusual reports of top kill and mortality of western larch in the Northern Idaho area. Previous DNA from one adult moth near a western larch and one caterpillar found in the bole of the tree, found that the species attacking was Cydia rana. Subsequent genomic analysis determined the species to be in a complex known as Cydia laricana. To further verify these results, we collected eight visibly infested western larch (top kill, canker-like areas, and frass) between September and October of 2022. From these trees we extracted 23 caterpillars that represent three morphologically distinct species that also differed in relative abundance. The number of each morphotype collected was 20, 2, and 1 respectively. After extracting and barcoding DNA, the majority of the specimens were again identified as Cydia rana but three have been submitted for subsequent genomic analysis to determine if they are Cydia laricana. Collections will continue to confirm species as well as host preference.