Invasive species, Genetics, Wolbachia
Operophtera brumata, also known as the winter moth, is a Geometrid native to Eastern Europe. It was introduced to North America in the early 1900’s, and over the last decade has become an invasive species in New England. The moth’s larvae defoliate a variety of hardwood and fruit bearing plants, resulting in high stress on leaf regeneration and eventual death for the trees. This can be an economic problem for farmers who grow apples and blueberries. This study aimed to better understand the moth’s invasion regarding its endosymbiosis with the bacterium, Wolbachia pipientis. Wolbachia is a common endosymbiont of arthropods and causes reproductive abnormalities in many species of Lepidoptera. The infection rate of the bacteria in O. brumata varies across populations (up to 25% of moths infected). We tested samples from populations in Europe, Massachusetts, and Rhode Island for the presence of Wolbachia by polymerase chain reaction (PCR) using primer sets for 3 genes, wsp, 16S, and ftsZ. After troubleshooting the DNA extraction and PCR protocols, we found one positive sample from Europe (Republic of Georgia) and a 0% infection rate from the New England populations. We sequenced and aligned our PCR products with a positive control (gift from J. Anderson, U.C. Berkeley) and found high conservation with consensus sequences for W. pipientis in GenBank. This information will be included in a larger data set from North America and Europe provided by our collaborators (N. Havill, U.S.D.A. Forest Service, Hamden, CT and J. Elkinton, U. MA. Amherst). Future work will include sequencing similar PCR products from these samples to identify the strains of Wolbachia. This will help to trace the invasion of O. brumata throughout New England and analyze the endosymbiont’s population structure around the world.