THE ASIATIC GARDEN BEETLE, MALADERA CASTANEA, IS AN ANNUAL WHITE GRUB SPECIES THAT WAS INTRODUCED TO THE U.S. IN 1921 AND HAS SINCE SPREAD TO 25 STATES AND 2 CANADIAN PROVINCES. HISTORICALLY A PEST OF TURFGRASSES, ORNAMENTALS, AND VEGETABLES, M. CASTANEA RECENTLY EMERGED AS A NEW PEST OF FIELD CORN IN PREDOMINATELY SANDY SOILS OF INDIANA, MICHIGAN, AND OHIO. GRUB FEEDING IN THE SPRINGTIME OFTEN COINCIDES WITH THE PLANTING OF FIELD CORN. GRUB FEEDING ON FRAGILE SEEDLING ROOTS CAUSES PLANTS TO STUNT, WILT, DISCOLOR AND ULTIMATELY DIE. HIGH GRUB DENSITIES RESULT IN EXTENSIVE PLANT STAND LOSSES EXCEEDING 40%, AND INSECTICIDES ARE EITHER SEEMINGLY INEFFECTIVE OR HAVE NOT BEEN EVALUATED SPECIFICALLY FOR M. CASTANEA, AS ANNUAL WHITE GRUBS ARE COLLECTIVELY TARGETED. IT IS INTERESTING THAT M. CASTANEA POPULATIONS HAVE ONLY RECENTLY INFESTED FIELD CROPS AND ONLY IN THE GREAT LAKES REGION IN SPITE OF THEIR BROAD DISTRIBUTION AND LONG HISTORY IN THE U.S. REGARDLESS, GENETIC RESOURCES ARE SCARCE FOR THIS SPECIES AND NEED TO BE FURTHER INVESTIGATED. WE HYPOTHESIZE THAT THESE BEETLES COMPRISE A GENETICALLY DISTINCT POPULATION AND PROPOSE TO USE MOLECULAR GENETIC TOOLS TO COMPARE M. CASTANEA POPULATIONS FROM DIFFERENT NORTH AMERICAN REGIONS. THIS SERVES THE LONGER-TERM GOAL TO UNDERSTAND WHY M. CASTANEA HAS EMERGED AS A NEW PEST. OUR OBJECTIVES ARE TO (1) DEVELOP MOLECULAR MARKERS FOR M. CASTANEA, AND (2) USE THE RESULTING MARKERS TO ASSESS NORTH AMERICAN POPULATIONS FOR HABITAT-SPECIFIC VARIATION AND/OR GEOGRAPHIC VARIATION.TO ASSESS THE POPULATION GENETICS OF M. CASTANEA POPULATIONS THROUGHOUT NORTH AMERICA, WE PROPOSE A NOVEL APPROACH THAT UTILIZES NEXT GENERATION SEQUENCING TO IDENTIFY MOLECULAR MARKERS, OR MORE SPECIFICALLY SINGLE NUCLEOTIDE POLYMORPHISMS (SNPS), FOR THE FIRST TIME IN THIS SPECIES. SNPS ARE SINGLE MUTATIONS FOUND THROUGHOUT THE GENOME THAT CAN BE USED TO ASSESS HOW SIMILAR INDIVIDUALS OF A GIVEN SPECIES ARE. IN OTHER INSECTS, SNPS HAVE BEEN USED TO DETECT INSECTICIDE RESISTANCE, DETERMINE THE ORIGIN OF INVASIVE SPECIES, AND IDENTIFY RELATIONSHIPS BETWEEN DIFFERENT POPULATIONS AND HOST PLANTS CHOICE. IN BRIEF, WE WILL USE SPECIFIC LOCUS AMPLIFIED FRAGMENT SEQUENCING (SLAF-SEQ) WHICH IS USED TO PRODUCE A REPRESENTATIVE SNAPSHOT OF M. CASTANEA'S GENOME. THE GENETIC SNAPSHOTS, OR LIBRARIES, OF BEETLES SAMPLED FROM THE GREAT LAKES REGION WHERE INFESTATIONS IN FIELD CROPS OCCUR, MID-ATLANTIC REGION WHERE M. CASTANEA WAS ORIGINALLY INTRODUCED, AND THE SOUTHEAST AND NORTHEAST WHICH EXPERIENCE DIFFERENT CLIMATES, WILL BE COMPARED. ANY RESULTING GENETIC VARIATION ASSOCIATED WITH ONLY GREAT LAKES POPULATIONS COULD INFORM US AS TO WHETHER GENETICS, OR ENVIRONMENTAL VARIABLES, ARE FACILITATING INFESTATIONS IN FIELD CROPS. IF GENETICS ARE RESPONSIBLE, THEN THIS INFORMATION CAN BE USED TO DETERMINE WHETHER OTHER POPULATIONS ON THE FRINGE IT ITS GEOGRAPHIC DISTRIBUTION ARE AT RISK OF INFESTING FIELD CROPS AND ALLOW FOR THOSE STATES TO BE PREPARED. THE ABSENCE OF GENETICALLY SIMILAR POPULATIONS IS ALSO INFORMATIVE AS IT WILL INDICATE WHETHER SOMETHING ELSE IN THE ENVIRONMENT IS RESPONSIBLE, SUCH AS SOIL TYPE OR MANAGEMENT TOOLS LIKE INSECTICIDES. THE RESULTS FROM THIS PROJECT WILL BE PRESENTED AT THE 2021 ENTOMOLOGICAL SOCIETY OF AMERICA'S ANNUAL MEETING IN DENVER, CO, THE OHIO STATE FARM SCIENCE REVIEW, AND A COMPREHENSIVE M. CASTANEA FIELD DAY OPEN TO UNIVERSITY RESEARCHERS, EXTENSION EDUCATORS, AND LOCAL STAKEHOLDERS IN NORTHWEST OHIO, AND PUBLISHED IN AN EXTENSION FACT SHEET, AND PEER-REVIEWED JOURNAL.