Abstract
The soybean tentiform leafminer, Macrosaccus morrisella (Fitch) (Lepidoptera: Gracillariidae), is native to North America where it was known to feed on American hogpeanut and slickseed fuzzybean. However, it has recently expanded its host range to include soybean, an important agricultural crop. Here, we report a new, highly contiguous genome for this species with a length of 245 Mb, N50 of 9 Mb, and 96.33% BUSCO completeness. The mitochondrial genome shares only 81% identity to its nearest relative in the NCBI nucleotide database indicating long-standing divergence or sparse sequencing in this clade. To determine whether host plant choice is genetically driven, we sequenced 18 individuals across 3 locations in Minnesota, USA, collected from both American hogpeanut and soybean plants. Genetic variation did not correlate with population structure based on either geography or host plant species (weighted FST estimate: 0.0058). As a secondary measure, we independently assembled complete mitochondrial genomes from all individuals and observed no delineation between host or location. The overall lack of detectable population structure at the nuclear and mitochondrial genome levels suggests a large population with flexible dietary preferences and does not show evidence of genetically driven host preference.