Mitochondrial DNA introgression is largely asymmetric. Crickets with G. firmus ancestry at nuclear markers (hybrid index = 1) often had G. pennsylvanicus mtDNA haplotypes.

 
 
  Part of: Byerly AR, Jenck C, Goetz ARB, Weissman DB, Gray DA, Ross CL, Maroja LS, Larson EL (2023) Geographic variation in phenotypic divergence between two hybridizing field cricket species. Journal of Orthoptera Research 32(2): 189-200. https://doi.org/10.3897/jor.32.90713