Associate Professor University of Vermont Burlington, Vermont, United States
Abstract: Jumping worms, Amynthas agrestis, A. tokioensis, and Metaphire hilgendorfi are earthworms that are invading forests, gardens, and horticultural enterprises. They have detrimental effects on forest soils and biota. These species are regarded as parthenogenetic organisms and the expectation is that most populations are clonal. We evaluated fourteen microsatellites loci to test the ploidy level for the two most abundant jumping worm species in Vermont, USA, A. agrestis and A. tokioensis.
Earthworms were collected from six different locations in Vermont. Including commercial nurseries, gardens and woodlands. Microsatellites analysis of jumping worms in commercial nurseries had the largest number of genotypes. High clonal reproduction was observed among different sites. However, there was also high genetic diversity, with 14 genotypes observed for A. tokioensis and 54 for A. agrestis, and with many singletons. These earthworms have different morphs with some being clearly parthenogenic while a few have a fully complement of sex organs. The proportion of male pore possessing jumping worms varies among years. While clonal reproduction suggests parthenogenetic reproduction, a great number of genotypes could be explained if there were multiple introductions from their native habitats or occasional sexual reproduction.
