I was a bit suspicious of the claim, but found evidence that this might actually be the case. Here's a page focused on research related to non-native earthworms

I was a bit suspicious of the claim, but found evidence that this might actually be the case. Here's a page focused on research related to non-native earthworms in North America that seems like a good start: https://www.nyisri.org/2016/09/underground-invaders-impacts-implications-non-native-earthworms-north-america/ https://www.nyisri.org/2016/09/underground-invaders-impacts-...