"I have a red wiggler worm farm and have been feeding my turtles them for 3-4 years now. The only info I can find regarding their toxicity is primarily to garter snakes.
Yes snakes and turtles are reptiles...they're cold blooded, lay eggs, have scales..but that doesn't make them the "same". Each species has things they can eat, love to eat, or can't eat. Just look at tortoises to get a good idea of how varied food can be between them. Some can eat fruits, to others fruits could kill them eventually.
I cannot locate any information regarding wigglers being toxic to turtles. Honestly I'm not worried about it. If my turtles have been eating them for 4 years and are thriving, with never a health issue...then my personal opinion is that they aren't bad for my turtles."