They really are a bane to farmers. We can thank them for a lot of chemicals used in our plant food production in taiwan. Ironically they are still farmed a lot for meat, so they are here to stay. I guess southern japan could have them?
We can collected bucket loads daily. Too tresome now we just give them astimp and move on. Calcium for the soil.
Google pic. Havent seen any that big, but pretty close. Last year saw a massive one about 90% that size around Daan park. So big you wonder if you might hurt yourself trying to kill them.