Hmmmm.. Very unusual. Best way to handle this is to jus sit the toad in some water. Enough to submerge the beetle so that it drowns. After the beetle dies and is removed rub some Original Neosporin that does NOT contain Painkiller. Just plain Neosporin. This will prevent any infection in the bite. I believe this beetle is sucking the toads blood rather than eating him. Just submerge the beetle and remove it when drown.