Do I need to make my web service secure?

Question

If I were to host a web service on the same machine as my web site, and pass sensitive information to it, do I need to call it using https?

For example, I would reference it using localhost, so won't this information be secure as it's not being transmitted across an insecure channel?

EDIT: I should mention that this web service would not be accessible from the outside world.

Thanks

Answer 1

Yes, if you service is accessed using as http://localhost, then no information will be transmitted across the network, so https is unnecessary.