Here are two ways to remove replytocom urls from Google search and to stop Googlebot from crawling this type of urls.
First Way- By Using Google Web Master Tools
It is the best way to prevent Googlebot from crawling and indexing duplicate content in the form of replytocom urls. In Google Webmaster tools we have to set just a url parameter for it.
- Go to your Google Webmaster site control panel
- Locate the option Site Configuration > url parameters
- Here you will see different pre-added parameters
- Locate and edit the “replytocom” parameter and edit it ( if it does not exist then you have to add new one
You have to set following options now;
Does this parameter change page content seen by user? = Yes changes, reorders or narrows page content
How does this parameter affects page content? = Paginates
Which URLs with this parameter should Googlebot crawl = No URLs
Second Way- Replytocom Redirector WordPress plugin
This plugin redirect Googlebot and other bots to the original URL and thus it saves your site from being a victim of duplicate content.
Plugin page- http://wordpress.org/extend/plugins/replytocom-redirector/