You have to apply this following code into this file -> JoomlaFolder/components/com_easyblog/views/login/view.html.php

[gist type="php"]
$this->doc->setMetadata('robots', 'noindex,follow');
[/gist]

You can refer on my attached screenshot below.

After you applied, you have to wait for Google to reindex on your webpage again then only affected those search page.

Or you can submit your sitemap over to Google, so Google should index your webpage faster.

Reference link : https://support.wix.com/en/article/submitting-your-sitemap-directly-to-google

Thanks Arlex

I have added the no follow tag.

Better still can this front end login be disabled? We always login the backend to add posts so not really needed.

You're welcome.

Hm unfortunately that was not possible to disable this login page.