User-agent: *
Disallow: /wp-admin/
Allow: /wp-admin/admin-ajax.php

User-agent: Yandex
Disallow: /wp-admin/
Allow: /wp-admin/admin-ajax.php
Crawl-delay: 5

User-agent: bingbot
Disallow: /wp-admin/
Allow: /wp-admin/admin-ajax.php
Crawl-delay: 5

User-agent: dotbot
Disallow: /wp-admin/
Allow: /wp-admin/admin-ajax.php
Crawl-delay: 10