Hi, deleting the intrusions manually is not required.
HMWP IDS detects malicious requests coming to your site and notify you about it. But all these requests might not be harmful and you need not worry as HMWP IDS will take care of this and will block the malicious requests if Impact level is more than 20 (default value specified in HMWP IDS). You can stop receiving emails regarding this by setting “Notification Threshold” option to 0 in IDS Firewall tab.
Note: If in case, valid request is also listed as intrusion then hover over that request name and click on Exclude link to add it to exception list.
As I explained above, you should not worry about it and need not delete them manually. These are the list of requests detected/blocked by HMWP that it found to be malicious. But be noted that all the listed items are not blocked, only the requests that have impact value more than “block threshold” value will be blocked.