Reason:
Deleting a monitor from the monitor group will only remove its association with the monitor group. This will not stop its monitoring.
Solution:
1. To delete the monitor also, click 'Monitors' tab, select the monitor and click Delete. This will remove the monitor completely.
2. If you wish to delete a monitor group and monitor's associated in them please follow the below steps.
* Goto AppManager's Monitor Group View.
* Select the Monitor Group on which you wish to do the operation.
* In the top left hand side of the box, In the drop down list select delete option. 
* In the following pop-up window select the below option and delete
