I need to get the last task created on a particular item created in the list.
one option might be to navigate to respective workflow task list and search there (or query with a CAML) for the most recent task for a given item. the item the task relates to can be found in 'Related Content' field.
the other option might be to make a call to Workflow.asmx web service and its operation GetRunningWorkflowTasksForListItem
created in the list using SPServices and camel query?
how did you create it? doesn't it directly return ID of created task?