That is expected behavior and not limited to IPC events, tasks are created typically by the workflow where one uses a client event and these are displayed on the worklist. And IPC event starts another workflow and therefor will not have any associated task listed on the worklist. The same counts for all the other events that is not of type “client event”. 

Let me know if you have further questions.

The process ID typically available from the Object browser under the workflow context node.

Is there a workaround?

or shall i add a datafield for the ipc process called parent in order to identify it's paret from the application.

You can pass the Parent workflow instance ID through to the child as part of the IPC configuration. Coming back to the original question, having the parent process ID is still not going to help you get it show up on the worklist.