The screenshot shows that no applications are started. There would be an application folder that you can expand to drill-down to application instances, etc.
You can start an application by connecting to it with any type of client. For example if you try to play a stream, even one that does not exist, in any playback client, Wowza will start the application if it exists. Then you will see it in JConsole.
You can also start an application in JConsole, just below were you are in VHost > Operations > startApplicationInstance: enter an app name in the first box, and an app instance name (or blank) in the 2nd box.
Richard