That is the PreDestroy in the context of a MessageDriven bean.
On p.17 (and in the graph on p.21) you will find the following summary for Session Beans:
2.1.9 Predestroy not called 1. A crash of the EJB container.
2. A system exception thrown from the instance’s method to the container.
3. A timeout of client inactivity while the instance is in the passive state. (Stateful SB only)