Based on an archetype i created a java ee app. There is an included arquillian test that runs fine. it just calls a method on a @Stateless bean that persists an pre-made ent
In order to have transaction support in Arquillian tests you will need to bring in extension which enables this feature. In your case jta dependency should do the job.
org.jboss.arquillian.extension
arquillian-transaction-jta
test
In addition, if you are using JBoss, you will need to provide its JNDI for UserTranscation, so put following section in your arquillian.xml:
java:jboss/UserTransaction
This way you can use @Transactional which comes from this extension's API.