LARQ used not to update the Lucene index as RDF statements were added/removed from a Jena Model.
LARQ is currently extending StatementListener  to keep a Lucene index in sync with a Jena Model, however this notification mechanism is not applicable in the case of SPARQL Update requests.
LARQ needs to update the Lucene index when a SPARQL Update request is received.
See also a relevant thread from jena-users mailing list:
- How to be notified of triples added/deleted to/from a Graph? – http://markmail.org/thread/l4ymug3ujoqifnty