Thank you for pointing us to Libelium's site. Typically devices that are recently Thingworx Ready can be found on marketplace.thingworx.com. For the Meshlium, you can update the EMS to the latest version, then to get the data out of the waspmotes to the platform, you may consider writing a lua script resource that reads the MYSQL database on the Meshlium.
Since the waspmotes connected to the Meshlium are sending data over Xbee (etc) the Meshlium itself has a java parser that reads in the zigbee frames and pushes the data into a table on the Meshlium, its that table you want to read from to push data to the Thingworx platform.
Hopefully this at least provides you with a direction!