When using product import feature is the catalogue list automatically updated
From Online Business Wiki
Click on + to expand the category
When you use the bulk product import if the system finds a catalogue that it cannot find it will automatically create it. However if a catalogue already exists on the system but not in your import file then it will not be deleted. To remove catalogues use the web-based Admin interface.Go to eCommerce -> Catalogues -> select the catalogue you want to delete and click delete.

