Grouping Tile Packages in Flex TOC Layer List

I have an orthophoto base map I have split up into 20 tile packages (1-2GB each), and uploaded ArcGIS Online individually. Is there a way to group these in the legend and layer list so that they can be treated as one layer?

Orthophotos
Tilepack01
Tilepack02
Tilepack03
Tilepack04
...