No, it is not possible to select items on a right-click without extra form code.

The following code sample demonstrates how to use the SelectedItems collection to programmatically select items, in this case in response to the pressing of the right mouse button:

/// <summary>
/// Handles the UltraListView's MouseDown event.
/// </summary>
private void UltraListView_MouseDown(object sender, MouseEventArgs e)
{
    if ( e.Button == MouseButtons.Right )
    {
        UltraListView listView = sender as UltraListView;

        if ( listView != null )
        {
            UltraListViewItem itemAtPoint = listView.ItemFromPoint( e.Location );
            if ( itemAtPoint != null )
            {
                bool controlKeyDown = (Control.ModifierKeys & Keys.Control) == Keys.Control;
                listView.SelectedItems.Add( itemAtPoint, controlKeyDown == false );
            }
        }
    }
}