How to indicate in C# that application is running on Parallels or VmWare on Mac

Hi I am using the following code to indicate if code is executed on virtual machine.

using (var searcher = new ManagementObjectSearcher("Select * from Win32_ComputerSystem"))
{
    using (var items = searcher.Get())
    {
        foreach (var item in items)
        {
            string manufacturer = item["Manufacturer"].ToString().ToLower();
            Console.WriteLine("Manufacturer: " + manufacturer);
            Console.WriteLine("Model: " + item["Model"].ToString());
            if ((manufacturer == "microsoft corporation" && item["Model"].ToString().ToUpperInvariant().Contains("VIRTUAL"))
                || manufacturer.Contains("vmware")
                || item["Model"].ToString() == "VirtualBox")
            {
                Console.WriteLine("Manufacturer: " + manufacturer);
                Console.WriteLine("Model: " + item["Model"].ToString());
            }
        }
    }
}
Console.Read();

What ManagementObjectSearcher parameter could be use to indicate is it Parallels on a Mac running XP SP2 or VmWare on a Mac running Windows 7