Ce l'ho fatta da sola! 
Posto il codice per chi potesse averne bisogno! 
codice:
Public Sub popolaTreeTipologie(ByVal miaTree As TreeView) Dim cmd As New MySqlCommand("SELECT * FROM tipologia ORDER BY parent_Tip ASC", cn)
Dim da As New MySqlDataAdapter(cmd)
Dim ds As New DataSet
da.Fill(ds, "tipologie")
da.Dispose()
Dim miaTab As DataTable = ds.Tables("tipologie")
ciclaTreeViewTipologie(miaTab, 0, miaTree)
End Sub
Private Sub ciclaTreeViewTipologie(ByVal miaTab As DataTable, ByVal idPadre As Integer, ByVal miaTree As TreeView, Optional nodoPadre As TreeNode = Nothing)
For Each riga As DataRow In miaTab.Select("parent_Tip=" & idPadre)
Dim newNodo As New TreeNode
If idPadre = 0 Then
newNodo = miaTree.Nodes.Add(riga("id_Tip"), riga("des_Tip"))
Else
newNodo = nodoPadre.Nodes.Add(riga("id_Tip"), riga("des_Tip"))
End If
ciclaTreeViewTipologie(miaTab, riga("id_Tip"), miaTree, newNodo)
Next
End Sub