I have just found a very informative source for biological control of pests.
He can send you a manual/catalogue on which bugs eat what Arabidopsis pests.
For now, lady bugs eat aphids, a mix of Hypoaestus miles and Aureua Insidiousus
eat thrips and also eat fungus and fungus gnats. Yum.
The Green Spot
93 Preist Rd.
Barrington, NH 03825
Cambridge, MA 02139
kearns at mit.edu