I heard a rumor that when doing some Columbia stall testing a test pilot
noticed that the stall was more benign when the leading edge was covered
with bugs.  Seems they caused the stall/separation to happen more gradually
(aka like a stall strips).

I also heard that the VG shapes help the flow re-attach after the stall.

Hence the tape with small plastic triangle shaped bugs. ;-)

Sounds like an Urban legend.  No confirmation on any of this.