Kind of a general rather than specific solution, but I would
guess that one could make a pretty good insecticide by
soaking velvet beans in water. (The water will contain L-Dopa,
which seems to be a fairly effective insect repellent/poison.)
http://belize1.com/BzLibrary/trust455.html
There is a lot of information there about velvet beans as
a (rather questionable) food, the bit about the L-Dopa and
insects was just a detail that happened to be mentioned.
The fact that it appears to be water soluble is interesting,
though (makes it cheap and easy to make a velvet bean
extract for spraying plants that have insect problems).
You would have to wash your fruit before eating it, but then
anyone that sprays their plants with anything should be
doing that.
There is a wild velvet bean that grows in the SE US, and
one can order an Amazonian version here (note the warning
on the toxic hairs; a "harvest with gloves and long sleeves"
item, most likely, and one may want to avoid growing it in
yards frequented by small children):
http://www.seedman.com/vine.htm