I have heard of hydrated lime (or more commonly baking soda) being used
as a control for fungus. I can't say that I have ever heard of it as a
control for insects. I would not recommend using lime for either purpose
as it can burn the leaves.
snips

Hi,
As a chemist you're a better writer ;0) and I hope you're not into baking.
baking soda is sodium bicarbonate (NaHCO3)
hydrated lime is calcium hydroxide Ca (OH)

You are correct. I should have been more clear. What I meant was that
hydrated lime dissolved in water has been used as a control for fungus.
Baking soda is more often used for this same purpose because it is less
alkaline and hence not as phytotoxic. BTW, I gave up baking years ago