Controlling weevils must be harder than I knew

My goodness, I learn some unusual things by watching CNA.   I had no idea at all about the fumigation of rice being a thing, and especially that they have to keep re-fumigating it while it's in storage:

Singapore's largest rice stockpile contractor is using its own patented tech to defend against bugs. Rice sacks had to be fumigated every five weeks previously, but they can now be kept for up to a year. Singapore Storage & Warehouse houses its grains in these boxes that can keep oxygen levels inside low. This is crucial because insects like weevils need oxygen to survive. Currently, only half of the pallets in the company's rice storage warehouse are enclosed in these boxes. The firm plans to scale up and cover its entire inventory.

Here's the short video about it (and man, what a clean looking facility for rice storage):

Here's an Australia site that talks about using the poison gas phosphine to fumigate all grains.

Guess I had no idea that one of our basic foodstuffs needed so much exposure to poisons.    

Seems to be sort of thing that might attract rumours of danger to health from time to time.   And yes, it does -  here's a story from the Bangkok Post in 2013 about how rumours spread on the net about over-fumigated rice being unsafe to eat.   

Kind of makes me wonder why I haven't spotted a weevil in any foodstuff for many a year.  They are obviously pretty hard to control.