I wouldn't be too worried about the splenda, I don"t know about the popcorn or baking powder. I have found webs and larva in the folds of packages and rims of containers. A few Bay leaves tossed on the shelves help repel them. Good luck with that disheartening job.

"I have heard that sometimes larva and eggs come inside packaged food (is that true?)"

Yes it is.

"Do I need to refrigerator new unopened boxes "

Freezer is better. A few days in the freezer kills any larvae or eggs.

Think about investing in a vacuum sealer for any long term storage.

Dave

Thank you. Unfortunately I lost my big freezer in the flood, and it would not be appropriate in this tiny apt anyway. So as room develops in the freezer I am going to cycle food into it for a few days. Before and after, those items will be in the refrigerator. Except for the unopened bags of Splenda, they just have to stay in the pantry.

And the pantry will be the place I store metal store bought cans.

I use glass jars for long-term storage in my pantry. It worked for my Mom and it works for me. And, yes, the eggs/larvae can already be in the food.

I also use glass jars for pantry storage, I have a large collection of very old canning jars and use those as I am not comfortable putting a 100 year old jar in the pressure canner!

I bought traps from Gardens Alive and they worked great. I caught so many moths it was disgusting, and I continue to use one every now and then just for "testing" to make sure the problem doesn't reoccur.

https://www.gardensalive.com/product/cupboard-moth-trap-1

Of course I had to throw away the flour and cereal, clean my entire pantry, stash things in the freezer. I didn't want to spray insecticides in my pantry, so I liberally scattered bay leaves and used these traps after the "clean and discard" portion of the program was completed. I don't know if the bay leaves actually work, but I was told by several people that they would help and I figured they couldn't hurt. I was given a large 2 quart jar full of dried leaves by a friend, so I used them liberally.

Good luck!

Annie

Annie: I also use those moth traps and am greatly surprised by the number caught in every one.