Gunner Quinn
(Continued from Part 1.)
Results of Cornmeal in Sandwich Bags
As a side tangent, I wanted to know if weevils and their eggs in feed corn could survive being coarse ground into corn meal. Cornmeal is not ground as finely as wheat flour so I thought perhaps there was a small chance some eggs would survive. I put some weevily corn into the hopper of the grinder, added a bunch more weevils sifted out from some other corn, and ground it into meal.
After grinding, half of the meal was put into a mason jar with a sealed lid, the other half into a normal thin-walled sandwich bag. The meal in the mason jar would indicate if any eggs made it through the grinding process. The open sandwich bag sat on the counter for two months before it was zipped shut, hoping new pests of various sorts would enter. This would help establish the time larvae needed to chew through thin plastic.
No pests showed up in the mason jar during the six-month test, indicating weevils aren’t able to survive the grinding process. In the sandwich bag, after a few weeks I was unable to see any larvae but I did see particles of meal hanging from fine threads of web. The bag was then zipped closed. A few weeks later I finally saw larvae, and after a few months, many of the larvae had chewed their way out of the bag, one of which was halfway out when I saw it. The single threads of web had also turned into small mats of webbing in one end of the bag.
The contents of the infested sandwich bag were then transferred to a freezer bag to see if they could chew their way out through the thicker plastic, and how long it would take. That experiment is still ongoing.
Store-Bought Grains and Beans in Original Plastic-Bag Packaging
I couldn’t remember ever having seen weevils or other pests in unopened plastic bags of rice, popcorn, or beans. None of the store-bought beans or rice tested in this double freezer-bag system became infested with any kinds of pests.
Nor did any bags of rice I left on a shelf in their original packaging. A friend who worries about use-by dates gave me two small bags of rice last year which expired. They were date-stamoed 1/23/2024. Assuming the rice was at least a year old at that point, no pests have yet gotten into the bags after 2+ years. Both bags had air inside. I put one underwater and bubbles came out from the melt-sealed seams on each end, as well as through three small holes a few inches from the end seams. It’s likely to be just a matter of time before pests find and enter the bag.
A new 20 lb. bag of rice which sat in my pantry for four months before I got more food-storage buckets also remained pest-free. Twenty pounds of popcorn kernels in my cupboard have also remained pest-free over the past year, though just to be safe (being a founding member of Popcorn Addicts Anonymous), I did place those bags inside freezer bags after a pantry-moth infestation.
I also had in the pantry other two-quart jars with various beans and grains. All had been filled from the store packaging into the jars without oxygen absorbers or other “preservatives.” These included quinoa, garbanzos, split peas, and lentils. None of the jars had any indications of insects or frass. This lack of frass in all of these beans and grains in glass jars indicates that for the most part, these types of foods are clean when they come off the store shelf.
After doing some research on rice production, as part of the many steps of removing the natural oils in brown rice to create white rice, the grains go through a minimum of two washings. By the time the rice is packaged, the pests and their eggs have been removed. Therefore, any pests that infest rice must do so after the producer bags it.
The longer packaged food sits on pallets at the producer’s warehouse, food-distribution warehouses, grocery-store shelves, and our kitchen cabinets, the higher the risk will be that it will eventually become infested with weevils, pantry moths, flour beetles, mites, lice, or any of the other dozens of food-contamination organisms. All along the supply chain, holes can get punched in the packaging allowing pests to enter. The larger the bags are which store-bought food is packaged in, the heavier they’ll be and more subject to dropping and rough handling, thus increasing the possibility they’ll get pest-entry holes during their journey to our pantries. Therefore, to decrease the chances of freezer-bag stored food becoming contaminated, it’s a good idea to put from the original packaging into the freezer bags as soon as possible after buying it. Small one- and two- pound bags can be placed directly into a freezer bag. With mylar bags and standard food-storage buckets using oxygen sensors, or with any freeze-treated food, this timing isn’t as critical.
Many pests have a flying-adult stage which allows them to move from infested areas to locate new food sources elsewhere. Once they find a new food supply, they exploit it via holes in plastic food bags, seams in paper packaging such as flour and corn meal, seams in cardboard pasta packaging, and most of them can chew through paper, plastic, cardboard, and foil packets. Some of these pests can infest so quickly, seemingly out of nowhere, it makes me wonder if spontaneous generation isn’t a true principle after all. If our pantry shelves are already infested with pests, which we may or may not even be aware of (been there, done that), the more quickly some of our JIT food can become contaminated.
For any foods which are left in the open, or in containers we mistakenly thought were closed, pest infestations will almost certainly occur. A lot of damage can occur by the time we discover the infestations. As an example, I had four inches of rice left in the bottom of a five-gallon bucket which I thought was sealed. It wasn’t quite closed and I sifted out a little over half a cup of frass.
I now use sticky traps in my cupboards as an early-warning system. These are generally advertised as fly traps. I use the clear, non-toxic type which aren’t noticeable when applied to the inside of cabinet doors. They cost 75 cents each in a 12-pack and each one can be cut into thirds to get more mileage out of them. I highly recommend using these types of early pest indicators. Be aware that dry pet foods are another common source of pests so I have a sticky trap where I store cat food.
Results in the Gasketed Tote
The 3-gallon tote I used for part of the experiment had a gasketed lid. I tossed some loose weevil-infested feed corn and pantry-moth larvae into the tote after it was filled with freezer bags of food to speed up the process of seeing if they’d chew through the freezer bags. By the end of the experiment, inside the tote there were still a few adult weevils, an adult pantry moth, loose larvae, likely eggs, and cocoons in the tote. None of the larvae had chewed their way into the freezer bags and none of the weevils inside the bags of corn had chewed their way out.
On the underside of the tote lid however, there were five cocoons and 22 larvae, no doubt ready to form their own cocoons. Surprisingly, the larvae had managed to chew 19 holes, some fairly large, in the gasket material. They hadn’t yet chewed their way clear through to the outside. Based on the observation that newly-hatched larvae can chew hard corn kernels, and the thickness of the gasket material, I think it was just a matter of time before they’d be able to chew their way through. The gasket material is 8 mm (5/16th of an inch) thick. With that thickness, and the rim of the tote only depressing the gasket 2 mm, it was probably just a matter of time before they could burrow underneath the other 6 mm of gasket material. What gets out can also get in so the possibility exists that pests from the outside could eventually get into the tote, something to keep in mind when storing food.
(To be concluded tomorrow, in Part 3.)
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