Can we grow mealworms without grain feed?

I am planning to grow mealworms and would prefer them to be high in Omega 3s, so rather not to feed them grain or the least amount needed. Could I feed them just greens, hay, and vegetables? Do they absolutely need grains for their health?

Here's what I found:

"The darkling or mealworm beetle is a native species of Africa but has become naturalized in North America. They are often found in
cupboards, pantries, or wherever food is stored and are considered pests. In Africa the beetles and larvae eat decaying leaves, sticks,
grasses, and occasionally new plant growth. As general decomposers, they also eat dead insects, feces, and stored grains. Mealworms
live in areas surrounded by what they eat under rocks, and logs, in animal burrows and in stored grains. They clean up after plants and
animals, and therefore can be found anywhere where “leftovers” occur. "

https://www.wardsci.com/assetsvc/asset/en_US/id/16920388/contents

Thank you. So I don't have to feed them grain. But then I will need some sort of wood chip vedding or something like that?

Joy Oasis wrote:Thank you. So I don't have to feed them grain. But then I will need some sort of wood chip vedding or something like that?

They do prefer to have something to dig into in my experience. I'd just make sure whatever you give them as bedding is quite dry as I've had a few bursts of mold when my bedding gets wet.

Can i ask why you don't want to use grain?

Responsible grain production and consumption is not bad. Anyhow, I think you could simply use loose flax seed as their "substrate" which is high in omegas and they would also eat it. You could grind it to increase their consumption, that way you wouldn't have to use corn or wheat. I have used oats and cornmeal for a substrate for them but I haven't scaled beyond experimenting.

Joy Oasis wrote:Thank you. So I don't have to feed them grain. But then I will need some sort of wood chip bedding or something like that?

I would just use tree leaves and debris of that sort, or unfinished compost for them to hide in.

Lucas Green wrote:Can i ask why you don't want to use grain?

Because I prefer my worms grass or green fed. Higher nutrition. Grains have lots of calories, but they are high in phytic acid and nutrients inside are not very available. Occasional grain is okay, but as a main source of food -not so much. Neither for humans nor for animals. I actually can control my tooth from getting infection by removing all grains and fruit. I already do not eat sugar and seed oils for a year, but that alone is not enough.
Plus I rather feed them something I can gather or grow myself. I do not trust commercial foods grown by large corporations, eve organic. When organic oats were tested, from 15 samples, 6 contained significant amounts of roundup.

elle sagenev wrote:

They do prefer to have something to dig into in my experience. I'd just make sure whatever you give them as bedding is quite dry as I've had a few bursts of mold when my bedding gets wet.

I got some from Buy Nothing group on Facebook, and since they were fed oats, I put a think layer of oats and added guinea pig wood pellets (or roundish bobbles to be exact), and also gave them greens, and celery and carrots. They do not seem to be too interested in greens. I didn't get that much -maybe 30 worms and about 50 beetles, so can't try to eat them yet.

Joy Oasis wrote:

Lucas Green wrote:Can i ask why you don't want to use grain?

Because I prefer my worms grass or green fed. Higher nutrition. Grains have lots of calories, but they are high in phytic acid and nutrients inside are not very available. Occasional grain is okay, but as a main source of food -not so much. Neither for humans nor for animals. I actually can control my tooth from getting infection by removing all grains and fruit. I already do not eat sugar and seed oils for a year, but that alone is not enough.
Plus I rather feed them something I can gather or grow myself. I do not trust commercial foods grown by large corporations, eve organic. When organic oats were tested, from 15 samples, 6 contained significant amounts of roundup.

I'm not at all certain that phytic acid is bad for meal worms, or that the nutrients in grains aren't very available to meal worms. You seem to be presenting those things as fact, but I'm not sure that they are. I personally believe that grains are not good for humans to eat, and that fruits are, but regardless which of us is correct about that, I wouldn't say that is any evidence that those things are good or bad for meal worms.  I can tell you with no conjecture that i have been raising meal worms for years on dry dog food, chicken layer pellets, and alfalfa pellets ground in a blender. That food is also their bedding. The animals I raise that eat them are also healthy, thriving, and breeding well.  

As far as feeding organic, I would say that feeding any creature food without poison in it is best. If there are companies selling organic food that has "significant amounts of roundup", I don't understand how their organic certification wouldn't be pulled immediately.  There is certainly nothing wrong with growing your own food for your meal worms, but I would be concerned that raising them on grass may cause some nutrient deficiencies. I don't have any proof of that, but I would be conscious of that possibility.

We grew mealworms for a couple of years and always used buckwheat hulls for the substrate and fed them veggie scraps or rejects (potatoes, carrots, radishes, and zuke trimmings were their favorites). Never fed them any other grain.

I know on campus we had mast-producing trees and there were always darkling beetles scurrying about under them. I believe they may eat alfalfa pellets as well. I'll try and gather some different substrates to test next spring so far I have acorns or other nuts and alfalfa cubes or pellets on my list. They do eat carrots and various veggies, but in my experience it was at a much lower rate than grain bedding. keeping the bedding dry is the most important thing, since at least with the grain, you could get grain mites and yes, mold.

Grew mealworms for years.  Bran to eat and sliced potato for moisture.  They used to grow wild and fat in my grandfather's chicken shed on the floor under the chickens.

The problem with that is flax is too unstable due to the high polyunsaturated fat content, once ground the flax seeds won’t last longer than a couple weeks, and the oils will go rancid. It would be better to leave the seeds whole, although the beetles and worms would have more trouble eating it.

This would not only be detrimental to the health of the mealworms, (due to their passive respiration system they are very vulnerable to oxidative damage, so any extra from rancid oils may impair their antioxidant status and effect their growth and survival rate in theory.

Additionally, the ground flax would cause off flavors in the meat and eggs of any animals that you feed the mealworms to, since the mealworms would accumulate such high levels of PUFA from a rancid substrate.

This is well known in animal agriculture, especially in pork production, there is a hard limit on the amount of flax or fish oil you can add to an animals diet, before off flavors can be detected in its edible products. This is something that happens because of the low oxidative stability of PUFA, and omega 3 fats especially. This is also one of the reasons fish spoils so rapidly. Feeding high levels of vitamin E to livestock can reduce the off flavors in their meat and eggs, but not completely if very high omega 3 diets are fed.

Ive thought about this as well, and decided it would be better to dehydrate a very low fat, starchy vegetable with a good omega 3/6 ratio, and grind it into a four to use  as bedding, potatoes are a perfect option, and this could be combined with brewers yeast, and perhaps hay or dried weeds/green plants, and only a very small amount of freshly ground flax periodically, just enough to last one or to days at a time.

A second option is to make a high MUFA bedding using high oleic peanut flour, or some sort of high monounsaturated fat tree nut, like acorns, hazelnuts, macadamia, etc. acorns could be collected from the wild and cleaned, toasted, and turned into flour. Oleic acid is a healthy fat like omega 3, but far more stable.

I've grown mealworms on just garden weeds and vegetable scraps, works just fine. They are composters so they pretty much eat anything that is organic. I once threw a piece of rotten wood in the bin and they ate the whole thing within  a day. So you can make them grass fed if you want too, just gotta make sure you dont get mold.

I raise mealworms with a bran substrate, as they need something to burrow into. A sliver of carrot, apple, potato provides food and moisture. I made every mistake possible, put in too much veggies and the whole thing molded, killing the mealworms.  It smelled highly of ammonia due to the fermentation process and the dead, decomposing slimy mass of mealworms. Surprisingly a few survived and I had enough to start over.  Figured they would be tough and hardy and they do seem to be.   I raise them for my chickens.  

Joy Oasis wrote:I am planning to grow mealworms and would prefer them to be high in Omega 3s, so rather not to feed them grain or the least amount needed. Could I feed them just greens, hay, and vegetables? Do they absolutely need grains for their health?

Aren't these little buggers the ones that eat Styrofoam and produce compost?

I don’t have personal experience as a grower, but would paper waste be an adequate substrate? The particle size would have to be small, but does bedding just have to be a place to hide and stay dry?

The feed question is an interesting one. I think sesame is a good seed for oleic acids.

“The fatty acid composition in sesame seeds consists of abundant unsaturated fatty acids: oleic (35.9–42.3%) and linoleic (41.5–47.9%) acids from 80% of total fatty acids; less than 20% are saturated fatty acids, mainly palmitic (7.9–12%) and stearic acids (4.8–6.1%) [2].”

       https://www.mdpi.com/2073-4395/9/12/801

I think that sesame paste could be combined with veg waste and either dehydrated and mixed as a slurry for feeding, or frozen and thawed.


I think mushrooms, microgreens and mealworms are the perfect trio. Spent mushroom substrate and microgreen roots mixed with some sesame for healthy fatty acids make the systems link up elegantly.