Hello...If the meal worms mate with the fruit flies you will end up having flying meal worms That is bad. They are known to mate with tomatos and you end up with watermellons. There is no telling where things will end if it reaches that stage...Franklin

If the off-spring of the flying meal worms mate with tomatoes, can he get flying watermelons? Because that would be cool...

(I'm actually curious about the answer to this as well.)

I'll try it and see what happens. I'll be coming into possesion of a praying mantis soon, and while the fruit flies will be ok as food while it's in the nymph stage, it'll need something bigger when it reaches maturity. Mealworms (or the beetles they turn into) would make pretty good meals for them. I'll order a small tub, chuck it in, and hope for the best.

I found some mealworms in my compost a few weeks back...I picked some out and put them on my bird feeder as a special treat...next week I went back and they were all dead...the heat killed them for sure

I have a related question: with a compost tumbler, which one day I opened, and it was normal (full of bugs) and the next day was FULL of mealworms! They don't really bother me, I just wonder A) are they a good thing and B) will they survive and C) if they die, is it going to be a nasty stinking mess? Should I leave it open and let the birds enjoy themselves? If I leave them in, will I end up with a plague of beetles in the garden? sorry I am not more informed, I am just starting out in the composting process...

I added meal worms to my compost today (got a free sample from wild birds unlimited)they didn't even burrow and were eaten shortly after. if only the birds would dispose of them where they found them...

In reality any bugs you can see are an indication of a problem with the compost and usually that means the compost is too wet since these insect larva need a fairly moist environment to hatch and live in until they pupate into the adults of what ever they are. Many people used to think that the larva of the Black Soldier Fly was good because they misunderstood that it was the Black Soldier Beetle that was the insect pest predator. All the adult Black Soldier Flies do is mate and die, the adult flies do not even eat.
So if you have wiggly thingys in your compost pile that you can see that is usually an idication your compost is too wet and needs to be dried out.

Bugs are NOT necessarily a problem with compost.

Check out this information on compost critters from California Integrated Waste Management Board.

They lists snails, slugs, millipedes, sow bugs, pills bugs, mites, earthworms, flatworms, winged beetles, spring tails, centipedes, rove beetles, ants, spiders and earwigs as common compost critters that all function to help create compost.

Though I probably wouldn't ADD mealworms to my compost because I thought they would speed up the compost process. If had some meal worm worms that I needed to dispose of, I would toss them in the compost assuming they would die and be consumed by other things in the pile.

Here is a link that might be useful: Compost Pile Critters

I bought a bag of mealworm castings and opened it up when I got home and found it crawling with live Darkling Beetles, which are the adult form of mealworms. I want to know if I use the castings as a soil amendment or organic fertilizer will I be introducing a plant eating pest into my garden? I looked up Darkling Beetle on Wikopedia and it says they will eat live or decaying vegetation. I don't need another insect eating my vegetables and fruit. What about the mealworms themselves, how dangerous are they to put in a garden. They are fed carrots among other things, so I assume they will also be a pest if introduced into the garden.
In the meantime I put the bag into a black garbage can and set it out in the sun in hopes that the heat will kill any Beetles, larva, or eggs in the mealworm castings.
Should I try to get my money back, and if I can't should I throw these mealworm casting away, but not in my garden?

Most all insect larva that you can see need an environment that is too moist for proper composting, ie. the only time you would see them is when conditions are better for anaerobic digestion then for aerobic digestion.