Mealworm farming

[NHsolarguy]

Good info! You have got to be an engineer... I was kind of expecting a graph or two after reading your description...

If you've got a sunny window, put them there and put some dark stone (or paint some bricks black) below the box. They will absorb heat during the day, and release it during the night. This may bring the temperature up by 10 degrees or so, putting your mealies into the sweet spot for growth. This is "passive solar" heating, on a small scale.

 

[Chaneys Ranch]

CAUTION: LONG POST TO FOLLOW (got carried away haha)... nothing really new, but just putting things in perspective

I was just reading a quick study of temperature affects on darkling beetles. No species was given since this was not the actual scientific study, but was using graphs from one. The first thing I noticed is that the temperature of the litter is more important than the air. This makes sense since that is where they live. So using a reptile heater or something like some people here are doing seems to be a great idea. The second thing I noticed is that temperatures just below 70F are quite different from those around 80. The difference between 80 and 90 and 100F were not as drastic even though there were definite differences. At 68F, the life cycle is much longer and as a result the survival rate is much lower. Like I said, the species was not given and I am pretty sure this is not the ones we grow, but the logic still stands. When the litter is cooler, it takes longer for the eggs to hatch which increases the likely hood that the egg won't hatch at all. But that is just the start. The cooler temperatures also increase the time in the larval stage (mealworm stage). This has a large impact on survival rate.

Besides temperature, one thing that sticks in my mind is the difference the starting colony number makes. I knew that it made a difference, but never really calculated it. In my mind I am thinking in terms of increasing the number 10 fold over the life of the beetle. Like I said, I never put numbers to it. But even with my original estimate, starting with 50 mealworms yields 500 vs starting with 1000 mealworms yielding 10,000. Boy, was I in the wrong mindset. Now that I saw some real numbers applied in this article, not only were my numbers off, but this is really a logarithmic difference. The article says that on average, you can expect 5 eggs per day from a female in the higher temperatures (over 95F). If you start with enough mealworms to yield 100 beetles after the mortality rate, let's say 50 are female. That means that 250 eggs are laid a day. After 30 days, that is 7500 eggs. After 60 days, that is 15,000 eggs. After 90 days that is 22,500 eggs. Now let's look at the same numbers if you had enough to end up with 200 female beetles (so 400 beetles in our example). 1 day = 1000 eggs. 30 Days = 30,000 eggs. 60 days = 60,000 eggs. 90 days = 90,000 eggs. This is just egg production. You would then have to factor in the mortality rate of the eggs and the larvae. But you would also have to factor in any larvae becoming a beetle and laying their own eggs. But I'lll stop here before I make this even longer.

So now I am wondering the best way to get my temperatures up. I would say anything over 80F would be ideal. Right now they are at around 70 (I haven't checked for a bit). I don't really want to use a space heater and the reptile pads that attach to the outside of the cage give a large range of possible increase for the product (between 2 and 8 degrees F). Not worth it for 2 degrees, but maybe for 8. However I imagine there are ones out there that might be better. I also can't wait for Spring... or Summer

yep.. thats why i keep my beetles together (only move beetles) and everyone is on heating pads

Nice job putting it all together!

 

[Chaneys Ranch]

Good info! You have got to be an engineer... I was kind of expecting a graph or two after reading your description...

If you've got a sunny window, put them there and put some dark stone (or paint some bricks black) below the box. They will absorb heat during the day, and release it during the night. This may bring the temperature up by 10 degrees or so, putting your mealies into the sweet spot for growth. This is "passive solar" heating, on a small scale.

good point also.

 

[Mavrk]

Excellent points about the importance of the starting size of the colony Mavrk! There is another reason initial population size is important: the number of eggs a female will lay (fecundity) is directly proportional to the number of mates she has. Males transfer substances during mating (beyond sperm) that facilitate egg production. Indeed, females produce a pheromone to attract as many mates as possible to facilitate this benefit. With greater population densities females will have greater opportunities for interaction with males.

Also, I like to think about temperature and mealworm development as a candle. The brighter the candle burns, the shorter it's duration. The dimmer it burns the longer it burns, but with greater risk of being snuffed out. Perhaps it's an oversimplification, but for our purposes it seems apt. The greater the temperatures, the shorter the lifespan. There is a "sweet spot", somewhere in the 80's where the trade-off between speed of development and shortened lifespan will produce the greatest number of offspring.

I hadn't thought about fecundity. Glad you piped in. I like the candle analogy. I think the "sweet spot" might depend on what your goals are. If I had to choose a temperature for myself, I would say it hovers around the 90 degree F mark (maybe 88 or so). This is where survivability is at it highest while development speed is fast enough. For some, development speed might be more important where the slight increase in speed is offset by a slight decrease in survival rate. After all, over time that speed could very well more than make up for the deaths. If I were looking to do this commercially, I would aim for temperatures of around 95 degrees F.

One question I see a lot on here is about time. The standard answer is that it depends on different variables (temp, humidity, food, space, etc). The thing that I don't see often enough is giving the ideals so people can have higher production. I have seen some good posts on humidity. Food is covered a lot. Space is covered a lot too with people having multiple bins, etc. But when it comes to temperature, usually the posts relate to what is too hot or too cold. So it would be interesting to read other people's experience in how specific temperatures (or any other variable) have made an impact on their colonies.

I purposely didn't give numbers on my last post for development vs survivability because I believe that to be a different species of darkling beetle. But for the sake of an example I will give some estimates (only graphs to go by, not the data behind them). I would say the biggest impact on beetle population is the larval development speed/survivability. The numbers for overall egg to beetle speed/survivability follow that pretty closely. Here are some estimates of Egg to Adult beetle times and % survivability as a property of Temperature (degrees F).

68F = 150 days with 30% surviving to adulthood
78F = 55 days with 58% surviving to adulthood
88F = 33 days with 70% surviving to adulthood
95F = 28 days with 67% surviving to adulthood
100.4F = 30 days with 62% surviving to adulthood

On a side note... I wanted to thank Gallo del Cielo for his article on the single aquarium setup. I wouldn't have gotten into this if it was more complicated than that.

 

[Mavrk]

Good info! You have got to be an engineer... I was kind of expecting a graph or two after reading your description...

If you've got a sunny window, put them there and put some dark stone (or paint some bricks black) below the box. They will absorb heat during the day, and release it during the night. This may bring the temperature up by 10 degrees or so, putting your mealies into the sweet spot for growth. This is "passive solar" heating, on a small scale.

Actually I was a scientist in a former life (a.k.a. college). I spared you the graphs though.

 

[Mavrk]

Just wanted to report that I found some of the actual scientific studies on the species. Most of the translation leaves much to be desired, but the one thing that is clear is that the ideal temperature for raising mealworms is between 30 and 35 degrees Celsius. This translates to between 86 and 95 degrees Fahrenheit. This supports the article I read and reported on above.

 

[Chaneys Ranch]

Just wanted to report that I found some of the actual scientific studies on the species. Most of the translation leaves much to be desired, but the one thing that is clear is that the ideal temperature for raising mealworms is between 30 and 35 degrees Celsius. This translates to between 86 and 95 degrees Fahrenheit. This supports the article I read and reported on above.

The reptile heating pads are typically around 90 degrees. they can be clued to the bottom of the tank/tote/container. They are cheap and work great! Seedling mats are good too from what i have been told, but mine are reptile mats.

 

[LaBella]

Yay... Another victim falls prey to this thread. WELCOME!

Just wait until you have nothing but beetles and are waiting for signs of babies. That is when your patience is tested. Of course, once this happens I would say that your patience is tested again as you wait for the tiny "worms" to get bigger and useable. I think I will start my 2nd container tomorrow

ETA: As far as parakeets, I would say it depends on the type of parakeet. Easy enough to try though.

The fun thing for me is I have already been down that road, raising mealies and supers for my box turtle.

This thread was NOT a good thing for me.. It's like an alcoholic going to a bar.. I was just LOOKING for an excuse, you know, lol. So more like another victim falls prey AGAIN, like the Godfather, "Just when I thought I was out... they pull me back in."

Also, with regards to heating.. I used flex watt heating tape for my betta tanks, Best thing I ever used to keep the beanie containers at a stable temp. As I phased out of bettas, I started using the flex watt tanks for the mealies. I didn't really need to, since my in house temps were about 78-79, but they loved it a few degrees warmer than I did.

 

[Chaneys Ranch]

Quote:
Hahaha too funny

 

[Tikkajazz94]

WOW!!! very good points!!!