Tuesday, December 26, 2017

UPDATE: Rhinoceros Beetle Babies


A few months ago, I wrote about how we accidentally became rhinoceros beetle breeders.

Well, today, I’m posting an update.

We were given 5 mature adults, and they’ve since passed on, but now we’re taking care of their offspring.

We began with twenty-some-odd eggs, but only 12 grubs have made it.

After reading up on rhinoceros beetle breeding, he have become aware of some interesting, yet disconcerting facts.

Firstly, we were shocked to find out that rhinoceros beetle grubs are voracious eaters.

They’ll eat everything they can find, even their own fellow siblings.

This shouldn’t be too surprising, but all that eating also results in regular pooping, which is why good rhinoceros beetle breeders must sift through the dirt the grubs are growing in monthly for poo.


 The soil in which the grubs live must be sifted for poo every month or so.

A soil poo-sift is a good time to check up on the health of the grubs, and see how many are still around, and beginner breeders are warned not to be too surprised if there are less grubs than they began with; the grubs will eat each other and this is simply a fact of life.

To do a soil-poo sift, the tanks must be emptied out, preferably by turning them upside-down and emptying their contents onto two or three spread sheets of newspaper; the newspaper makes for easy clean-up afterward.

 The contents of one of the tanks dumped out.
How many rhinoceros beetle grubs can you see?

This in itself can be a hair-raising experience if you’re not used to it; the grubs like to hang out at the bottom of the tank, so when you turnover the tank to empty it out, the grubs will roll down from the hill you just made, wriggling and writhing about.

You’ve got to pick these little crawlers up with your bare hands and put them somewhere so they don’t hurt themselves or get away.

Then, you use a sifter to sift through the soil for poo bits or any grubs.

The poo are these interesting, black, square bits that resemble black Chiclets.

 Rhinoceros beetle grub poo up close.

They aren’t mushy or smelly, just hard and odorless.

You might be wondering why I'm focusing on poo right now.

Well, for one, a poo-sift/status check on my beetle grub babies is what this post is all about.

Second, I thought maybe my Japanese readers might be interested, seeing as Japan does seem to have this fascination with poo, as I've already mentioned in another post.

Anyway, moving on...

After sifting through the entire mound of soil, you’ve got to put the soil back in the tanks, and add more breeding soil; over a third of what you remove from the tanks is poo, and the dirt must be replenished.

You can buy bags of special breeding soil that has food and nutrients in it for the grubs to eat at most Japanese hardware stores.

 Special dirt for rhinoceros and stag beetles, clearly labeled.

After replacing the dirt in the tanks, and adding more breeding soil, you can put the grubs back in, and they’ll automatically start to dig themselves back in, and you can leave them in the tank until the next change; the Japanese interwebs say to do a soil poo-sift every month or so.

 My babies beginning to dig into their fresh new dirt.

Other pieces of advice are to make sure the soil is nice and moist; we do this by checking the top soil with our fingers, and spraying the soil with water, using a spray-bottle you can get at a 100 yen shop.

The interwebs say that they won’t get ready to change into rhinoceros beetles until late spring, when the summer approaches, so it’s going to be soil poo sift for the next few months.

 Both tanks sifted and replenished with poo.
I mean, I mean DIRT. Replenished with dirt.

Raising rhinoceros beetle grubs is interesting. I can’t wait until the grubs cocoon and hatch into full-fledged beetles. Will my beetles survive the winter? Time will tell.

Until the next poo-sift!



Related Post: 
Accidentally Rhinoceros Beetle Breeders

Japanese Toilets