Looking around on the internet, the claim is actually that the rhinoceros beetle can carry 850 times its own weight, not just 100 times its own weight. The type of rhinoceros beetle in question is the "Hercules beetle" (Dynastes hercules)
Adults of some species can lift objects 850 times their weight! That
would be equivalent to a human lifting 9 fully grown male elephants!
One such claim
Compared to an elephant, the rhinoceros beetle looks minuscule. But
ounce for ounce, this insect is considered the world's strongest
creature Rhinoceros beetles, which get their name from the hornlike
structure on a male's head, are capable of carrying up to 850 times
their own body weight. A human with this relative strength would be
able to lift some 65 tons (59 metric tons).
Another such claim
This sounds really crazy, what is it the beetles actually does, and how heavy things is it they have lifted?
Male Hercules beetles can be up to 17cm long, and weigh up to 120g.
The species exhibits ‘sexual dimorphism’, which means that females and
males are very different in appearance. For a long time, scientists
thought that they were actually separate species; only the males have
horns (which make up to half of their body length). These horns are
used to fight other males, burrow into wood and move obstacles (like
sticks, rocks and small logs) out of its way.
Weight of the beetle
The beetle seems to push around rocks, sticks and logs using its large horns.
The beetle's weight is in other words 120g, and can lift things 850 times its own weight.
0.12kg * 850 = 102 kg. The beetle have apparently been shown to lift things weighting 102 kilos. This sounds pretty fantastic. How have those tests been done? Did the beetle really just grab a 102 kilo rock, and move it about?
Youtube link
In the video, it shows the tests done by scientists in University of California, Berkeley, CA. And the beetle was shown to carry 100 times its own weight ON ITS BACK. The video says they tested that.
Details about the tests can be found in the paper "INEXPENSIVE LOAD CARRYING BY RHINOCEROS BEETLES" from 1995, from Department of Integrative Biology, University of California, Berkeley, CA.
There they tested how much the beetles energy consumption changed with carrying 30 times its body weight. And in the paper it's depicted the tests shown in the youtube video as well. The beetle could move pretty much unhindered with 30 times its weight. The paper didn't say anything about 100 times it's weight, but it wasn't completely related to the topic.
Where the number 850 times its weight comes from that is the question.
Females of the species will dig a tunnel into a pile of dung and males
will enter the tunnel looking to mate. If a male encounters another
male in the tunnel they will battle each other, each trying to remove
the other. The scientists tested the beetle's ability to resist rivals
by measuring how much weight was needed to pull a male beetle out of
his hole. That's how they know that it would take 1,141 other beetles
to pull a determined male dung beetle out of 'love tunnel'.
Idea to where that idea might come from
Probably a similar test was done to the Hercules beetle. That means the 850 times number is not for amount it carries on its back, but how strong it is.
Yes the beetle can carry 100 times its weight, on its back