Live Mealworms eating plastic

This is probably the most bizarre and coolest organism I’ve ever seen under a foldscope. It’s a mealworm that eats Styrofoam (and other plastic) and degrades into biodegradable waste.

I’d read about these worms on the Stanford website, so when the researchers (Wei-min, Craig , Anja and Shandhan) who discovered them invited us to take a look at these worms using the foldscope, I jumped at the opportunity.

Before we jump into the videos, I have to share that the researchers were looking at these worms live under a microscope for the first time, and you can hear their excitement in their voices. The videos are also super long, but I hope you will enjoy the discovery journey we made together, and saw for the first time the sharp jaws of these worms, them munching in action, their negative reaction to light, and their gut movements.

So here’s a first video using an iPhone of the meal worms in a plastic container, enjoying their styrofoam snack. This should give you a sense of scale (upto 1cm long).

mealworms in styrofoam

We first took a small mealworm (early instar) to ensure we could see them under a foldscope. We mounted them by creating a ‘jail’ using paper slides and clear-tape.

The next image gives a comparison between the size difference between larvae. We first mounted the smaller one followed by the larger one (on right).

 Ok. So this is the first video. Keep a ear open for the excitement of the researchers who are seeing their organism live under a microscope for the first time.

Couple of points to observe from this first video:

  1. Sharp claws. Jim has really good ideas. I had to go back and re watch the video to really see the claws clearly. They are quite sharp. Why do they need such sharp claws?
  2. Squishy legs. Quite unusual.
  3. 3 pairs of legs and 1 pair of antennae. We mistakenly count antennae as legs.
  4. The discharge event- that’s how it ejects the digested plastic. Researchers can look closely at it to quantify the efficiency of plastic degradation. I understand that not all the styrofoam is digested- perhaps there are micro particles in the poop?
  5. Counting the thorax segments can help us identify the developmental stage.

mealworm in foldscope

mealworm antennae

mealworms jaws

mealworms pooping

Okay. So now we wanted to see its sharp jaws and mandibles that it uses to chew on plastic, so we flipped the slides over..

There is a big WHOA moment when we first catch sight of the jaws (4:40). Wow. What a moment.

mealworm jaws in foldscope beautiful

Now we decided to see if we could see in its gut and actually see plastic particles. The next video wasn’t successful but you can see gut movement

mealworm gut

In the next video, you actually see contractions of the gut due to transmission of light from the back-side. Keep an eye out for the neurons. These are sensitive to light and make the larvae phobic to light, which will become apparent in the next video. I imagine the neurons protect the larvae from excess light-exposure which can be harmful.

This is the last and final video. It is full of wonderful serendipitous moments. Watch it first and I’ll list out a few below for your reference. We actually have a piece of styrofoam in the slide to see if we could catch the worm in ‘action’. Watch to find out..

  1. We see the worm bite on the paper slides and start chewing.
  2. Do you see how it responds to agitation by light?
  3. Can you see how it’s using its leg and claws to hold on?

mealworm munching on plastic under a foldscope

Here’s an image of the worm and the holes it made on the slide.


Hope you enjoyed this post. Special thanks to Wei-min, Craig , Anja and Shandhan for sharing the worms. And Manu for providing the opportunity.

Keep exploring,


5 Comments Add yours

  1. laksiyer says:

    Wow Saad. A worm eating plastic!!!! What digests it in its gut? Must be some interesting microorganism. Wonder if it is a Pseudomonad? Would you know what organisms are suspected? Wonder how it would be if you gave it blue styrofoam (stained with methylene blue). This is nothing short of amazing.

    1. Saad Bhamla says:

      @laks. The microbiome of the mealworm is an ongoing research project at stanford and a team in China. No one knows yet. The interesting thing is that all stages of the insect – larvae (mealworm), pupa and the adult darkling beetle ( Tenebrio molitor) can digest plastic!! So it has a symbiotic relationship with bacteria in its guts at all stages. It’s baffling why it would evolve such a capability in the first place!

      I can give it some iodine coated styrofoam and observe them again. I have a jar filled with them on my desk. They are happily munching on styrofoam and make crunch noises if I listen carefully. I can try recording with my iPhone:)


  2. laksiyer says:

    @Saad Will definitely look at the genomes when they are out. It should be pretty interesting to figure out the biochemistry of degradation. Once that is known it will change the field, for one would know what free living bacteria to use in the future. Iodine will be toxic I suspect, but perhaps only in the long term. I love the crunch sound they make.

  3. This is the most amazing post I’ve ever seen in the foldscope community!!! I breed mealworms at home and been trying to feed them styrofoam as well but they haven’t yet chewed it. I think I’m not using the right type of styrofoam.

    The “WOW” moments in your video are simply amazing!!

  4. Saad Bhamla says:

    @Javier: I’m glad you enjoyed them. Interesting that you are breeding mealworms – can you share what species they are and where you collected them from?

    Perhaps it would be awesome to run a few control experiments and feed them polyethylene, polyvinyl chloride (PVC), PET, HDPE, LDPE etc. and see which one they prefer?
    Another interesting idea is to mix the food (bran + plastic) and see if you can keep them alive longer..

    Would love to read about your experiments.. Please share with the foldscope community – you can actually image their fecal matter to inspect what it contains and if it actually has plastic particles?


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