Mystery of galls on leaves

Post about a mind-blowing observation I made 2day: while coming from office I saw strange nodules on a plant leaves. Out of curiosity I plucked one leaf with nodules n brought home. My guess was it must bel disease which is causing abnormal growth.

To check what these nodules made up of, I cut open one. I saw it was not some abnormal growth but a cavity like we see in avocado when seed is removed. And to my surprise there was a tiny insect sitting inside. I thought it must b dead but it moved.

I took the insect and put it under the Foldscope. It was beautiful animal, shot the following video. It was alive and I could see its body parts functioning.


Flipped the slide and took another video of its stomach and legs.


As there was no opening in the nodule I wasn’t sure how the insect must have gone inside. Is it possible that the insect forced plant to form the nodule around it. To probe further, I took a thin section of nodule along with the leaf as shown here

When observed the section of nodule n leaf under d Foldscope, I could c that the nodule was very much part of the leaf n it seems likely that the insect somehow forced the plant to make d nodule.


This is all speculation based on what I observed. I’ll be reading more about it and check how much what I think is correct.

Did some reading, starting with d article @kvijayraghavan sir shared. And suggestions given by @Abhadra7 @venadavenu @shyama13 @samalgorai this is what I found: the nodules are called galls. Various insects can induce gall formation.

After reading I found that I was correct in thinking that the insect forced d plant to form galls. D insect activates perturbations in d growth mechanism n alters d differentiation process in d host plant. Use it to their advantage.

Found a researcher named Anantanarayanan Raman from @CharlesSturtUni of Australia. He has studied the gall inducing insects in Indian subcontinent. I’m not sure if he is on twitter but his work is fascinating!
Here is the link-

And link to Manu’s post about similar observation


Finally identified the specific insect I had observed. It is Purposylla depresse. Crawford. Found a paper which describes it in detail. The paper is by K Veenakumari of NBAIR Bangalore.

2 Comments Add yours

  1. Manu Prakash says:

    Beautiful observation and documentation of the journey! Which is as fascinating as the observation. These are the movements we live for in science – the thrill of a ride. As we learn to teach and enable the tools to share this thrill first hand with students (so they are excited to go in their own roller coaster rides); education becomes yet another “fun” activity we all crave for.

    Keep up the beautiful work @edurafik!


  2. edurafi says:

    Thank you Manu. Agreed, these are the moments we live for in science!

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