A catalpa flower and its thrip

The best thing about hunting for the unknown is seeing the unexpected.  I was on a morning walk through the woods in my area scouting for flowers when suddenly I saw over a 100 flowers strewn on the path. The flowers were orchid-like, white with purple streaks with orange/yellow spots,  and were really pretty to behold. After some investigation I figured that they originated in the Catalpa tree some 50 feet above my head (Figure 1).

catalpa1Figure 1 (Click on figure for hi-res image)

A close inspection of the petal revealed that the purple streaks in the flower are distinct from the background white and they looked really great under the foldscope. They almost looked like runway lights for flying insects and are perhaps used to attract them to their pollen; which leaves me wondering if there is someway to read this color code like an insect.

 catalpaflo6  catalpaflo1
catalpa2 catalpaflo2
catalpaflo5 catalpa3

Figure 2 (Click on each pic for hi-res image)

 The pollen of these, about 50 microns in size  were the first of a kind I have seen and they appear to be in tetrads, like the atoms of carbon (Figure 2, bottom right). Wonder why they have this arrangement, perhaps they are a product of incomplete divisions?

As I was dusting the pollen onto the slide, I noticed a tiny arthropod running on it. There were quite a few actually, and in addition to the Catalpa sphinx moth (that solely uses this tree), these might be other residents of this plant with little publicity, and so I thought I’d foldscope one of them, about 1 mm in size, for identification.


Clearly this critter was a thrip with its characteristic fringed wings. Among the thrips, it seems to belong to the Terebrantia family as the last segment was not tube-like like the other family. Further it seems to belong to the thripidae subfamily. I couldnt go much beyond this, but in the future I will look for the features that are used to distinguish different families for a more serious endeavor. There is a wonderful resource on thrips for this. I also need to find a way of foldscoping these chaps without smashing them. I am beginning to wonder if, just like the pollen roster project, a database of flowers and their microarthropod associates should be made. Perhaps we can all join hands in some such effort to systematize the microarthropods and their biology? They are perfect for foldscoping.

3 Comments Add yours

  1. Manu Prakash says:

    @laksiyer: a detailed Foldscope catalog of Microarthropods is my dream. I strongly believe little insects don’t get the attention – and we don’t know what they do.

    Also; I love your idea of the runway lights. It’s incredible – I am wondering how it could be proven. We need to see like an insect and think like an insect.

    The silly putty trick will work great for micro arthropod – since you can easy change height. And when the time is right – you can press gentally to repress the motion.

    Finally, the hair like wings have a remarkable fluid dynamics insight hidden inside. As the scale gets smaller – a long cylinder has enough drag to generate lift. So many little cylinders is better than one wing of the same cross section. Think about it this way – if you stick your hand out of a car; would your fingers feel maximum force or your palm. Now if you reduce the size of your hand smaller and smaller – a transition should occur where fingers win 🙂


    1. laksiyer says:

      @Manu that is a very interesting lesson in fluid dynamics. I was wondering whether this chap would fly at all. They dont seem to instinctively fly, but when they jump off they might catch a wind easily. I am thinking of at least documenting a few associations of flowers and microarthropods over the next few weeks.

  2. Niramay Gogate says:

    @ Manu , I would like to contribute in making that foldscope catalogue for arthropods. How can I help you ?

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