Whirligig Beetle

Whirligig Beetle

Came across this big group of individuals swimming around in a small stream in Coorg. They could easily have been mistaken for a school of fish and I did too. However, they seemed to be swimming on the water’s surface, with the upper half of their bodies outside, unlike most fish. Looking closely, realized that they weren’t fish at all, but a completely different kind of creatures. They were insects, more specifically, beetles.

Whirligig beetles

These beetles are more popularly known as the Whirligig beetles. They get this name from the way they whirl around rapidly in circles when threatened, as if caught in a whirlpool.

Whirligig beetles belong to the ‘Gyrinidae’ family of water beetles. They do have wings like most other beetles and are very much capable of flying. However, these are preferential water denizens. Having a nicely lubricated outer layer, hind legs modified to aid in swimming and a pair of split eyes, one part above the surface of water and the other below, enabling them to see both sides at the same time, these beetles are very well adapted for their marine lifestyle.

Whirligig beetle

Adults are capable of carrying an air bubble, which help them breathe underwater as well. They also seem to be a very social group of insects, living and moving around in large groups, having an added benefit of evading predators.

Whirligig beetles

These beetles feed on debris that float around on the surface of water and also on any struggling insect or other small invertebrates that might fall in. Whirligigs’ have developed an amazing way of hunting its prey. They are attracted to the waves caused by the struggling victim and as a group they start honing on to it. Once honed in, they start biting nibbles off it.

They seem to employ some sort of simple Radar for this. The water ripples are the medium used to send messages here, as in the image below.

When the whirligigs detect the waves from a struggling insect that has fallen into the water, they start their rapid spinning action, sending ripples across the water’s surface. These water ripples bounce back from the victim. This light echo is detected by the whirligigs and they use this information to triangulate the location of their prey. How cool is that !!

Whirligig beetles

Water ripples are used to send messages and receive the echoes…!

They are also very beneficial insects. As scavengers they help in cleaning the water of dead and decaying matter.

All in all, it was lovely having seen these wonderful group of insects. These seem to have pioneered technologies that we humans have very recently been able to develop !

By | 2017-01-12T18:54:36+00:00 November 6th, 2014|Macros, Nature, Photography, Travel|12 Comments


  1. Deepa Mohan November 6, 2014 at 2:55 pm - Reply

    Was able to see the post immediately, since I had some time! Excellent post, and wonderful photos!

    • Santhosh November 6, 2014 at 7:08 pm - Reply

      Thanks a lot Deepa..

  2. Murugan Krishnan November 6, 2014 at 4:51 pm - Reply

    I have seen these insects in most of the mountain streams… But the triangulation which you explained has blown me off… Will have a closer look at these guys next time…

    • Santhosh November 6, 2014 at 7:08 pm - Reply

      Thank you Murugan…, these truly are wonderful creations…

  3. Karthik Hariharan November 6, 2014 at 7:44 pm - Reply

    Great documentation..awesome buddy!

    • Santhosh November 7, 2014 at 10:10 am - Reply

      Thanks da Karthik..

  4. Janani November 10, 2014 at 11:48 am - Reply

    I’ve been wondering for sometime now what these fellows were. Saw them from a distance a few times. Thanks for the write-up and the pictures. What interesting senses different creatures in nature use…

    • Santhosh November 10, 2014 at 5:56 pm - Reply

      Thanks a lot Janani….!

  5. Sivakumar Kolandaisamy June 13, 2015 at 12:38 am - Reply

    Very beautiful frames!
    Stunning clarity and details in all frames!
    Thoroughly enjoyed the frames!

  6. Kaustuv Chatterjee July 5, 2015 at 8:04 am - Reply

    That’s a brilliant write up peeking into the mysterious and evolved world of whirligig beetles….the photographs are stunning….thanks for sharing

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