Stalk eyed Fly

Lifer, a lifer man !…, said Shreeram, when I pointed him to a little insect flying around on the leaves while we were descending towards the famed and beautiful Jogi Gundi falls in Agumbe. It was very interesting to think of an insect as a lifer (Lifer, being, something that one sees for the first time in their life. ). Have heard that term many a times, among birders,  ( I call myself, one too… :-) ),  but heard it for the first time in the context of insects. However, come to think of it, it is so really true with these little creatures as well. They are so very diverse, hardly being noticed by us and also coupled with the fact that there is no guarantee of getting an opportunity of seeing a particular species yet again……anything and everything could be categorized as a lifer indeed.

The little insect in discussion was another of those amazing creations of the invertebrate world, little fly like insect called the Stalk-eyed fly. As the name suggests, the peculiarity lies in its eyes. The eyes are placed at the far end of very long stick like protrusions from its head, also known as stalks.

Stalk eyed fly 01 XL 660x405 Stalk eyed Fly Stalk eyed fly ( the red bulges at the end of the stalks are the eyes )

These flies belong to the family of Diopsidae and the stalk like projections carrying their eyes, distinguishes them from the rest of the crowd. The antennae are present on these stalks as well.

Stalk eyed fly 04 XL 660x405 Stalk eyed Fly Stalk eyed fly

Another interesting thing about these flies are the fights between the males of the species, for a mate. In such a fight, the males engage in a ritualized contest, sizing up each others’ stalks…and the individual with the broadest of the stalks, the widest separation between the stalks, gets the mate. We did notice this behavior, was very interesting to observe.

Stalk eyed fly 02 XL 660x405 Stalk eyed Fly Stalk eyed flies – Fight for a mate…

From Wikipedia,

 A rather remarkable feature of stalk-eyed flies is their ability, shortly after they emerge from their pupae, to ingest air through their oral cavity and pump it through ducts in the head to the tips of the eye stalks, thereby elongating them while they are still soft and transparent

 

Stalk eyed fly 03 XL 660x405 Stalk eyed Fly Stalk eyed flies – Fight for a mate…

These flies seem to a very interesting subject of research in many places, primarily looking into and analyzing as to why they did develop such a strange physical characteristic as the stalk. As mentioned before, in some species, it seems that the females tend to prefer mates with longer stalks, or males with a more wider separation between their eyes. The study or research is about this sexual preference. Whether the preference shown by the females was the trigger that led to the flies developing these unique characteristic or was the physical characteristic that lead to the sexual preference being shown by the females…….

Here’s for your further reading……

Stalk-Eyed Fly Research Group, UCL

Stalk-eyed fly – Wikipedia



Comments

    • Santhosh says

      @Sangeeta…They really are…To kindle your interest further, you could have a look at the amazing BBC series by Sir David Attenborough called ‘Life in the Undergrowth. Have seen parts of it being available on Youtube as well..

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