w w w . i n d i a w i l d s . c o m
home
about Sabyasachi Patra
diary
forums
image gallery
contact IndiaWilds
Home
About
Diary
Forums
Gallery
ContactUs

User Tag List

Results 1 to 6 of 6

Thread: Stalk-eyed Flies

  1. #1
    Join Date
    15-04-09
    Location
    Goa/Mumbai
    Posts
    3,121
    Mentioned
    0 Post(s)
    Tagged
    2 Thread(s)

    Default Stalk-eyed Flies

    Among the enormous assemblage called the insects, the fly order Diptera is certainly one of the most fascinating, with a host of alien-like members, many of which are also worthy of recognition- the hoverflies are remarkable aerobats, and certain fruit flies from Hawai'i have their own elaborate courtship dances. One of the most weird and wonderful groups of flies, one that literally "stands out", are the stalk-eyed flies- Diopsidae.

    There are not a lot of flies that one would add to a wish-list and strike off as a "lifer" upon a sighting- but the stalk-eyed flies are an exception. Not only are they amazingly unique to observe, they are not exactly easy to find.

    The first time I saw stalk-eyed flies was on TV; they were featured in the natural history documentary series Life. Later, I encountered this fly (Diopsis sps.), quite by chance, twice in real life- the first time in Arunachal Pradesh, and then a second time much closer to home, in Karnala, Maharashtra.

    What is perhaps most fascinating about stalk-eyed flies (once you grasp how weird they look) is the process by which their head develops into the shape that gives them their name. After emerging from the pupa as an adult, the fly actually pumps air into its head, expanding the sides of its head near the base of its eyes. Eventually, it pushes the eyes so far out that they stand out on very long stalks.
    (Here is a link to a video clip, the same footage featured in Life - http://videos.howstuffworks.com/disc...alks-video.htm)

    The second unique aspect is how the males use their bizarrely shaped heads for courtship. Firstly, the farther a male's eyes project, the more superior his genes, and hence, by natural selection, he is the one that gets a mate. Secondly, stalk-eyed flies are documented using their wide heads as battering rams, headbutting each other into submission. As always in the animal world, fights do not happen without adequate warnings, and the rivals raise their wings to signal their intent. These flies are territorial, and they use these methods to safeguard their leaf (or other territory).

    Stalk eyed flies are found mainly in humid forests, most commonly by stream sides, on leaves during the day and 'roosting' on exposed plant roots and stalks at night.

    This fly's biology is a wonder in itself, but also turns one's attention to another, bigger wonder- the extreme lengths to which life evolves!



    [Pictured in the following frames are the two stalk eyed flies I have encountered. Both were found close to streams, on short vegetation. Both were about 6-7 mm long.]

  2. #2
    Join Date
    15-04-09
    Location
    Goa/Mumbai
    Posts
    3,121
    Mentioned
    0 Post(s)
    Tagged
    2 Thread(s)

    Default

    Diopsis sp. | Karnala, Maharashtra | Oct 2014
    Attached Images Attached Images  

  3. #3
    Join Date
    15-04-09
    Location
    Goa/Mumbai
    Posts
    3,121
    Mentioned
    0 Post(s)
    Tagged
    2 Thread(s)

    Default

    Diopsis sp. | Seijosa, Arunachal Pradesh | Nov 2013
    Attached Images Attached Images  

  4. #4
    Join Date
    24-11-08
    Location
    Bangalore
    Posts
    15,869
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Default

    Very interesting description of these stalk-eyed flies. When I first saw the photographs, I thought it had something like antennae. After reading the post I realised those were its eyes. Nature is really amazing. Good details. Nicely captured. Thanks for sharing the detailed description of these flies.

  5. #5
    Join Date
    17-12-08
    Location
    Bangalore
    Posts
    4,589
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Default

    Never knew about this. Thanks for sharing. Now I learn a little more.

  6. #6
    Join Date
    18-09-09
    Posts
    3,609
    Mentioned
    0 Post(s)
    Tagged
    2 Thread(s)

    Default

    Nice write up Abhishek. very intresting.

    TFS
    Roopak

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •