Photo Synthesis

…these would be the beetles of choice.

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Onthophagus taurus dung beetles,
showing size and horn variation among males.

Dung beetles in the widespread genus Onthophagus sport a bewildering array of horns. Not only do the horns of different species vary in shape, size, and the body part from which they grow, many species show a marked dimorphism within the males.

Consider these two male morphs of O. nigriventris, an African species:

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The big guy on the right is a major male, and he does pretty much what you’d expect. He bullies his way around with shows of bravado, guarding his burrows with impressive weaponry and beating up on lesser males in hope of monopolizing the females. The lesser-endowed guy on the left is a minor male, and as you might guess he’s not much of a fighter. He is small, agile, and sneaky, gaining access to females on the sly. Indeed, he even looks a lot like a female, perhaps enough to fool the brutes.

As it turns out, the two morphs are developmental variants. Large male larvae have the resources to grow the massive horn and metamorphose into effective fighters. Small male larvae don’t gain anything by growing the horn, as they’re destined to lose out in any confrontations with other males. So at a particular point in development they shunt their limited resources into testes instead of horns.

And the female herself? Here she is!

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The fantastic variation within and among Onthophagus species have made the genus a biologist’s playground. These dung beetles are an exemplary system where behavior, ecology, development, and phylogeny can be integrated to form a comprehensive picture of the evolution of novel traits. I can’t cover all the research here, but instead I’ll point you in the direction of dung beetle gurus Doug Emlen and Armin Moczek(*).

Another shot of the O. nigriventris major male:

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Here’s O. gazella, an African beetle that’s been introduced worldwide to help manage cattle dung:

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Finally, another O. taurus male. Go Longhorns!

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(*)my thanks to secret sources deep within the Moczek lab who arranged the O. nigriventris and O. taurus for a photo shoot last weekend.


photographic notes:

The images with the plain backdrop were done in a white box.

What’s a white box? Exactly what it sounds like: a large cardboard box colored white on the inside. It’s a mini-studio for insects. When I fire a strobe inside the box, the box flashes with a lovely diffuse white. It gives enough light for a good fast exposure but without the glare of a point-source. Perfect for capturing the intricate sculpture of a beetle’s integument.

Comments

  1. #1 eNeMeE
    April 18, 2009

    Cool pics. Thanks.

  2. #2 Art
    April 18, 2009

    Outstanding pictures.

  3. #3 PalMD
    April 18, 2009

    Have I told you yet how much this blog rocks?

  4. #4 Alex
    April 19, 2009

    Thanks guys! Glad you like them.

  5. #5 Rob Knell
    April 19, 2009

    These are really outstanding photos. I’m very impressed with how you captured the colours of the cuticle. Might have to build myself a white box to have a play with.

    I have been doing some work on O. taurus recently – they are not only spectacular beetles, they are also amazingly strong. Need to write that paper.

    Cheers

    Rob Knell

  6. #6 Anon
    April 23, 2009

    Speaking of white boxes… Do you take requests? Could you post some pics of your equipment? How big is a white box? Do you have several, for different sizes of shots? How near are the strobes? I think I can picture quite a bit based on your descriptions, but I would love to see that the tracing paper on the flash is held on with duct tape, or neatly cut cello tape, or wrinkled and held to the flash with a rubber band…

    I love the photos, I love the descriptions… I love reading of the ratios of how many shots you took to how many you considered usable!

  7. #7 Ralph Voss
    May 6, 2009

    Alex:
    I know very little about dung beetles. Much of what I do know I learned from one of your compatriots there at U of I, Dr. Jim Nardi. What a coincidence I should stumble onto this website. Please say hello to Jim for me. Ralph Voss

  8. #8 Bob Sedlak
    May 17, 2009

    Anyone have dung beetles to sell, I have a pasture that I’m trying to reclaim from the top soil being stripped. My cattle leave plenty of dung but it just dries out and blows away. I thought the DB’s would help reestablish the lost humus.

    Thanks, Bob

  9. #9 Kate
    September 16, 2009

    I am an American living in Kenya, and I came across your site as I was trying to classify a beetle my kids find in the yard. I believe it’s a dung beetle of sorts. We actually find various species. I enjoyed your photo tips bc I had a difficult time capturing the ‘dudu’s’ detail. Thanks!

  10. #10 World Amazing Records
    March 25, 2010

    Onthophagus taurus dung beetles is now became world strongest insects in the world – i have added in my blog world amazing records – really amazing pictures you snaps.

    Appreciated…..

  11. #11 oyun hilesi
    May 14, 2010

    I learned from one of your compatriots there at U of I, Dr. Jim Nardi. What a coincidence I should stumble onto this website. Please say hello to Jim for me. Ralph Voss

    thanks…very nice post

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