Author Archives: Brian Brown

Massive tropical fly inventory funded by the United States National Science Foundation

A tachinid fly photographed by Wendy Porras at Zurqui

I am excited to announce that NSF has funded Dr. Art Borkent and I to conduct an ambitious project to discover and enumerate all of the flies at a tropical site in Costa Rica. The site, called Zurqui de Moravia, or Zurqui for short, is about one half hour north of San Jose in the cloud forest just outside Braulio Carrillo National Park. We have been collecting there for the past 15 years, and have found one of the most diverse and interesting faunas in Costa Rica. Now we are extending our studies to ALL of the Diptera found there!

This project is a collaboration of more than 40 experts worldwide, as well as Costa Rica’s Instituto Nacional de Biodiversidad (INBio). Together, we will collect extensively and identify all groups, even the “impossible” ones like ceratopogonids, cecidomyiids, and phorids. We expect to find a number of species that will surprise even us!

This will be the first time that such an intense effort will be made for any mega-diverse group of insects in the tropics. We were inspired by Terry Erwin’s fogging samples in Peru (and elsewhere), but wanted to go a different route in understanding tropical biodiversity. The “All Taxon Biodiversity Inventory” (ATBI) model appealed to us, but we knew we had to restrict our collecting to prevent the project from getting out of hand. We therefore decided to collect in just two small ravines in an area 100 m x 200 m in size.

We are calling the project the “Zurqui All Diptera Biodiversity Inventory”, or ZADBI. Collecting will start in September; meanwhile we are getting organized for the massive job of collecting, preparing, and identifying the tens (or hundreds) of thousands of specimens we will collect. Of course, we will be broadcasting our discoveries and experiences both here on flyobsession and on the project’s website (TBD). Get ready for some more cool flies!

More microfraction miracles

I call these “miracles” not in the religious sense, but in the unlikelihood that I would notice them in a “normal” sample with all the macro-garbage obscuring them.

The first is a male, perhaps of the genus Metopina, with the thick costal vein almost as long as the wing.

Metopina group male

Next is a bizarre female termitoxeniine that has not yet shed its wings.

female termitoxeniine

A relatively “normal” wingless female Chonocephalus.

female Chonocephalus

Finally, a flattened male of a new phorine genus with a short costa.

new phorine genus

And I still have many more vials to look through! Life is good.

All photos were made by Inna-Marie Strazhnik, who is a superb artist.

Microfractions rule!

I am sorting through a bunch of Malaise trap samples from Thailand from which all the insects larger than about 2 mm have been removed. The absence of larger insects makes all the tiny ones stand out, so these samples, the “microfraction” are golden. They are full of treasures: usually overlooked tiny things like Chonocephalus, termitoxeniines, and weird Metopina group males. I’ll publish more photos soon, but here are a couple I photographed previously.

a Metopina group female

new phorine genus

Note the shieldlike crest on the back of the head in the second photo. Totally bizarre.

Microfractions represent yet another largely unexplored frontier of tropical phorid diversity. After nearly 30 years of doing this, I can still be amazed and awed by “my” flies.

Problems photographing flies. 4. What type of light.

Here are some options; look at the abdomen:

popup flash - the worst

Significant “speckling” here, where each bristle reflects the flash. Ugly.

external flash on camera

flash with softbox diffuser

natural light

The natural light is so much better. Look at the details visible (click on the image to see a larger version). Too bad it is impractical.

I could go on and on about this, but even I’m getting bored. Besides, someone else has a great website about macrophotograpy lighting. Look at this site for amazing images and how they were made: http://orionmystery.blogspot.com/ . I don’t have to reinvent the wheel here.

Back to flies next time.

Problems photographing flies. 3. You need light.

Okay, based on parts 1 and 2 of this series, you want to use high apertures (lens f-stop settings) to get lots in focus, but you need to use intermediate apertures to avoid diffraction blurriness. Either you have to focus stack (often impractical in the field) or accept a compromise f-stop like f11. So how does f11 work for you?

In all but the brightest light, f11 (or f8) will require long exposure times, giving ample opportunity for you or the fly to move, blurring the exposure. We’re back to either needing a motionless fly (unlikely) or, this time, more light.

Wait, can’t you just dial up the ISO (sensor sensitivity) on your new digital camera so you can use a faster shutter speed? Yes, but you increase the digital graininess (“noise”) in the photo, such that resolution at high magnifications is destroyed.

Here are a series of closeups of bristles on a tachinid fly showing this effect:

ISO 100

ISO 200

ISO 400

ISO 800

ISO 1000

ISO 1600

ISO 6400

This series of shots tells me that, for my camera, ISO 200 is about the same as 100. For ISO 400-800 I get some degradation, but it is still pretty good. Above ISO 800, thing get pretty mushy. You need to check this in your camera, too.

The result is that changing ISO only helps me a little. If I want the highest quality images, I need more light. How to get this light is my next topic.

Why so spiny?

Acontistoptera female
I got a lot of questions about why yesterday’s fly would be so spiny. I can think of two plausible answers, both of which might be right.

Firstly, such spiny flies are almost invariably found in species associated with ants, especially army ants. As evidence for this, here are 3 flies from the New World tropics found with Labidus army ants: Acontistoptera, in which the long setae (bristles) are found almost only on the wing rudiments, Adelopteromyia, which are spiny on the wing and on the body (especially the head), and Xanionotum, which has multiple rows transversely across the abdomen.
Adelopteromyia female
The large setae could be used to fend off attacking ants, like a porcupine, or for sensory purposes in the darkness of underground ant colonies. Or both. One thing to keep in mind is that the flies probably can move the setae, erecting them or laying them down. They are much more flexible, mobile, and speedy than you might think, as they literally runs circles around the host ants.
Xanionotum female

A brief respite from photography posts: another bizarre phorid

My friend in New Zealand, Hugh Oliver, saw the picture of the wingless female phorid in my last blog post, and asked for more photos of weird phorids. I didn’t even know he was looking at my blog, but just for him I am posting this photo of an extremely bizarre specimen we found just this week in material from Thailand. I think it is a female of the genus Rhynchomicropteron, but if so, it is an extremely unusual one! Thanks to Lisa Gonzalez for pointing it out to me, and Inna-Marie Strazhnik for photographing it. Maybe it can be number 16 in Terry Wheeler’s posts about why flies are great.

female Rhynchomicropteron?

Problems photographing flies. 2. To stack or not to stack?

female Aenigmatias

As I showed in the last post, at high magnifications you can only have a small amount of your subject in the sharpest focus because diffraction limits useable depth of field. Now you have two choices: stacking or settling for some different compromise.

The image above is a blended stack of 25 images, all of which only have a bit of the fly in focus. I used a program called Zerene Stacker to do this, but there are other options. You can make some phenomenal images this way (just look at the forums at www.photomacrography.net), especially using tens to hundreds of source images, but there is a catch – your subjects have to be motionless, preferably dead. Some field photographers can get short stacks of a few images of resting flies, but generally flies are 2. active. For me, it is better to pick a compromise lens setting like f 8-11, as discussed last time, to get good shots of lively, moving flies. If you want more information on stacking, though, see the free resources at www.macrostop.com.

Next: how do you get enough light to use f 11?

Problems photographing flies. 1. Of what is your camera capable?

A tachinid fly - looks good, right?

Flies are fantastic subjects for photography, but they present many challenges because they are

1. small,

2.active,

3. often metallic and bristly.

All of these are factors that cause problems that I’ll discuss in the next few postings.

[The reason I’m writing about this is that there is so little good macrophotography information about insects like flies. I assume interested readers know the basics of 35 mm digital photography. If this subject doesn’t grab you, go back and re-read the last post by Lisa Gonzalez, which was a real crowd-pleaser]

When you photograph small things at high magnification, your depth of field is frighteningly shallow. Take a shot at f 1.4 and you’ll get maybe one tarsomere and a wingtip in focus. The rest will be a blur. Therefore, you need  to close down to f 22 or f 32 to get everything in focus- correct? Unfortunately, when you do this, you start to distort the image through diffraction. It’s not really a problem when photographing big things (like landscapes), but flies are 1. small.

Above is a good-sized tachinid fly. I photographed it with my camera (Nikon D-7000) on a tripod, using a 125 mm macro lens set at f 22. At this magnification it looks pretty sharp, but look closer (below). You’ll softness from diffraction that no fly obsessed photographer (and I hope you are one) would tolerate. And since most flies are smaller than this tachinid, what we see in this magnified view is ALL we’ll get.

f 22 -blech!

At the next setting, f 16, sharpness is definitely better. Scroll down to see other settings.

f 16, a little better

f 11, better yet

f8 - sharp

f 5.6 - who knew?

The problem, of course, is that by f 5.6 the legs are all out of focus. You have to pick a compromise (f 11 works for me) or do something else, photostacking, which only works well with stationary objects (and remember, flies are 2. active). More compromises are ahead.

To get the best results, you first need to know what your camera can do. Everyone needs to test their camera and lenses this way to see what is possible. Then you can move on too what is practical.

Next- how do you get to use that f 11 setting?