Foldscope

In the Field: Macro Photography, Microscopy & How Butterflies Create Color

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Working in the Amazon rainforest has its challenges. To name an obvious one, it can be difficult to take equipment into remote field sites in order to conduct research. Fortunately, we live in an exciting time, as technology is rapidly becoming simultaneously cheaper and more portable. In this post, I want to share a couple tools that I use to document small organisms in the rainforest, including the wing structures of butterflies and moths, as well as discuss the fascinating ways that biology creates color.

Macro shot of a Heliconius butterfly wing. The different colors (oranges, yellows, blacks) are caused by pigment production in each individual scale. MP-E65mm, ƒ/11.0, 1/125, ISO 200.

Macro shot of a Heliconius butterfly wing. The different colors (oranges, yellows, blacks) are caused by pigment production in each individual scale. MP-E65mm, ƒ/11.0, 1/125, ISO 200.

For starters, digital SLR cameras and macro lenses are powerful handheld tools that I use to document the biological diversity of tiny creatures that inhabit South America. I'm currently using a Canon 70D camera body equipped with the shockingly powerful MP-E 65 Macro lens. This lens is truly a macro beast, magnifying up to 5 times (aka a magnification ratio of 5:1) and allows me to get sharp images of microscopic structures, such as butterfly wing scales. For shots of the whole organism, I typically use the Canon EF 100mm f/2.8L macro lens, which I really love for its versatility and sharpness. In combination, the 100mm and MP-E 65 are a fantastic combination for macro photography in the field, allowing me to document small organisms such as insects, as well as zoom-in even closer to resolve  specific regions.

Here's a video explaining how these butterflies create color & using the Foldscope to investigate scale structures.

At our remote outpost in Sumaco, Ecuador, tinkering with my camera to photograph insects and butterfly wing scales.

At our remote outpost in Sumaco, Ecuador, tinkering with my camera to photograph insects and butterfly wing scales.

s an entomologist in the Amazon, I've been able to study a broad range of fascinating creatures, from Glowing Worms to Tentacled Caterpillars. More recently, I've become enthralled by the wings of butterflies and moths, and more specifically am curious about how these organisms produce such an incredible array of colors.

Macro of a Morpho wing, note the blue scales which do not contain any blue pigment. They contain nanostructures that bounce light back at the blue wavelength, a form of 'structural color'.

Macro of a Morpho wing, note the blue scales which do not contain any blue pigment. They contain nanostructures that bounce light back at the blue wavelength, a form of 'structural color'.

Butterflies and moths belong to the order Lepidoptera and all members have scales covering their bodies and wings (in Latin, lepis means scale and ptera means wing). With over 180,000 described species, the Lepidoptera are not only diverse in their numbers but also in their colors. Their color arises due to the nature of the scales that they produce and can be due to pigmentation as well as structural color. Whatever the origin, color results from an interaction between light and matter.

Like beautiful painted tiles, the scales on this Phantom butterfly range from shades of pink to entirely transparent. MP-E65mm, ƒ/11.0, 1/125, ISO 200.

Like beautiful painted tiles, the scales on this Phantom butterfly range from shades of pink to entirely transparent. MP-E65mm, ƒ/11.0, 1/125, ISO 200.

Owl Butterflies mating. The large eye spot on the hindwing is thought to startle potential predators like birds, a form of Batesian mimicry in which a harmless organism acquires protection by resembling a threatening animal. 

Owl Butterflies mating. The large eye spot on the hindwing is thought to startle potential predators like birds, a form of Batesian mimicry in which a harmless organism acquires protection by resembling a threatening animal. 

But even with the best macro lenses, it's still tough to resolve the scale structures on the wings of these insects. To get really close, we need to get into microscopy. But any of us familiar with using a microscope know that they are big, cumbersome, expensive pieces of equipment - not exactly compatible with field work. However, last year I came across an ingenious invention by a lab at Stanford, the Foldscope (an origami foldable microscope that costs about one dollar).

Some of the tools in my "mobile lab" kit: a foldable microscope, a DSLR camera with macro lens, a handheld gene sequencer, and my mobile phone.

Some of the tools in my "mobile lab" kit: a foldable microscope, a DSLR camera with macro lens, a handheld gene sequencer, and my mobile phone.

In the past I've posted about using the Foldscope to investigate small critters in the Amazon, but I've recently started using it to look at butterfly and moth wing scales, and it actually does a fantastic job.

An Amber Phantom butterfly with transparent wings. Combining macro photography and the Foldscope, allowing us to see the different scale structures that make up the colored and transparent regions of the wing.

An Amber Phantom butterfly with transparent wings. Combining macro photography and the Foldscope, allowing us to see the different scale structures that make up the colored and transparent regions of the wing.

Here is a dirunal moth in the family Uraniidae, notice how the scales that appeared green shift to a violet/purple color under the Foldscope. I imagine that the colored scales have microstructures that produce green wavelengths under normal sunlight conditions and changing the incoming light in the microscope has shifted the wavelength output. This is the reason Morpho butterflies appear iridescent blue, due to the structure of their nanoscales (called mullions).

Compilation of butterfly wing scales through macro photography and Foldscope microscopy, all taken while in the field in the Amazon Rainforest.

Compilation of butterfly wing scales through macro photography and Foldscope microscopy, all taken while in the field in the Amazon Rainforest.

Hope you enjoyed, you can check out more updates via Twitter, Instagram, and YouTube!

-Aaron

Testing a Foldable Microscope in the Amazon Rainforest

For the past few months I've been working with Stanford University researchers who developed an origami-style paper microscope, known as the Foldscope. We were the first researchers to take the Foldscope out to the Amazon rainforest and investigate the micro-world with nothing but this incredible device and a cell phone. Below is a cross-post from www.PeruNature.com, enjoy!

A couple of months ago, I received an interesting package in the mail. It looked like a standard manila envelope, but inside was a device that could quite possibly revolutionize the way we view the microscopic world. I’m referring to the Foldscope, an origami-based optical microscope that is small enough to fit inside your pocket. The real kicker: the entire cost of the instrument is less than one dollar.

Check out our video! Foldscope in the Amazon Rainforest

The Foldscope has received some recent and well-deserved media attention (the lab’s publication on this device recently made it in the top 20 papers in PlosOne for 2014) but I hadn’t seen many videos on the Foldscope being put to the test in the field. It seemed like there was a lot of potential for this invention but I wondered how it would fare on one of my expeditions through a jungle searching for unknown species. So I decided to assemble my miniature paper microscopes and travel to one of the most remote places in the world, the rainforest of the Peruvian Amazon, to give them a go.

The Results Long story short, this device is amazing. During my time in the Amazon rainforest, I was able to investigate tiny insects, mites, fungi, and plant cells from 140x to 480x magnification without requiring a large and expensive conventional microscope.

 The cells from a flower petal recorded by connecting a cell phone to the Foldscope

Some of the diverse arthropod specimens could potentially be new to science, so it was really exciting to document images and videos of these organisms right there in the field by connecting my phone to the Foldscope.

 An unknown species of mite documented by connecting a cell phone to the Foldscope

 A spider infected by a parasitic fungus known as Cordyceps. The circles show regions of the fungus viewed under the Foldscope

In the video, I investigate bizarre structures on a plant, which are known as leaf galls. These are sometimes created by insects, but they usually have to be taken back to a lab and inspected in detail under a microscope. Lucky for me, I had the Foldscope in the field! It turns out these were in fact due to insect larvae, which burrowed into the leaf and tweaked the chemistry of the plant to produce galls. Even with macro photography, I couldn't get much detail of the larva, but at 140x magnification under the Foldscope I was able to document the morphology of this unknown critter.

 Top left, a leaf is covered in galls. Top right, a cross-section of a gall; notice the tiny insect larva living inside! Bottom, the larva was placed under the Foldscope and viewed on my cell phone. Pictures and videos were recorded in real-time out in the Amazon rainforest.

 Top left, a leaf is covered in galls. Top right, a cross-section of a gall; notice the tiny insect larva living inside! Bottom, the larva was placed under the Foldscope and viewed on my cell phone. Pictures and videos were recorded in real-time out in the Amazon rainforest.

Suspecting that the galls were formed by some sort of wasp or fly, I later got in touch with a couple of Diptera (fly) experts, Morgan Jackson (@BioInFocus) and Dr. Stephen Gaimari, who helped identify the gall forming culprits as a possible species of fly belonging to the family Cecidomyiidae.

Final Thoughts

The research team, led by Dr. Manu Prakash, seeks to “democratize science” by developing tools that are able to scale up to match problems in global health and science education - and I believe they are doing just that with the Foldscope. This device is cheap, easy to use, and broadly applicable whether you're a curious young student, a medical professional in the field, or someone who is interested in the numerous tiny things that surround us. Until now, I've never had a device that made viewing and sharing the microcosmos so accessible.

 Assembling the Foldscope is simple and takes less than ten minutes

 A closer look at the moss covering a tree in the tropical rainforest

 Morphology of a neotropical pseudoscorpion - all images were taken in the field

 The stinger of a honey bee viewed under the Foldscope

 I took the Foldscope with me to the beach in Santa Monica. Bottom left are kelp cells and bottom right is an unknown critter I dug out of the sand (some sort of worm?)

A breakdown of the unit costs for Foldscope components in volumes of 10,000 units, not including assembly costs (Cybulski, Clements, & Prakash 2014). The total cost of the Foldscope ranges from $0.58 to $0.97.

The Prakash lab will be starting with phase 2 of the project shortly, which will involve much larger production runs. So if you want your own Foldscope, be sure to check out their application process through www.foldscope.com and for inquiries see their contact page. Citation: Cybulski JS, Clements J, Prakash M (2014) Foldscope: Origami-Based Paper Microscope. PLoS ONE 9(6): e98781. doi: 10.1371/journal.pone.0098781

You can follow Aaron for more updates on Twitter @AaronPomerantz and the Stanford University Researchers @PrakashLab