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UltravioletPhotography

Anisoptera [Fluorescent Dragonflies]


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On the day I received the ZWB1 filter for my Tank 007 TK-566 UV torch I found two half dead dragonflies in the road on my way to work. On casual inspection they looked intact, would flap their wings when stimulated, but without trying to get away. I often see dead dragonflies and juvenile dead (flat) squirrels at this location. I had a little bouquet of flowers set up in the lab for something for them to hold on to. They remained still for long periods except when initially stimulated by the UV light, but not all frames were completely sharp. The light source in the visual light frames is the overhead fluorescent tubes of the lab.

UVIVF:

#1

2017-06-20-2018E-4886-md.jpg.173795271bb8eb56c67a79a5c60d0cd5.jpg

 

105mm f/4 AIS Micro Nikkor @ f/8 on unmodified D7100, 8sec, ISO 100

 

 

VIS:

#2

2017-06-20-2046E-4898-md.jpg.adc39d3899fda9c9fb70bf26180ecf92.jpg

 

105mm f/4 AIS Micro Nikkor @ f/8 on unmodified D7100, 1s, ISO 100

 

 

UVIVF

#3

2017-06-20-2049E-4897-md.jpg.a7a669bac3786b880e3fa247d14be563.jpg

 

105mm f/4 AIS Micro Nikkor @ f/8 on unmodified D7100, 20s, ISO 100

 

 

VIS

#4

2017-06-20-2057E-4900-md.jpg.03b620464d58f1369dea095f1cb27537.jpg

 

105mm f/4 AIS Micro Nikkor + PN-11 @ f/8 nominal on unmodified D7100, 1.3s, ISO 100

 

 

UVIVF

#5

2017-06-20-2058E-4901-md.jpg.1191b73e1bc3343ed58bd7e2d10e006b.jpg

 

105mm f/4 AIS Micro Nikkor + PN-11 @ f/8 on unmodified D7100, 20s, ISO 100.

 

 

This is likely the second specimen, VIS :

#6

2017-06-20-2127E-4930-md.jpg.fff7c06248f4926ebf116fd6278e3ba7.jpg

 

105mm f/4 AIS Micro Nikkor + PN-11 @ f/8 on unmodified D7100, 2s, ISO 100

 

 

UVIVF shows some frontal damage more clearly.

#7

2017-06-20-2141E-4942-md.jpg.3f48415607de3272eabc11ce200d58f3.jpg

 

105mm f/4 AIS Micro Nikkor + PN-11 @ f/8 on unmodified D7100, 20s, ISO 100.

 

 

 

UVIVF - First specimen - Crashed and down.

#8

2017-06-20-2332E-5056-md.jpg.77db59c4581dbeccec781f4d920ab6b2.jpg

 

105mm f/4 AIS Micro Nikkor + PN-11 @ f/8 on unmodified D7100, 8s, ISO 100.

 

 

 

UVIVF - forensic frontal shot (the black bench top shows blue fluorescence).

#9

2017-06-21-2107E-5101-md.jpg.387e90626da14bea6f70b9eb0c9bb58c.jpg

 

105mm f/4 AIS Micro Nikkor +PN11 @ f/8 on unmodified D7100, 25s, ISO 100.

 

 

UVIVF - forensic side shot

#10 Aeshna eremita (Lake Darner)

2017-06-21-2110E-5103-md.jpg.298e0cd954dc9e0197fe340d628c5d29.jpg

 

105mm f/4 AIS Micro Nikkor +PN11 @ f/8 on unmodified D7100, 20s, ISO 100.

 

 

VIS with bottom side of fern:

#11

2017-06-21-2150E-5122-md.jpg.70a9a609d6bf16faac8a48d5d2a76b14.jpg

 

105mm f/4 AIS Micro Nikkor +PN11 @ f/8 on unmodified D7100, 1s, ISO 100.

 

 

UVIVF parting shot

#12

2017-06-21-2153E-5126-merge2-md.jpg.b777a77d16c16c8f923922472c548d83.jpg

 

105mm f/4 AIS Micro Nikkor @ f/8 on unmodified D7100, two frames with different lighting angle averaged, each 15s, ISO 100.

 

 

-- Next day they were both dead. RIP dragonflies.

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Beautiful photographs. And so interesting. Thank you, Øivind. And thank you, Dragonflies.

 

Would you mind putting a general location where you found these Dragonfiles? I'm assuming in Alaska somewhere. Perhaps someone would eventually be able to identify the genus or genus/species if they had a general idea of the location.

 

Really, those last two photos are impressive. (And, do feel free to cross-post and share this lovely work elsewhere. I'm thinking that these last two should be also shown on NG?)

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Thanks for the kind comments all of you.

Andrea, these were collected on North Tanana Loop in Fairbanks, Interior Alaska. GPS coordinates from an AW1 image within meters of the location: 64°51.727' North, 147°49.687' West.

Dragonflies are the State Insect in Alaska, very popular both by appearance and because they catch the mosquitoes! The latter is Alaska's "State Bird" :D .

 

I need to look further into the identification of the species when I get more time. These ones are quite common around here. Patterns between the wings are supposed to be important clues. I also know some local experts I could ask if I am lazy.

 

Yes, I wondered if the fairly bright florescence of the eyes might interfere with their vision. Thanks John for the link to that paper, looks interesting. Their vision must also be crucial to avoid crashing into things. Hitting a car as likely in this case even at the low speed limits at the location is apparently lethal.

 

Edit: The side view shot in #10 (I have a reference image showing the stripes better) seem to indicate that it is an .Aeshna eremita (Lake Darner).

The shape of the stripes in the first image seems different, first suggestion was an Aeshna palmata (Paddle-tailed Darner), but our former Ph.D. student who did some work the dragonflies was not sure. I also copied our entomologist at the Alaska Museum of the North, but have not heard back yet, he might very well be in the field.

 

Edit2: Our entomologist at the museum, Derek SIkes got back to me today and confirmed the importance of the lateral stripes for identification and agreed to the identity of Aeshna eremita. He was very enthusiastic about the images too.

 

Fairbanks-location-MAP-001.jpg.509b8282429940f1a28b1715e7e2baad.jpg

 

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Øivind, I tweak the title just to fit our indexing program.

 

Thanks for the identification. It's always interesting to know what the particular specimen is.

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