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Garden pests - a practical use for UVIVF

Fluorescence
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#1 Damon

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Posted 14 November 2017 - 05:08

I noticed this summer my tomatoes were being devastated by some kind of leaf chewing pests. I suspected tomato hornworn but they are really hard to see during the day as they are exactly the same color as the leaves/plant. Plus I have a lot of tomato plants and it would take time to look them all over closely. I did find one to confirm that's what it was.

A couple days later I was out wandering around at night with my convoy UV light and went into my garden as there are always weird things in there Fluorescing. I hit my tomato plants with the lights and the tomato hornworms were glowing so bright I could see them easily 10 ft away. In about 4 minutes I spotted all 15 of them and dispatched them.
The rest of the season I used this method and got every single one in short time. What an easy (and fun) way to locate an otherwise tricky to find pest.
I am now wondering what other problem bugs can be found. Maybe if gardeners knew about this some would forgo the pesticides.

Visible light: Canon 1D Mark IV Unmodified, EF100mm f/2.8 Macro USM, LED headlamp, 1.6s @ f/7.1 ISO 200, No Filters.

UVIVF: Canon 1D Mark IV Unmodified, EF100mm f/2.8 Macro USM, Convoy S2+, 1s @ f/7.1 ISO 200, No Filters.

Attached Images

  • Attached Image: Tomato Hornworm visible©DNoe_resize.jpg
  • Attached Image: Tomato Hornworm UVIVF©DNoe_resize.jpg


#2 Cadmium

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Posted 14 November 2017 - 05:39

Oooo! Wow! That wins the prize! Very nice!

Edited by Cadmium, 14 November 2017 - 14:21.


#3 Andrea B.

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Posted 14 November 2017 - 06:08

Perhaps write up your finding about the fluorescent hornworms for a gardening magazine? It’s a good practical suggestion. I’d much rather use a UV-torch than any pesticide.

{{Funny thing is, these caterpillars are so pretty under black light that I wish they didn’t have to be “dispatched”. But believe me, I do that too, ‘cause nothing is permitted to munch on my tomato plants!! However I do sacrifice a lot of flat-leaf parsley for the swallowtail caterpillars who may nom said parsley till they’re stuffed full.}}
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#4 Adrian

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Posted 14 November 2017 - 08:24

Living in England with an increasingly impoverished insect fauna I would love to see these splendid insects in my garden (though would probably change my mind if they started to eat my tomatoes!).
Do you know if other hawkmoth (or any other) larvae fluoresce like this?

For interest there is a good folio of invertebrates fluorescing on the web site of Nicky Bay: https://www.flickr.c...57635395934316/

I would love to have some of those in my garden too!

#5 JCDowdy

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Posted 14 November 2017 - 14:59

Excellent!!!

#6 Andrea B.

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Posted 14 November 2017 - 19:00

Adrian, those hornworms are extremely destructive on tomato plants, I can assure you. :D

But you can plant the garden items which attract butterflies to lay their eggs on that plant. I have a list for the US, so I'm sure there is a butterfly larval plant list for England somewhere. As referred to above I plant scads of parsley so both we and the Swallowtail butterfly caterpillars can have some. Plants in the parsley family are their larval food. In the years when I have several Swallowtail caterpillars, we get much less parsley for our soup. Those guys can really eat a lot !!

Thanks for that link. Nicky Bay is an excellent insect photographer. Wow! (I looked at other non-fluorescent work, too.) I like the lights he was using in the small avatar photo. Those look quite handy with the bendy arms. Wonder who makes them?
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#7 Damon

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Posted 15 November 2017 - 04:32

Thanks!

I agree with Andrea, Nick has some really cool work there Adrian - so thanks for sharing that.

Yeah I also thought they were almost too amazing to kill. I did think about taking them all away somewhere else but I got lazy. If anyone has taken dedicated time on tomatoes in Jersey (the best around IMHO) and watched them get annihilated in a couple nights from an infestation they would soon be buying some Convoys! :)

Nature has a partial solution though if you can give her time to implement it. Not for the faint of heart however.

The Braconid wasp (applied to a variety of species) will parasitize loads of insects and the tomato hornworm is one of them. They are a gardeners friend. They sting the caterpillars and lays many eggs inside. Once these hatch they begin eating their way around inside the caterpillar. Kinds like people eating their way through a 10 ft high 30 ft long canoli.
They leave vital organs for the last so as to keep it going for a bit but are literally eating it alive. When they are ready, they chew through the skin and spin a cocoon and become pupa hanging off like fuzzy sickly sacks of caterpillar mush, and of course eventually the mature into more adult wasps. As you can imagine, the caterpillar is no longer chewing tomato leaves. Yay!

I found a couple of these on my tomato plants and so left them there. I took some pics of course. Be ready to be grossed out. :)

Visible light: Canon 1D Mark IV Unmodified, EF100mm f/2.8 Macro USM, LED headlamp, 2s @ f/9 ISO 100, WB 5200 No Filters.
Attached Image: Tomato Hornworm parasite_visible©DNoe_resize.jpg




UVIVF: Canon 1D Mark IV Unmodified, EF100mm f/2.8 Macro USM, Convoy S2+, .6s @ f/7.1 ISO 100, WB 5200 No Filters.
Attached Image: Tomato Hornworm parasite_UVIVF©DNoe_resize.jpg

The caterpillar now shows a decay of its vitality and healthy bright blue Fluorescence coloring.

-D

#8 Andrea B.

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Posted 15 November 2017 - 22:25

That is truly interesting about the change in fluorescence. Wonder why the caterpillar has those glowing head and tail patches? What purpose does it serve if nobody ever sees it I wonder.

And truly disgusting otherwise!! Yuk-o-rama!!
Geezie jabbers, nature can be so cruel.

Cool work, Damon.
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#9 Mark

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Posted 16 November 2017 - 02:13

This is a very cool find Damon. Thanks for sharing.

Like Andrea mentioned above, I also wonder what the purpose of the bright patch on the head could be. It occurs to me that it indeed may never be seen, again as Andrea suggests/questions. But - this is the UVIVF view we are taking. If instead you were to get a UV shot ... then we may see that the patch is UV dark - something some can see. Maybe an indication to birds - an attempt to mimic an eye (to trick would be predators)? Perhaps the wasp has figured out the ruse and instead uses it as a means of identifying / targeting the host for its young? Or maybe something completely unrelated - I wouldn't be surprised if nature surprises me here.

#10 Damon

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Posted 16 November 2017 - 04:57

I sometimes think if all we ever saw were UVIVF and then found ways to see visible light we would be saying "now why does that tomato hornworm have those white stripes on it's side, and look, the white head and tail patches are gone". :)

It's getting late here but I have some ramblings on this:

If we think of the parts of an animal that would need to be a little tougher than the rest of its body due to defense, frequent abrasion, offense etc., they would many times be the head (and horn if it has one), rear end and sometimes feet. Rhinos with horns and thick plates up front and thick plated rear ends for ex.
If we extrapolate that to the previous hornworm caterpillar it just might be that these white parts are made up of more or a different kind of protein and Fluoresce due to their chemical make up only. The white markings mean nothing as far as our traditional “why do they fluoresce” but are simply the by product of the thicker skin. With the caterpillar, the head is always rubbing against plants, the horn is a defense, the tail end might be getting attacked etc. so could use some extra toughness/thickness in those areas.

Take a look at this awesome Imperial moth caterpillar below. As thick as your thumb and long as your index finger. A monster of a caterpillar.
It also is expressing some white in similar areas in the UVIVF image. The horns are especially white and could be used for defense so would have to be thicker and maybe a different chemical make up.

It's these wonderful mysteries that keep my interest.

-D

Visible light: Canon 1D Mark IV Unmodified, EF100mm f/2.8 Macro USM, LED headlamp, 1s @ f/8 ISO 100, No Filters.
Attached Image: Imperial moth caterpillar visible light©DNoe_resize.jpg


UVIVF: Canon 1D Mark IV Unmodified, EF100mm f/2.8 Macro USM, Convoy S2+, .8s @ f/8 ISO 100, No Filters.
Attached Image: Imperial moth caterpillar UVIVF©DNoe_resize.jpg

#11 Andrea B.

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Posted 16 November 2017 - 06:10

What a beauty!

Some caterpillars are equipped with poisonous hairs or horns. Maybe the bright areas are warning signals. :D

Good speculations Damon about thickened head areas, etc.
I agree that these little mysteries are quite fascinating.

We are sooooo lucky that we get to see such awesome stuff under our UV lights or thru our UV-pass filters.




How is the caterpillar response to the UV light? Are they OK the next day?
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#12 Damon

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Posted 17 November 2017 - 03:58

This Imperial moth I took quite a few pics of. I took it home and put it on some white pine which is what I found it on. It chomped for a few more days, and then left to go pupate under ground. UV didn't appear to do much if anything to it.

-D

#13 Cadmium

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Posted 17 November 2017 - 07:20

These are all very amazing.