X-ray of moth in fly trap

We now have a image made from our 3D scan of the moth in the fly trap that we scanned many weeks ago (see post What settings should be used on the x-ray machine?). False colours have been used to make the features stand out.

Faintly at the top of the image you can see the moth's wings sticking out of the trap

Below that you can see the edges of the trap where finger like strands have linked together

You can also see the moth's eyes!

And you can make out the veins in the leaf of the moth trap

What happens when a Venus fly trap dries out

A few weeks ago I was away for a conference. It was very interesting and I have a great time. However, while I was away the friends I had asked to look after the fly trap forgot and it dried out! I have been watering it a lot since I got back and it is beginning to recover.

You can see a lot of the heads have gone black but there are plenty of new green stems growing. Unfortunately the flowers I planted didn't do so well. In the pictures below you can see that just behind the heads of the flowers the stems have gone black. This blackness continued down the length of the whole stem over time.

I pulled one of the flowers out to see if it have grown roots before it died, and it had! In the picture below you can see a few very short roots that have bound to sand grains. So if it hadn't died due to lack of water it would probably have grown into a new plant. I will try again if the Venus fly trap grows any more flowers.

The fly trap got fried

It seems that 3 hours in the x-ray machine was too much for our fly trap. The edges of the trap got burnt and dried up. The head containing the moth is dying. Here is a picture. You can see where the moth's wings are sticking out and where the trap has gone brown and yellow around the outside.

Now we have to start over again! We will have to get another insect, put it in the trap and scan it again. Although this time we will scan it for a much shorter time - we have to learn from our mistakes!

P.S. You may have noticed the unusual background in the picture. This is because I went on holiday and didn't want to leave the flytrap on it's own in case it dried out, so it came with us! Here is a picture of it with some of our luggage in the back of the car. It is now very well travelled as came with us to Leeds and back!

X-raying the fly trap

Sharif put the fly trap in the X-ray machine for three hours to get a good image of the moth in the trap. We had to cut some of the stems and the flowers off so that the trap we wanted to scan was the tallest. We propped it up right using a straw and a piece of carbon rod.

Photos to follow...

The moths are ready

The moths have developed into adult moths. I met back up with Rob and we, well mainly he, grabbed a moth with some tweezers and put it in to one of the traps. The problem was that the moths were quite strong relative to the flytrap and held on to the tweezers so they didn't get trapped.

Here is a video showing the attempts made to put the moths in. In the first attempt the moth escaped, in the second if wasn't trapped by the fly trap. For the third attempt we had to kill the moth first and Rob dropped it into one of the traps. We couldn't keep trying because there were only a few traps that we would be able to scan as they have to be on long stems.

Thank you very much to Rob, who organise the moths for me, and Josh who filmed the video.

Now the moth is in the trap I will wait a few hours and pass it on to Sharif to scan it.

The fly trap is growing - part 3

Here is my second attempt at showing a time lapse of the Venous fly trap growing. Unfortunately the camera got moved so I've had to cut it short. You can see several shoots growing and a couple of the traps open at the back. At the bottom of the video you can see one the the traps turning black as it dies. The plant obviously doesn't need this one any more!

I also found this cool video by Manu Prakash from Cornell University on Youtube. It shows how they imaged how a fly feeds.

The flytrap is growing! - part 2

Here is the time lapse video I made of the Venus flytrap growing.

As you can see, it didn't really work. The stem that I focused on did nothing interesting and the shoots that did grow, grew towards the camera so didn't stay in focus! There are some interesting things happening, like the traps opening at the back and the shoots that grow upward together and then spring apart.

I have moved the camera to focus on another area of the plant. I hope this will make a better video.

How do we catch a fly - alive?

If I couldn't catch a fly I had to think of an alternative. Some people suggested I bought some maggots from a fishing shop and raised them to be flies, but I wasn't sure what sort of flies they would grow into or how I would catch them.

The solution was given to me by my friend Tom, who knew Robert who was working with moth larvae here at the University. I emailed him asking if they had any insects in their department that I would be able to use. We met up and Robert showed me some fruit flies that someone was using, which I thought would be too small and the moths that grew from his larvae, which looked about the right size. Here is a picture of one of the moths taken by Robert.

We must now wait until a larva grows into a moth and then we can feed it to the Venus flytrap!

The flytrap is growing!

A found on the flytrap that there was a new shoot growing! I have set up a webcam to take a picture every 48 minutes. I hope to make a time lapse of the shoot growing. Watch this space!

I also noticed that there are some very small traps and much bigger traps. In this picture you can see a small trap in the centre at the bottom and a much larger trap behind it. These traps could belong to separate plants.

How to keep the flytrap alive during the experiment?

In it's original pot the flytrap was too tall for the x-ray machine so we couldn't put the whole plant in. To solve this problem, I transferred the plant into a much shallower dish. I dug the plant out of the original pot by running a dinner knife around the edge. I carefully tipped the pot sideways until the plant began to slide out of the pot. The moss around the plant helped to hold the soil and plant together. The roots of the flytrap were very short and did not reach very far into the pot. I tipped the remaining soil from the terracotta pot into the shallow dish and then placed the flytrap on top. I gently patted the soil in around the plant.

Once the plant was in the new dish I carefully watered it. I have to add the water gradually now because the dish is so shallow it is very easy to pour on too much and then it flows over the edge of the dish making a lot of mess!

I hope the plant will survive the transfer to it's new home.

I cut a short piece from a drinking straw and placed it around one of the stems. This was quite a fiddly job. I had to be very careful not to damage the plant. I accidentally touched some of the traps near the base and they closed. They should open again in a few days when they realise they have been tricked! The drinking straw holds the stem up, keeping it vertical. This is not natural for the Venus flytrap but it will make it easier to x-ray an individual trap.

What settings should be used on the x-ray machine?

The flytrap that Julia gave me had some traps that were already closed. Sharif and I decided to carry out a test scan with one of these to find out what settings the x-ray machine needed and what we would be able to see.

In the x-ray machine you have to place the sample, the thing you want to x-ray, on a stage. Our first problem was that the pot containing the flytrap was too tall. The stage could not be lowered enough to get the leaves the flytrap in front of the x-ray source (this is where the x-rays are shot out from towards the sample).

As a solution, I cut off a trap that had caught a fly. We could see one of the wings sticking out of the top! Sharif placed the stem inside a short piece of a drinking straw and carefully packed in some oasis. Oasis is a foam which holds water, it is used by flower arrangers. It would help to keep the stem still while it was being x-rayed.

Sharif placed the straw in a sample holder and put it in the machine. It was now the right height. Sharif set up the machine and scanned the sample. Although this will give us an image to look at, the trap I cut off will die, so we won't be able to use it again.

Now we have to wait for the results. We also have to work out how we can put the whole plant in the scanner so we don't have to cut off a stem to put it in the x-ray machine and keep it alive so we can scan it multiple times.

How does the flytrap catch a fly?

An internet search revealed the fascinating way in which the Venus flytrap catches flies. There is a brilliant video from the BBC which explains it really well.

The inside of the leaves of the flytrap secrete a sweet nectar to attract insects. They also have a few trigger hairs. When the fly comes along to drink the tasty nectar it touches the trigger hairs. The trap won't shut if the fly only touches one of the hairs, the trap doesn't want to react to a false alarm, but if the fly touches two of the hairs, one after the other within a certain period of time, the trap snaps shut. The hairs that grow around the edges of the flytrap leaves are called cilia and these interlock together forming prison bars to stop the fly escaping.

After reading this, I was curious to know what killed the fly. Was it suffocated by the plant and then eaten? Or did the digestive juices get to it first - was it eaten alive?

http://www.livescience.com/15910-venus-flytrap-carnivorous.html
http://phys.org/news/2007-04-easy-oxygen-bug-life-full.html

How often should we scan the flytrap?

To find out how often we should scan the flytrap we needed to know how long it took for it to digest a fly. A quick internet search found many helpful websites about Venus flytraps. I have put a few links at the bottom of this post.

A flytrap digests a fly in 5-12 days. This gives us a range but we don't know exactly how long it will take in our case. We decided to scan the flytrap every 3 days after it trapped the fly until the trap opened again. If the flytrap digested the fly quickly, e.g. in 5 days, this means we would have a scan half way through the digestion process.

http://www.livescience.com/15910-venus-flytrap-carnivorous.html
https://www.flytrapcare.com/
http://www.bbc.co.uk/nature/life/Venus_Flytrap
http://science.howstuffworks.com/life/botany/venus-flytrap4.htm

How do we keep the flytrap alive before our experiment?

When I got the Venus flytrap to University I put it on the window sill next to my desk. I have a nice big window, so I hope the plant will get a lot of sunshine. Recently, the weather has been pretty bad with lots of cloud, but the flytrap still seems to be doing well.

At home, I put a bucket outside the back door of my flat. It will catch rain water and then I can use it to water the flytrap.

Where can we get a flytrap from?

The first thing we needed to set up our experiment was a Venus flytrap plant. My friend Julia has a large Venus flytrap in her conservatory. One day, when she was weeding it, she accidently pulled out some smaller plants from the mother plant. She put two into tea cups and one into a small terracotta pot to see if they would survive. The mother plant and the three babies can be seen in the picture.

The baby plants lived and Julia kindly gave me the one in the terracotta pot for our experiment. She gave me three very important instructions:

1. Always keep it wet - in the wild, flytraps grow in bogs, which are very wet environments
2. Only water it with rain water - nothing else!
3. Put it in the sunniest place possible.

Venus flytrap

The Venus flytrap turns the food chain on it's head. Rather than it being eaten by animals, it dines on unfortunate insects. After a flytrap has digested a fly, the trap opens to allow the exoskeleton to be blown or washed away. Here is a picture of the trap after it has opened. You can see the exoskeleton of the fly. It doesn't look that much different to a live fly. It just looks like it has been squashed.

Sharif and I thought it would be cool to see what happens to a fly as it is digested by the fly trap. We can do this using x-rays to see through the trap when it is closed.

We made a plan for our experiment:

1. Get a Venus flytrap
2. Get a fly
3. Put the fly in the flytrap
4. Take an x-ray scan at just after it have caught the fly
5. Take more x-ray scans every few days to see what changed

Sharif and I realised that we needed to know a few things before we could carry out our experiment of a Venus flytrap digesting a fly. We made a list of questions:

• Where can we get a flytrap from?
• How do we catch a fly - alive?
• How do we keep the flytrap alive before and during our experiment?
• How often should we scan the flytrap?
• How does the flytrap catch a fly?
• What settings should be used on the x-ray machine?
• Would x-raying the flytrap kill it?
• Why does the flytrap need to eat flies?

Time to go and do some research!