Effects of Herbal Tea on Fruit Flies

[Aly308]

I have recently been researching some science experiments involving fruit flies. I have a couple questions.

I found an experiment that tested if different types of herbal teas made fruit flies live longer.

Question 1) When I have a conclusion to my experiment, is it ok to claim that the same results will work on humans, or simply imply that notion?
Question 2) I found the experiment online. It has already been done, but I'm and thinking of using different types of teas, and possibly coming up with a different or variant conclusion. Is this ok, or should I try and think of my own experiment?

Thank you so much for the help.

-Aly

[donnahardy2]

Hi Aly,

Hi,

With a science project, you want a project that is unique and a reason for doing it. Testing the effect of herbal teas on the lifespan of fruit flies is a very worthwhile subject and you should be able to design an experiment that is different than experiments done before. For example, be sure to include enough flies so that you can calculate the statistical significance of your results. Plan to do the experiment twice. Use different teas. Control all other parameters more carefully. I’m sure there is something you could do to improve the experimental design.

The conclusions for your project would apply only to fruit flies; you could not claim that any effect on humans. You would need to be careful and make sure that the analysis of your results reflected the actual data. However, you could include a discussion on the possible relationship between fruit fly and human longevity and you could suggest additional research ideas

Since you are just getting started, be sure to read through the Science Fair Project Guide on the Science Buddies website. You may find that doing additional background reading on this topic will help you design a unique experiment.

https://www.sciencebuddies.org/science- ... ndex.shtml

Donna Hardy

[Aly308]

Donna, Thanks for the link, it was really helpful.

To make my project accurate, I'm going to need at least 100 fruit flies. My main concern about catching them outside using fruit as bait is that I will accidentally catch other insects as well as the fruit flies. I've looked online, and have found some eggs that I can buy, but they take 4-8 weeks to hatch. Do you have any recommendations?

Also; Big question: How in the world am I going to count the fruit flies. I guess I'll need to see which herbal teas increase their life span the longest. But how am I going to count how many I are alive?

Thanks again, Donna!

-Aly

[donnahardy2]

Hi Aly,

What is the ambient temperature where you live? If the temperature is 20 degrees Centigrade or higher, you don’t have to capture flies in the wild and it won’t take 4-8 weeks for the eggs to hatch. Just leave a piece of fruit that is damaged or starting to rot outside and you will have hundreds of wild type red-eyed fruit flies within a week or two. You will need an enclosed container to contain the flies once they hatch. To avoid complaints from family members during this project, you might consider ordering a culture of wingless fruit flies. Here is some information on culturing fruit flies.

http://www.joshsfrogs.com/catalog/blog/ ... uit-flies/

Learning how to raise and care for your fruit flies is going to be an important part of this project.

It’s good that you are thinking about the logistics of actually doing the experiment. While you are waiting for the first group of eggs to hatch, do consider how you are going to take care of the flies during the experiment. I don’t think you could work with 100 at one time; you’d need to work with smaller groups. It would probably be better to allow 10-20 eggs to hatch inside a container and then remove the remaining unhatched eggs so all flies in the container would be zero days old at the beginning of the experiment. You would then need to be able to add food and tea without allowing any flies to escape or drown. You would count the flies in each container every day for about 30-40 days until no flies are left alive. I would recommend doing a small pilot experiment to start with to allow you to optimize the experimental protocol; you could then set up the definitive experiment with 100 flies in each group.

You will need to control all parameters except the tea. What conditions are important to control in this experiment?

Donna

[Aly308]

Donna,

Thanks for your help! I really appreciate the time you have put into helping me with my project!

I have a couple more questions. When I do do the definitive experiment, how will I count the flies as they began to lay eggs and multiply?
Also, I think that at this point it would be more reasonable for me to use the idea you had about using fruit as bait to catch flies in the wild. Is this as accurate as ordering eggs, or should just order the eggs first?

Thanks!

Aly

[donnahardy2]

Hi Aly,

With this type of experiment, you need to start each group of flies in an enclosed container on the day they emerge from the puparium. You will need a control (no tea) group every time you set up an experiment. You need to keep the density of flies, the temperature, the food, the light, and all other environmental conditions constant throughout the experiment. It will be important not to provide an opportunity for new eggs to be laid and hatched during an experiment, otherwise you won’t know how long each individual fly survives. Ideally, you will start each group of flies in an enclosed container and provide them with ideal living conditions, and then count them periodically until there are no survivors.

The type of fly used in your experiment is another parameter that you can control. You can either order a specific strain of fruit fly and get a colony started, or set out a piece of mashed banana, strawberry, tomato or other fruit and start a colony of local wild fruit flies. If the temperature is over 65 degrees Fahrenheit where you live, you will have a large family of fruit flies within a few days. If you do decide to order fruit flies, then selecting a strain that does not fly would probably make counting the flies a little easier. But you would have to plan to maintain the purchased fruit fly colony until the end of your experiment, and make sure that wild type fruit flies don’t invade your colony. Any type of fruit fly would work well for this experiment. It’s your decision to make.

The logistics of this experiment will be challenging and that’s why the pilot experiment is very important. If you set up just a couple of control containers, you will gain valuable experience in the logistics of the experiment and figure out what you need to change for the final experiment.

What do you plan to house your flies in? Are you going to build something?
What are you going to measure other than numbers of surviving fruit flies? I would recommend monitoring the temperature at a minimum. How are you going to measure the dose of tea in the experimental group? How will you make sure the flies consume the tea? What will the control flies have instead of tea?

Before you start, it will be helpful to write a detailed experimental protocol. This will help you think of all of the details. Here's the guide from the Science Buddies Website:

https://www.sciencebuddies.org/science- ... dure.shtml


Donna Hardy

[Aly308]

Donna,

Thanks for the website, I sort of had a general idea of the procedure, but the link helped me organize my ideas.

I have made some control traps already. I'm using two large jars, with banana peels in each, and I have some Saran wrap with holes pocked into it on the mouth of the jar. I was wondering how I could control the egg laying of the fruit flies if I caught wild fruit flies. How will I ensure that they don't lay eggs? Do you think it would be more sensible for me to order the fruit flies so that I can be absolutely positive that the fruit flies are all the same age?

My control flies will have distilled water, and I'm thinking of buying some fruit-fly food(food created only for fruit flies) and putting it into the tea and water.

Thanks,

Aly

[donnahardy2]

Hi Aly,

Here is a website that includes two fruit fly recipes that include water. You could use tea for the water for your experimental groups. I would recommend that you use homemade food (always using the same recipe) rather than purchased food. You are going to need a lot of fruit fly food for this project. You can probably prepare a batch of fruit fly food once a week and store the supply in the refrigerator.

http://www.livefoodcultures.com/FruitFlyFood.html

You need a standardized way to make the tea for each group, and some way to measure the concentration of the tea.

To keep new flies from hatching inside your control and experimental fly chambers, you will probably need to add new food and completely remove the old food every day. Fruit flies can mate within 12 hours of emerging from the puparium and eggs can hatch within 12 hours, so maintaining fresh food will be essential to make sure no new flies emerge after you have started the experiment.

Do you have any fruit flies in your banana peel traps yet?

Donna

[donnahardy2]

Hi Aly,

One more question. Which herbal teas are you planning to use? Have you found any background research showing a correlation between the chemicals found in herbal teas and longevity? This information would help support your reason for doing the project, and help you design a unique project.

Donna

[Aly308]

Hi Donna,

I have a couple herbal teas I'm considering; Green Tea, Valerian Tea, possibly peppermint tea. I know green tea is really big for living longer, and Valerian can calm you down... I've done some research on the teas I'm going to use.

I was wondering what the best way to replace the food would be. I know I have a lot of questions!

Also, no fruit flies in either banana peel traps yet. Hopefully they should accumulate within a day or two.

Again, thank you for helping!

Aly

[donnahardy2]

Hi Aly,

You are welcome! It’s very good to try and think of all of your questions at this stage of your project to ensure having the best possible outcome with your experiments.

Do you have anyone available who can advise you on a construction project? You are going to need multiple fruit fly chambers. If you start with 25 flies in each chamber, for example, then you will need 4 chambers for the control group and 4 each for each tea you test. You can’t open a chamber to the open air; otherwise your test subjects will fly away. I think the best approach would be a double door approach; with an inside door that you can close while you are changing the food. A slot covered by a curtain that would drop immediately as the food dish it is removed or replaced might work also... Designing a suitable chamber will be an important part of this project. What are you going to use for food dishes? You need something that absolutely will not spill, or, if it does, a way to clean it up.

Green tea is a good choice, because it looks like there has been some research done on this tea. Here us a non-scientific website that reports the results of a study on green tea drinkers in Japan over an 11 year time span. Green tea drinkers were found to have a 31% lower risk for death due to cardiovascular disease, but there was no difference in deaths due to cancer. You should try to get the original reference that was published in the scientific journal.

http://www.futurepundit.com/archives/003719.html

You should do an internet search and try to find the original research articles on this subject and compile these in a bibliography. Try to find as much information that has been learned in scientific studies. The problem with searching for information on herbal teas is that almost all of the websites are not based on scientific research.

You also need to find out about the chemical composition of the teas. Here is an abstract from a scientific publication reporting the composition of green tea. You can also do a search on the individual components of green tea (epicatechin 3-gallate, caffeine), to learn more about the chemistry of the tea. Have you had chemistry yet? Let me know if you can understand this.

http://www.ncbi.nlm.nih.gov/pubmed/17899383

I could not find any research reports on valerian and lifespan, but you should look and see if you can find some information. Here is an example of a non-scientific website that promotes the use of Valerian. The information sounds good, but there is no scientific basis for the information. Definitely avoid using this type of website in your bibliography.

http://www.vrp.com/heart-health/stress- ... -longevity

Here is a website for a Professor of Nursing at Penn State Nursing School. She is doing research on Valerian, so you can send her an e-mail (with your parent’s permission) and ask her for additional information on this topic.

http://www.nursing.upenn.edu/faculty/pr ... p?pid=1123

The Wikipedia website on Valerian includes a summary of its chemical composition and also includes some scientific sources in the bibliography. Read as much as you can about the physiological effect of each of the components and try to decide if you think Valerian will increase the lifespan of fruit flies. For example, do you think the alkaloids will relax the fruit flies and make them mellow so they will live longer or maybe put them to sleep prematurely? Be sure to check out the Gamma-amino butyric acid. Incidentally, I think that Valerian is a very good choice for your science project because most of the research on this herb has been done on its sedative and pain reliever effects, and so research on lifespan definitely needs to be done.

http://en.wikipedia.org/wiki/Valerian_(herb)

Please let me know what you find out about your topic. I recommend printing out all of your literature sources and putting them in a 3-ring binder so you will have easy access to the information when you are writing your background research. You will also need to refer to the articles later when you are trying to explain your results.

Where are you going to purchase your tea? You need to check with the supplier and make sure you don’t use any product that contains pesticides or heavy metals. Contaminants like this could kill off your flies prematurely.

Can you confirm that your ambient temperature is above 65 degrees F? Are your banana peel traps in a quiet, shady location with no wind? Are they moist enough? Something is wrong because fruit flies typically appear out of nowhere if a piece of fermenting fruit is available. I recommend resetting your traps if you don’t see hovering flies with red eyes by tomorrow.

Donna

[Aly308]

Hi Donna,

Thanks for all the websites. I'll look into all of them.

About the traps: I think it is a great idea to make the traps so I can ensure no flies will lay eggs. Perhaps I can catch my flies in the simple traps, and transport them into the more advanced traps once I've gotten the appropriate amount of flies for the project.

No fruit flies in my traps yet. I have a screened in porch on the back of my house, and the screen door is always kept open. I've put the traps on the porch, but now that I think about it, it would be better to move them to a more open area so the flies will have better access to the rotting fruit. The predominant temperature in my area in the summer usually stays around 27 centigrade, so I should be good temperature-wise. It also very humid where I live.. I don't know if this will affect anything or not.

I'll see how things go, and print out those links that you mentioned. Thanks again, Donna!

If I have any more questions I'll post them!

[donnahardy2]

Hi Aly,

Your climate conditions are ideal for fruit flies. I can't believe you don't have any. Placing the traps outside near garbage cans or near a fruit tree with fruit on the ground should solve the problem. You might find some inside if you have a bowl of fruit inside with some older fruit in it. You are going to have a very successful experiment once you have some flies with an average temperature of 27 degrees Centigrade.

I don't know how you will design a chamber that would allow the flies access to their food, but not allow them to lay eggs in it. But that's why you need to do a pilot experiment.


Donna

[Aly308]

Hi Donna,

I have moved my traps outside, but I know have an infestation of ants in my traps. I may end up using ants, because I know they don't reproduce as quickly.

I have come with a model trap that would prevent fruit flies from laying eggs.

[donnahardy2]

Hi Aly,

The fruit flies are perfect for your science project because you can watch the flies emerge from the puparium to start the experiment at time 0, and the flies live for about 30 days, which is perfect for your time frame. So don't switch to ants unless you pick a different project. The ants will probably inhibit any fruit flies, so put the base of your traps in a saucer of water and make sure the fruit/banana peels are fermenting. Fruit flies prefer rotting fruit.

Donna

[donnahardy2]

Hi Aly,

How are your Drosophila traps? If you don’t have any small red-eyed flies in your traps yet, then you should consider ordering them. You could also do a search of your neighborhood and look for any fruit trees with dropped fruit on the ground, or perhaps a bed of strawberry plants with some older fruit that has not been picked.

Here’s more information for your background reading.


Here is some information from a scientific reference on the health benefits of peppermint tea. The paper includes the names of the compounds found in the tea and the physiological effects, although it is not apparent if any of the effects are related to lifespan. The e-mail address of the author is included. http://www.ncbi.nlm.nih.gov/pubmed/16767798

And here is a reference that you can use to make the connection between lifespan of Drosophila and humans. It turns out that Drosophila melanogaster is one of the model organisms used for studying the biology of aging. It would be worthwhile to try to get a copy of this paper because it reviews the age-relating declines in Drosophila and the corresponding correlation to human decline.

http://www.ncbi.nlm.nih.gov/pubmed/16024299

Donna Hardy

[donnahardy2]

Hi Aly,

Are you making any progress on your project? Do you have any fruit flies to work with yet?

Donna