# Fruit fly media experimentation.



## Jason (Oct 14, 2004)

A few months ago I posted about the use of cinnamon in fruit fly cultures.
http://www.dendroboard.com/forum/food-feeding/31886-what-do-mummies-plastic-wrap-have-common.html
The reason why is because cinnamon is known to inhibit mold. When I started the experimentation I had no frogs, so it didn't matter if the culture crashed.

Here is my 1st experiment.

I wanted to know if the cinnamon would reduce the fruit fly production. I used the same media mixture, but added various amounts of cinnamon. 

My media is:
6 cups potato flakes
1 cup powdered sugar
1/2 cup brewers yeast.
Mix 1/2 cup of dry mixture and add 2/3 cup of 50/50 vinegar/water. The vinegar is used to inhibit mold and since I was only testing for fruit fly production I stuck with a recipe I know works to produce flies and inhibit mold.

This was done using Drosophila melanogastor fruit flies. Cultures were made on 10/09/2008 and temps were kept between 70 to 73 degrees. 










The cup on the left was the control and contained NO cinnamon, Middle cup contained 1/4 teaspoon, Right cup contained 1/2 teaspoon. As you can see there seemed to be no reduction in fruit fly production due to the cinnamon.

My next experiment will involve just using water and no vinegar to test how well cinnamon can control mold.


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## kristy55303 (Apr 27, 2008)

scientist in the making. great post. gonna try a honey experiment? kristy


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## porkchop (Aug 29, 2005)

Thanks Jason, I'll be watchin for results...


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## MonarchzMan (Oct 23, 2006)

No reduction? Before reading that, it looked like a nice negative correlation to cinnamon. Just looking at pupae production, the one with no cinnamon goes highest up the side of the cup. Mid cinnamon goes slightly lower, and high cinnamon is the lowest. That's just what the visual shows me. I can't tell on number of flies.

One thing also to consider that Drosophila aren't "fruit flies" but actually vinegar flies (I only know this because I worked with a grad student who was anal about that distinction), and I believe that the adults feed on the vinegar, so it'll be interesting if you get a lot or little production with no vinegar.

Just as an FYI, true fruit flies are actually in the family Tephritidae (Drosophila are in Drosophilidae). 

I'll be watching with rapt interest!


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## Ed (Sep 19, 2004)

While the fruit flies do ingest vinegar, they do not need vinegar..... nor is this really what they feed on.. (There are a lot of peer reviewed articles on thier nutritional needs.. for example see Nutritional Requirements of <i>Drosophila melanogaster</i> : Abstract : Nature or The Quantitative Nutritional Requirements of Drosophila Melanogaster -- SANG 33 (1): 45 -- Journal of Experimental Biology) Both the larva and adults feed on the slurry in the media and incidentally ingest alcohol and/or vinegar.. the main source of nutrition for the flies comes from the media, yeast, and bacteria (and with the larva even the dead carcasses of other larva and adults as they actively secrete chitinases) which they semidigest prior to feeding (the larva actively secrete digestive enzymes and the adults feed in the normal lap it up sort of feeding like house flies). It is also possible to raise the flies in sterile condition without any bacteria or yeasts at all in the flies or media without any vinegar or alcohol in the media. (for example see SpringerLink - Journal Article for a reference for raising yeast/bacteria free ffs on insect carcasses)

the main mold inhibitor of cinnamon is cinnamon oil (see 65C-26 Mold growth inhibition using cinnamon oil) and this is typically between 0.5 and 3% of the bark, and to get some level of mold inhibition you need close to 100 ppm of the essential oil however cinnamon oil has been shown to not only be toxic to insects (see http://www.banglajol.info/index.php/JBS/article/viewFile/441/456) but to inhibit thier feeding even in low concentrations. Now this is where it could be problematic for the culture as this could result in the production of ffs that are nutrient deficient.... 


There are a lot of different ways to try and avoid molding of the media and one of the simplest is to simply microwave them to sterilize the media. 

Some comments,

Ed


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## melissa68 (Feb 16, 2004)

We've missed you Ed!!!!

What do you think about using honey in cultures. We have been using it for years to help control smell. There are a lot of additional benefits to honey as well, but I don't have the grasp of science you do. Here is the post - http://www.dendroboard.com/forum/food-feeding/32919-containg-smell-ff-cultures.html#post294167 your thoughts?

Regarding cinnamon & Egyptian tombs - aren't there some other potentially toxic oils and stuff in there. I remember reading some articles & seeing some shows which describe everything covered in a reddish dust (not sand - but was part of the preservation process). Anyone care to chip in and explain some of the other things too.




Ed said:


> While the fruit flies do ingest vinegar, they do not need vinegar..... nor is this really what they feed on.. (There are a lot of peer reviewed articles on thier nutritional needs.. for example see Nutritional Requirements of <i>Drosophila melanogaster</i> : Abstract : Nature or The Quantitative Nutritional Requirements of Drosophila Melanogaster -- SANG 33 (1): 45 -- Journal of Experimental Biology) Both the larva and adults feed on the slurry in the media and incidentally ingest alcohol and/or vinegar.. the main source of nutrition for the flies comes from the media, yeast, and bacteria (and with the larva even the dead carcasses of other larva and adults as they actively secrete chitinases) which they semidigest prior to feeding (the larva actively secrete digestive enzymes and the adults feed in the normal lap it up sort of feeding like house flies). It is also possible to raise the flies in sterile condition without any bacteria or yeasts at all in the flies or media without any vinegar or alcohol in the media. (for example see SpringerLink - Journal Article for a reference for raising yeast/bacteria free ffs on insect carcasses)
> 
> the main mold inhibitor of cinnamon is cinnamon oil (see 65C-26 Mold growth inhibition using cinnamon oil) and this is typically between 0.5 and 3% of the bark, and to get some level of mold inhibition you need close to 100 ppm of the essential oil however cinnamon oil has been shown to not only be toxic to insects (see http://www.banglajol.info/index.php/JBS/article/viewFile/441/456) but to inhibit thier feeding even in low concentrations. Now this is where it could be problematic for the culture as this could result in the production of ffs that are nutrient deficient....
> 
> ...


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## Ed (Sep 19, 2004)

Hi Melissa,

Honey shouldn't negatively affect ff production or inhibit feeding unless the concentration is too high (changing the osmotic potential of the media but this is unlikely) as honey water has been used as a insect food source for a long time (primarily with ants, bees and wasps).. additionally the yeast in the media can use the honey as a food source (and probably target it very early on in the process) (a yeast fermented honey drink called mead/honey wine has been around for a really long time...) If you use dried honey does it still prevent the smell? 

With most cases, foul smells are probably due to other colonizing bacteria which can be prevented, eliminated via pasturizing the media and then cooling it covered until it is seeded with an active yeast culture. Without an analysis, the foul smells are probably due to anaerobic breakdown of the protiens in the media... I am still on a relatively small scale here so I can microwave my cultures which seems to prevent it from happening for me.. 
Some comments, 

Ed


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## Jason (Oct 14, 2004)

MonarchzMan said:


> No reduction? Before reading that, it looked like a nice negative correlation to cinnamon. Just looking at pupae production, the one with no cinnamon goes highest up the side of the cup. Mid cinnamon goes slightly lower, and high cinnamon is the lowest. That's just what the visual shows me. I can't tell on number of flies.


Yea, it was a bad picture I admit. I could turn the containers 180 deg and you would see something completely different. I thought there would be a huge noticeable difference, but it didn't appear to be.



Ed said:


> While the fruit flies do ingest vinegar, they do not need vinegar..... nor is this really what they feed on.. (There are a lot of peer reviewed articles on thier nutritional needs.. for example see Nutritional Requirements of <i>Drosophila melanogaster</i> : Abstract : Nature or The Quantitative Nutritional Requirements of Drosophila Melanogaster -- SANG 33 (1): 45 -- Journal of Experimental Biology) Both the larva and adults feed on the slurry in the media and incidentally ingest alcohol and/or vinegar.. the main source of nutrition for the flies comes from the media, yeast, and bacteria (and with the larva even the dead carcasses of other larva and adults as they actively secrete chitinases) which they semidigest prior to feeding (the larva actively secrete digestive enzymes and the adults feed in the normal lap it up sort of feeding like house flies). It is also possible to raise the flies in sterile condition without any bacteria or yeasts at all in the flies or media without any vinegar or alcohol in the media. (for example see SpringerLink - Journal Article for a reference for raising yeast/bacteria free ffs on insect carcasses)
> 
> the main mold inhibitor of cinnamon is cinnamon oil (see 65C-26 Mold growth inhibition using cinnamon oil) and this is typically between 0.5 and 3% of the bark, and to get some level of mold inhibition you need close to 100 ppm of the essential oil however cinnamon oil has been shown to not only be toxic to insects (see http://www.banglajol.info/index.php/JBS/article/viewFile/441/456) but to inhibit thier feeding even in low concentrations. Now this is where it could be problematic for the culture as this could result in the production of ffs that are nutrient deficient....
> 
> ...


I love your posts, very informative. Yea, the food industry is using cinnamon oil in the packaging to prevent mold in bread for instance. There was also a study done that used ground cinnamon just using some quick googleing I found. Antimicrobials in Food - Google Book Search

I figured what the hell lets give it a shot. If it negatively affects the nutrition of the FF themselves than it is a bust for sure.



melissa68 said:


> We've missed you Ed!!!!
> 
> What do you think about using honey in cultures. We have been using it for years to help control smell.


I normally use honey as well, but did not for this experiment. I have never had a problem with mold using the 50/50 vinegar/water with a little honey, but again I was just messing around and wanted to see what cinnamon would do.


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## Ed (Sep 19, 2004)

Jason said:


> Ye=2&ct=result#PRA1-PA437,M1]
> 
> I figured what the hell lets give it a shot. If it negatively affects the nutrition of the FF themselves than it is a bust for sure.


Hi Jason,

I had been meaning to look into the cinnamon thing earlier as one of the flavoring agents is eugenol which has been shown to have some toxic properties. I just hadn't gotten around to it with one thing or another happening but amphibian nutrition is one of those things I am pretty interested in following. 

My main concern with the decrease in feeding is that the flies could be deficient in some nutrients which the supplements would not be able to correct. 

Ed


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## Jason (Oct 14, 2004)

Ed said:


> Hi Jason,
> 
> I had been meaning to look into the cinnamon thing earlier as one of the flavoring agents is eugenol which has been shown to have some toxic properties. I just hadn't gotten around to it with one thing or another happening but amphibian nutrition is one of those things I am pretty interested in following.
> 
> ...


Good to know. I will hold off on feeding any flies from this to my frogs I picked up at MWFF. This would be important information to know because I believe "what others have said" that some of the commercial FF mixes out there may contain cinnamon.


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