# hydei all dead



## Rain_Frog (Apr 27, 2004)

Okay, I setup a fresh culture of hydei and then within a few days, they were all dead. I mixed old flies and new flies. Any idea what happened? Perhaps too much yeast? I am using a recommended media.


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## Philsuma (Jul 18, 2006)

Going on 6 years of fly production and I *still* cannot get hydei "right" 

I've all but given up on them.


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## JoshK (Jan 5, 2009)

What kind of yeast do you think you added too much of? Since I stopped adding bakers yeast to my Hydei, my cultures have been MUCH more stable. I've also done some experimenting with the brewers yeast and I don't think it is possible to add to much as long as you keep it wet enough.


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## Rain_Frog (Apr 27, 2004)

I think I put too much baker's yeast on the cultures.


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## Zombie Frawg (Aug 31, 2010)

I'm super thankful that I have not had problems with my Hydei cultures, especially since I bought the first one by accident! I wish I could tell you what I do to make it work but I really don't know. I've just been setting them up the same as my melano's and haven't had any issues. Actually they are booming, I can't feed them off fast enough.


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## guppygal (Aug 23, 2007)

I agree with Josh - my Hydei are booming since I upped the brewer's yeast. I've had Hydei cultures fail before and it was because I didn't wait a couple of days after adding baker's yeast and the liquid. Now, I've got more Hydei than I can handle, they're breeding so fast...

kristi


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## Rain_Frog (Apr 27, 2004)

> I've had Hydei cultures fail before and it was because I didn't wait a couple of days after adding baker's yeast and the liquid.


So, you don't add bakers yeast for a few days? What liquid are you talking about?


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## Zombie Frawg (Aug 31, 2010)

Forgive my ignorance, but what is the purpose of the yeast? I've never added it to my cultures.


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## Rain_Frog (Apr 27, 2004)

baker's yeast is what the adult flies eat. But, adult flies can often carry yeast spores on their bodies.


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## TDK (Oct 6, 2007)

I've always used baker's yeast in my hydei but I'll try it woithout next time to see what results I get.


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## stemcellular (Jun 26, 2008)

I use just a pinch of yeast and have never had a problem with hydei.


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## guppygal (Aug 23, 2007)

I think there'is an issue with the carbon dioxide emitted by the yeast in the first day or two after the liquid is mixed with the dry ingredients. Different folks prep their cultures different ways, so this might not apply here. I use the potato flakes/powdered sugar/brewer's yeast recipe mixed with half water/half vinegar, 1:1 ratio. I put a pinch of baker's yeast on top after I add the liquid just because someone told me to. I don't know if it makes a difference whether it's there or not, but on the occasions where I've added my flies immediately after the yeast, the cultures died. It took me a couple of times to figure out what I was doing wrong.

This time around, when I prepped my dry ingredients, I added almost double the brewer's yeast, and my Hydei just went nuts! Had I known that this one lil ingredient made all the difference in the world.....and waiting a couple days before adding the flies, of course.

Hope that helps -

kristi


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## Rain_Frog (Apr 27, 2004)

interesting. Usually, I add flies within a few days just because I forget. These two cultures I added hydei within a day. I've never had issues with melanogaster though-- adding flies once the mixture was cooled.


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## guppygal (Aug 23, 2007)

It's a theory that might be worth testing. Since I've got so many Hydei, I'll prep a couple of cultures and add flies immediately to one, and wait a couple of days on the other.

Let's see what happens ~


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## RentaPig311 (Jul 6, 2009)

Love the idea of a test guppy girl. I've had tons of trouble with my hydi and for some reason this last batch really took off. I did forget about it and added flies a few days later so maybe that's the key. I use a store bought mix and a pinch of yeast on top.


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## zBrinks (Jul 16, 2006)

One thing to keep in mind - due to the life cycle of hydei, it is not uncommon for most/all of the adult flies to die off before new flies emerge. Half the time people talk to me about hydei cultures crashing, this is what has happened.


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## BlueRidge (Jun 12, 2010)

I was always told to only use 2-3 grains of yeast after the culture has cooled. Too much will kill off the flies.


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## guppygal (Aug 23, 2007)

Okay, I've got 3 test bottles set up:
bottle 1 - fresh culture, added liquid, added baker's yeast, added Hydei
bottle 2 - fresh culture, added liquid, added Hydei - no baker's yeast
bottle 3 - fresh culture, added liquid, added baker's yeast, will add Hydei in two days

All Hydei come from the same previous culture -

I'll keep y'all posted -


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## Ed (Sep 19, 2004)

guppygal said:


> I think there'is an issue with the carbon dioxide emitted by the yeast in the first day or two after the liquid is mixed with the dry ingredients. Different folks prep their cultures different ways, so this might not apply here. I use the potato flakes/powdered sugar/brewer's yeast recipe mixed with half water/half vinegar, 1:1 ratio. I put a pinch of baker's yeast on top after I add the liquid just because someone told me to. I don't know if it makes a difference whether it's there or not, but on the occasions where I've added my flies immediately after the yeast, the cultures died. It took me a couple of times to figure out what I was doing wrong.
> 
> This time around, when I prepped my dry ingredients, I added almost double the brewer's yeast, and my Hydei just went nuts! Had I known that this one lil ingredient made all the difference in the world.....and waiting a couple days before adding the flies, of course.
> 
> ...


Why are you assuming that there is a difference in carbon dioxide production on days one and two and not on later dates in the culture? The yeast are going to continue to function until either the alcohol content or vinegar content gets high enough to shut down production but this does not mean that CO2 production is reduced as other microbes take over (including the ones that convert ethanol to acetic acid).. microbial production of CO2 is unlikely to decrease for a couple of weeks or more.. 

One of the most common problems when attempting to culture hydei is that there is difference in emergence of males and femals in hydei and if you use mainly flies from the first emergence you will seed the culture with females that are too young to have mated and the newly emerged males take around a week to become sexually mature. see Drosophila hydei). This problem is where I think most people have problems with hydei as they are throwing away cultures at 30 days to avoid mites and this means that the mature males are also being discarded. 

Ed


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## guppygal (Aug 23, 2007)

About how long does a sexually immature female Hydei live? A couple of days? If that's the case, then of course, your explanation makes perfect sense. 

I'm one of those folks who keep cultures around for 2-3 months, then hand 'em over to the frogs. Like Rain Frog, though, I've lost cultures within a few days after adding flies immediately after prepping the culture.

BUT, I read in another post from a few months back about the Co2 and that's why I brought it up again. I thought I might test it to verify, and I'm using an older culture of flies. Here's the link in case you want to review : http://www.dendroboard.com/forum/food-feeding/54679-power-mix-ff-culture-kills-my-ff-2.html

Let's see what happens with my little test - who knows, we might learn something....or not.

kristi


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## Ed (Sep 19, 2004)

guppygal said:


> About how long does a sexually immature female Hydei live? A couple of days? If that's the case, then of course, your explanation makes perfect sense.
> 
> I'm one of those folks who keep cultures around for 2-3 months, then hand 'em over to the frogs. Like Rain Frog, though, I've lost cultures within a few days after adding flies immediately after prepping the culture.
> 
> ...


Except your test does not prove that CO2 produced by yeast is the problem... you are theorizing that CO2 production by yeast is the problem and you have no way to quantify whether it was due to the yeast, or other microbial contaminents... Your test is assuming that yeast are the only microbial source of CO2, this is not the case. To do this properly, you would need to use flies that were raised in a sterile enviroment to prevent contaminents, sterile cultures so you can claim that only yeast was growing in it..and controls with non-sterile flies and non-sterile media. As a further issue, if you are trying to show that it was the problem with Rainfrog's flies, you would need his flies.. 

In culturing flies, the addition of baker's yeast is to reduce the chance of a contaminent as the microbes that are being carried on the flies are much more adapted to your personal culture conditions and are going to be much more efficient at colonizing the media (in conjuction with the stirring of the media and excretion of digestive enzymes by the larva). 
As a further problem with the test, how are you determining that air exchange is equivalent between all three "tests"? 

CO2 is heavier than air, if there was sufficient levels of CO2 to kill the flies, you would see deaths in all of the trials (and whether the flies were added on day one or day three) unless you were aerating the cultures. . That is one of the parts of the problem with assuming that the CO2 production on day one or two is the problem....

And it isn't my theory on the problems with Hydei culturing. The problem with hydei emergence and problems with culturing has been documented in the hobby literature for decades.. 

Ed


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## guppygal (Aug 23, 2007)

Good grief, Ed - it's just a simple theory and a simple test - heck, I didn't even wash my hands before I put 'em together..... 

Let's see what happens - odds are, I'm way off base......


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## Ed (Sep 19, 2004)

guppygal said:


> Good grief, Ed - it's just a simple theory and a simple test - heck, I didn't even wash my hands before I put 'em together.....
> 
> Let's see what happens - odds are, I'm way off base......


I'm pointing out the problem as I've been around long enough to see how these sorts of results can be blown well out of proportion and hang around for years.... and I can cite examples... 

Ed


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## RentaPig311 (Jul 6, 2009)

As a simpleton I'm still interested in the test. I would just switch back to melo but I kinda feel bad for the frogs having to chase down so many.


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## Ed (Sep 19, 2004)

RentaPig311 said:


> As a simpleton I'm still interested in the test. I would just switch back to melo but I kinda feel bad for the frogs having to chase down so many.


I have two words for you.. Bean Beetles.. they are very close in size to hydei, and are much much easier to produce and the frogs do very well with them.. 

Ed


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## guppygal (Aug 23, 2007)

I've been feeding Hydei exclusively for 7 yrs - I just now added mels for my newly morphed auratus froglet and my imitators. It drives me nuts when those tiny flies start using their darn wings....

k


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## froggiesrule (Oct 8, 2010)

I like rice flour beetles better then bean beetles..... I hated running to 5 different stores asking for "black eyed peas" or other strange beans and having the owner stare at me like I had 2 heads


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## Philsuma (Jul 18, 2006)

froggiesrule said:


> I like rice flour beetles better then bean beetles..... I hated running to 5 different stores asking for "black eyed peas" or other strange beans and having the owner stare at me like I had 2 heads


Wow...where do you live? Black eyed peas are found at just about every single grocery store in every state I've been in.

BB are 100 times easier to culture, keep going and feed out than rice flour beetles AND just about everybody eats them. Rice flour beetles must have some bad taste - a lot of frogs refuse them and even the larvae...


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## alex111683 (Sep 11, 2010)

I am subscribing to this thread. I would love to see what your results are guppygal.


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## Zombie Frawg (Aug 31, 2010)

I have to agree with Ed. He got me on the Bean Beetles and my leucs love them. I still culture melano's and hydei for variety. The only issue I have with the Bean Beetles is they get out of the viv and I find them all over. Usually when I'm on the computer, they go walking across the screen.


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## Rain_Frog (Apr 27, 2004)

If CO2 isn't an issue-- and I mixed old flies with new flies-- what could have caused the death of the hydei?


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## Ed (Sep 19, 2004)

Rain_Frog said:


> If CO2 isn't an issue-- and I mixed old flies with new flies-- what could have caused the death of the hydei?


I am going to run down a list of possible items... 

1) Old and new flies does not mean that there was a mixture of sexes as each emergence from the pupae follows the same pattern. If you had fed out from the older culture you could have wiped out all of the available breeders. 

2) CO2, unlikely as Drosphilia show adaptions to survive low O2 enviroments (and some strains can survive conditions that have an oxygen content as low as 4% O2 (while normal atmosphere is around @21%). Now depending on your culture systems and the background of the flies, as with many other things, you can select flies that are very intolerant of lower oxygen levels (but you should see them clustering around the top of the container to get to the higher O2 levels).

3) microbial contamination killed the flies. The flies are susceptiable to a number of microbial pathogens including Wolbachia (which is known to occur in cultured fruitflies) see Wolbachia, normally a symbiont of Drosophila, can be virulent, causing degeneration and early?death ? PNAS 

4) condensation. If the media was heated and not totally cooled, residual heat from the media increases heat and condensation on the sides of the culture container trapping and drowing the flies. Or the surface of the media may have been too damp trapping the adult flies. 

5) excess heat from media if it was heated and not totally cooled. In a closed culture cup temperatures can reach lethal levels for the flies fairly easily. 

Those are possible issues right off the top of my head.. there can be many others depending on the culture techniques. 

Ed


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## frogfreak (Mar 4, 2009)

guppygal said:


> I've been feeding Hydei exclusively for 7 yrs - I just now added mels for my newly morphed auratus froglet and my imitators. It drives me nuts when those tiny flies start using their darn wings....
> 
> k


Wingless melano's.... my favorite fly. They behave much like an ant.

I'm surprised to see many people having trouble with Hydei. They produce like crazy for us! We take flies from multiple cultures and have never had a culture fail. We never use yeast on the surface either.


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## guppygal (Aug 23, 2007)

Gosh, there's that 'yeast' thing again....

I've never tried bean beetles, but wouldn't mind giving it a whirl, as long as I don't have to sterilize all my equipment.... 

BTW, Ed - do you have problems with your hydei cultures? Just asking ~


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## Ed (Sep 19, 2004)

guppygal said:


> Gosh, there's that 'yeast' thing again....
> 
> I've never tried bean beetles, but wouldn't mind giving it a whirl, as long as I don't have to sterilize all my equipment....
> 
> BTW, Ed - do you have problems with your hydei cultures? Just asking ~



Actually no it isn't that yeast thing again... a culture is a uncontrolled bioreactor with a lot of things converting O2 to CO2.... As I noted, fruit flies are normally adapted to live in lower O2 (higher CO2 enviroments..) 

No, I didn't have any problems with the hydei (other than they are consumate escape artists and I got tired of finding them crawling on me and in my drinks after I fed them out) and I was culturing them for years. 
I've cultured hydei both by themselves and cocultured with melanogaster. If you coculture with melanogaster you get a much more continous supply of flies from a culture and a greater utilization of media. 
Its just with the bean beetles, all I have to do is add dry beans and beetles to a culture so it is easier for me. They are just as good as hydei at escaping so that part is a wash for me. 


Ed


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## guppygal (Aug 23, 2007)

I feel your pain. I'm sure that at some point in time, all long-term pdf hobbyists become accustomed to that yummy buggy taste....mmmmm, good....!

k


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## BlueRidge (Jun 12, 2010)

ED, where do you get those beetles?


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## Ed (Sep 19, 2004)

Your best bet is local shows and hobbyists as they are technically illegal to ship across state borders as they are a plant pest. 

Ed


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## TDK (Oct 6, 2007)

I've cultured hydei both by themselves and cocultured with melanogaster. If you coculture with melanogaster you get a much more continous supply of flies from a culture and a greater utilization of media. 
Its just with the bean beetles, all I have to do is add dry beans and beetles to a culture so it is easier for me. They are just as good as hydei at escaping so that part is a wash for me. 


Ed[/QUOTE]

Cocultured--I accidentally mixed a group this week when making new cultures and just put a large red X on the top so I could identify the culture. I had no idea it could possibly be a benefit. I also didn't know if they could crossbreed--I guess from your comment the answer to that is no. Are you using more bean beetles than fruit flies now?


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## Ed (Sep 19, 2004)

TDK said:


> Cocultured--I accidentally mixed a group this week when making new cultures and just put a large red X on the top so I could identify the culture. I had no idea it could possibly be a benefit. I also didn't know if they could crossbreed--I guess from your comment the answer to that is no. Are you using more bean beetles than fruit flies now?


I am using about the same amounts of fruit flies as I am bean beetles at this time. By setting up a couple of cultures a week of bean beetles, I now have cultures producing each week which allows me a pretty constant supply of them. 

They do not interbreed and you should see a more constant supply of the flies. You'll probably need to keep a couple of unmixed cultures going to make sure you have some available to set up new cultures (if you decide you want to keep making cocultures). 

I got the idea originally from Mike Shrom.. 

Ed


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## RentaPig311 (Jul 6, 2009)

This has turned into a very informative thread. I can't belive I messed up my chance to get at some bean beetles this week. Oh well. Thanks for the input guys.


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## zBrinks (Jul 16, 2006)

Does Cindy have any? I was living in Denton when I got my first frogs (attending UNT) - she's not that far away, in Wylie. It would surprise me if she didn't have bean beetles.

Cindy Dickens
VivariumConcepts.com


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## vjf000 (Jun 14, 2008)

bean beetles can be purchased from carolina biological supply


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## fishieness (Jun 26, 2009)

I've only been culturing hydei for a few months, but haven't had any problems. I've also waiting a while before starting a new culture (a month or so) so maybe that negates the likelihood of giving me only one sex. I like them. My big frogs love them, they produce really well, and the cultures last a while. I've been wanting to try bean beetles too. I'll have to get a culture next time I find them. Though my pumilio and vents probably wont be able to eat them. Maybe I'll just have to get some more big frogs to eat the leftover.


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## Ed (Sep 19, 2004)

fishieness said:


> I've only been culturing hydei for a few months, but haven't had any problems. I've also waiting a while before starting a new culture (a month or so) so maybe that negates the likelihood of giving me only one sex. I like them. My big frogs love them, they produce really well, and the cultures last a while. I've been wanting to try bean beetles too. I'll have to get a culture next time I find them. Though my pumilio and vents probably wont be able to eat them. Maybe I'll just have to get some more big frogs to eat the leftover.


I have pumilio that took hydei and will take bean beetles. 

Ed


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## Rain_Frog (Apr 27, 2004)

I think I figured out what might have happened. Perhaps I should have wiped the sides of the container as I mixed the media. In a new culture I made, a LOT of hydei were stuck against the side of the container by their wings. Many were still alive, but not much I could do about it in a new culture I set up.


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## Gamble (Aug 1, 2010)

I dont know if it has any bearing but ive read/heard that TOO much yeast can cause infertility in the flies, aside from turning the medium into "soup" at first ... Ive never added yeast to my Hydei cultures and have never seen a problem. I have noticed that my cultures BOOM at first and then nothing soon after but tons of empty egg casings. Ive always only gotten one good production per culture intially towards the beginning of making the culture. Also, the age of the flys in the culture transferred to the new culture has some bearing too ... Is all this correct?


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## Ed (Sep 19, 2004)

Gamble said:


> I dont know if it has any bearing but ive read/heard that TOO much yeast can cause infertility in the flies, aside from turning the medium into "soup" at first ... Ive never added yeast to my Hydei cultures and have never seen a problem. I have noticed that my cultures BOOM at first and then nothing soon after but tons of empty egg casings. Ive always only gotten one good production per culture intially towards the beginning of making the culture. Also, the age of the flys in the culture transferred to the new culture has some bearing too ... Is all this correct?


 
First: the yeast does not cause infertility. It is a nutrient source for the flies (both in nature and in cultures), nor is it the reason your cultures turn soupy. The soupiness is caused in part by having too much moisture in the cultures (whether due to too high a humidity in the room), in part by the digestive enzymes actively excreted by the maggots into the media and in part due to the total microbial action on the media. 


Second: your cultures boom and then crash because you have selected them to be genetically intolerant of conditions in the culture once the first flies emerge. This has been discussed a number of times on the forum. 

Third: Those are not eggs you are observing being left empty, they are pupal casings. 

Fourth: The age does play a part with hydei but a bigger issue in thier culture is the fact that there is a difference in when males and females emerge from the pupa. 

Fifth: Most of this was discussed in a post in the above thread (see http://www.dendroboard.com/forum/513582-post32.html ) 


Ed


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## Gamble (Aug 1, 2010)

Ed said:


> First: the yeast does not cause infertility. It is a nutrient source for the flies (both in nature and in cultures), nor is it the reason your cultures turn soupy. The soupiness is caused in part by having too much moisture in the cultures (whether due to too high a humidity in the room), in part by the digestive enzymes actively excreted by the maggots into the media and in part due to the total microbial action on the media.
> 
> 
> Second: your cultures boom and then crash because you have selected them to be genetically intolerant of conditions in the culture once the first flies emerge. This has been discussed a number of times on the forum.
> ...



"Second: ... " ... What does that mean exactly??? (Your point #2) ... EDUCATE ME ED! Lol


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## Ed (Sep 19, 2004)

Gamble said:


> "Second: ... " ... What does that mean exactly??? (Your point #2) ... EDUCATE ME ED! Lol


 
http://www.dendroboard.com/forum/food-feeding/42419-genetics-ff-culturing.html

Ed


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## Gamble (Aug 1, 2010)

Very Interesting Ed ... Thx for the knowledge! I learn something new everyday! So basically, instead of starting a new culture as soon as one booms and letting it run out I should continue adding the "old" flies to the replacement culture in addition to a 2nd culture and keep rotating the stock in each culture instead of isolating the flies to the one culture every time the next culture is made? (Does that make sense?)


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## guppygal (Aug 23, 2007)

guppygal said:


> Okay, I've got 3 test bottles set up:
> bottle 1 - fresh culture, added liquid, added baker's yeast, added Hydei
> bottle 2 - fresh culture, added liquid, added Hydei - no baker's yeast
> bottle 3 - fresh culture, added liquid, added baker's yeast, will add Hydei in two days
> ...


Okay, folks - the results are in. The yeast (in my case) had absolutely nothing to do with the hydei lifespan, or lack thereof. I examined all three cultures last night and each one is full of larva. There were a couple of dead flies in each culture, but nothing to get excited about. 

I humbly bow to Ed's expertise in all matters fruitfly 

kristi


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## Ed (Sep 19, 2004)

Gamble said:


> Very Interesting Ed ... Thx for the knowledge! I learn something new everyday! So basically, instead of starting a new culture as soon as one booms and letting it run out I should continue adding the "old" flies to the replacement culture in addition to a 2nd culture and keep rotating the stock in each culture instead of isolating the flies to the one culture every time the next culture is made? (Does that make sense?)


 
What it means is just don't use the first emergence as the sole starting point. If you do that you will get flies that emerge more quickly but die within a couple of days in the container. With hydei due to their longer development time (17-25 days) and how long cultures can be kept around due to mite issues, it isn't as easy as melanogaster but try to make new cultures with a mixture of older flies and newer flies (as you will have more emerging from culture over time). 

Ed


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## Ed (Sep 19, 2004)

guppygal said:


> Okay, folks - the results are in. The yeast (in my case) had absolutely nothing to do with the hydei lifespan, or lack thereof. I examined all three cultures last night and each one is full of larva. There were a couple of dead flies in each culture, but nothing to get excited about.
> 
> I humbly bow to Ed's expertise in all matters fruitfly
> 
> kristi


 
Sometimes you young whippersnappers should listen to us older curmudgeons..... 

Ed


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## guppygal (Aug 23, 2007)

LOL...thanks ~ I need that...


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## Rain_Frog (Apr 27, 2004)

and if you didn't notice, I figured out the source of my problem. The flies were getting stuck against the sides of the container by their wings. Since I went back to using excelsior and doing a better job wiping the sides when I add media, much less mortality of flies getting stuck.


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## guppygal (Aug 23, 2007)

I had the same problem with my flies dying, but I use excelsior exclusively. This was during the middle of the summer, so maybe the heat had something to do with it.


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