Regular treatment for parasites?

[melissa68]

Ed - not to sound chemistry or biology challenged, but what type of additional Vitamin A source are you/do you suggest to use in cultures, quantities, etc...?

Taking this a step further, what do you suggest to use for the dusting (I know some of this info is above) of fruit flies to increase this as well? Frequency?

Be kind - most of us are not working around or have access to lab scales, or reading technical journals that you might - so if you could translate some of your info that would be great. Not that we can't figure out what you are saying - just at the moment I am feeling challenged .

On a side note - Has anyone thought about or used folic acid to dust fruit flies before? As an essential building block necessary for human development I wondered if anyone has ever considered using it or have used it. I have tried it a few times - think I have noticed an improvement in egg/tad development success but have not tried to quantitatively or qualitatively monitor it's use. Usually, I will toss it into my dusting powder when I remember - could be 1-2 times a month or 3-4 times a year. Like I said - I am not sure if I had any positive results that I can back up - just curios what others think or if they have tried this.

Thanks

Originally Posted by Ed

I have been pondering the vitamin A as retinol issue for awhile now and with respect to dendrobatids, a source of vitamin A may be in the diet of the flies but it will depend in a large part on the components of the media used to rear the flies and the conditions in which the flies were reared... if the media contains sufficient carotenoids that the fruit fly can use as a precursor then the fly will synthesize 11-cis 3-hydroxyretinal from the carotenoid..
However basic potato flake recipes (standard used in labs) contain very little in the way of carotenoids like beta carotene (about 21 mcg of beta carotene and 88 mcg of vitamin A as retinol per cup of rehydrated flakes). This is then subjected to a fermentive culture in which the flies are reared and fed causing the maggots and the flies to compete with the yeast and bacteria for these food items potentially resulting in the published analysis that fruit flies are deficient in retinol.

The levels may also be affected depending on when the flies were removed from the cultures.. so earlier batches of flies may contain greater levels of 11-cis 3-hydroxyretinal than later batches of flies.

So to get to the point, if a media was used that contained a sufficient source of carotenoid the flies would have a higher level of 11-cis 3-hydroxyretinal which when combined with a supplement allows for a sufficient supply of vitamin A to the tadpoles. This could be one of the possible differences seen in the success of some people with obligate egg feeders.

Now this train of thought is not proven but you can see the connections together above...
Some thoughts..

Ed

[Jason]

I wonder if making sweet potato, squash, etc. cultures would help.

The orange-colored fruits and vegetables including carrots, apricots, mangoes, squash, and sweet potatoes contain significant amounts of beta-carotene, alpha-carotene, and beta-cryptoxanthin.

Green vegetables, especially spinach, kale, and collard greens, also contain beta-carotene, and are the best sources of lutein.

WHFoods: carotenoids

[Ed]

Originally Posted by melissa68

Ed - not to sound chemistry or biology challenged, but what type of additional Vitamin A source are you/do you suggest to use in cultures, quantities, etc...?

This to some extent is all guesstimates as I have yet to see an analysis on it.. Personally I add some spirulina to my ff media to bump up the levels of available carotenoids as not only does it contain several different carotenoids but depending on the strain it can have a lot more beta carotene than carrots or sweet potatos.
For those who want to peruse ff nutritional requirements see The Nutritional Requirements of Drosophila Melanogaster -- BEGG and ROBERTSON 26 (4): 380 -- Journal of Experimental Biology

As to amount, given that the flies are in effect living in a uncontrolled bioreactor with all kinds of other organisms.. your guess is as good as mine. For more than a year now I have been adding about a teaspoon per cup of dry media at the time I make up the cultures (otherwise the spirulina is stored in the freezer to dimish oxidation).

Originally Posted by melissa68

On a side note - Has anyone thought about or used folic acid to dust fruit flies before? As an essential building block necessary for human development I wondered if anyone has ever considered using it or have used it. I have tried it a few times - think I have noticed an improvement in egg/tad development success but have not tried to quantitatively or qualitatively monitor it's use. Usually, I will toss it into my dusting powder when I remember - could be 1-2 times a month or 3-4 times a year. Like I said - I am not sure if I had any positive results that I can back up - just curios what others think or if they have tried this.

At least some of the common supplements already contain folic acid as do the ffs and the brewer's yeast used in many of the cultures....
It should be stored in the liver and the occasional (stress occasional here) addition is unlikely to be harmful but real excesses can cause problems including seizures.

Some thoughts,

Ed