Any One Having Tech. of mosquito Killing ?

[3v0]

This section of text is a close setup to what I used. I do not recall that it lasted as long. It has been a while. I bolded the yeild info.

Now mix the yeast, sugar and water solution as follows.

Put 1/4 to 1/2 teaspoon of yeast into the bottle with about a cup of warm water (bread yeast is fine). Some people have theorized that champaign or wine yeast should last longer (due to its ability to tolerate the alcohol generated from the brewing process), but recent tests reported on the net have not indicated any difference.
Shake to mix the yeast well.**
Add water to bring the solution up to 3/4 of the bottle.
Add 1 to 2 cups of sugar and shake well. The amount of yeast and sugar will determine the rate and duration of CO2 generation. More yeast will result in stronger CO2 production, but will exhaust the sugar quicker. Using 1/4 teaspoon of yeast and 2 cups of sugar will result in CO2 production for about 4 to 5 weeks.
In areas with soft water, some people recommend adding a teaspoon of baking soda to buffer the water and extend the life of the solution (prevent the acid formed by the brewing action from destroying the yeast prematurely).

The brew should generate about 1 bubble per second (from the air hose with no airstone), after about one day. Using warm water will help it get going faster. There is a ramping up period in the flow at the beginning and a ramping down period at the end of the solution's productive life. To smooth out the flow, you can use two smaller (1 liter) bottles, instead of one 2-liter bottle, and start one about a week or two after the other (but this doubles the maintenance effort). You should remove and clean the airstone occasionally, as yeast-generated CO2 has a tendency to generate a slime coating that gums up the airstone after a while.

 

[Mikebits]

That seems to make sense. I guess the baking soda acts like a pH buffer which prevents denaturing the proteins in the yeast cells.

I think you could speed up the gas production in a few ways. One is to use brewers yeast (which was stated in your link).
Adding much more yeast would also help, I would think the gas production time increases exponentially as the yeast cells multiply until the carb supply is used up. 5 weeks seems a bit long to me, but maybe so.

Using glucose like corn syrup would also yield faster results as the yeast cells have to generate the enzyme invertase to break down sucrose into glucose, so glucose would remove the invertase production from the equation. Of course 1 mole glucose only yields 2 mole CO2 so more glucose would be needed.

I actually did an experiment like this in one of my Bio labs, observing fermentation. We tested amount of CO2 gas generated over time (2 hours) comparing results of yeast fermenting glucose and sucrose.

I can't remember the amount of CO2 measured. I think it was a few milliliters.

 

[3v0]

I will be traveling to civilization next week. The talk about aquatic plants has caused me to become nostalgic. Maybe I will pick up a few and setup a tank.

 

[Mikebits]

I will be traveling to civilization next week. The talk about aquatic plants has caused me to become nostalgic. Maybe I will pick up a few and setup a tank.

Not to be a wiseguy or anything, but yeast is a member of the Fungi Kingdom?

 

[Mikebits]

Again I don't know why, too much time on my hands I guess, and to avoid doing homework, I made a excel spreadsheet for CO2 gas production based on amount of sucrose or glucose. I was puzzled at first as my spreadsheet showed the equal grams of sugar and glucose produced same amount of CO2. Then it occurred to me that glucose has half the molecular weight as sucrose, so then it make sense.

If anyone is interested, I am providing the spreadsheet. Why you would want it, I have no idea. Maybe useful to beer makers

Update.
This spreadsheet is bogus, so don't bother to DL it. I will fix it and post a corrected version. My apologies to anyone hat wasted the time to DL this one...

Ya know, crow taste like chicken...

 

[arrie]

I've actually made a couple of traps some time back to attempt mozzy culling.
I used the sugar, water and yeast approach - the two traps yielded no result.

What about dry ice - I've heard these release quite a bit of CO2 - I even saw footage of how a can with a piece of dry ice lure blood sucking bugs from sand in dessert areas and the can quickly filled with these parasites as they were looking for the host.

Another lesson - in sub desset areas in Africa - do not go and take a rest under a tree - these guys will make you look like a raison.

 

[Pommie]

I don’t know why but I got curious as to how much CO2 gas could actually be obtained using the Sugar yeast method, not sure how much yeast is needed but since it undergoes mitotic reproduction during anaerobic respiration I assume not a lot is needed .Anyways, if I did this right then;
From the chemical formula for sugar to CO2 we get:

C12H22O11 ----> 4 CO2 (I left out the other products) So 1 mole sucrose yields 4 mole CO2
1mole C12H22O11 is about 342g/mole which is about 3/4 pound of sugar.
1 mole of sugar will make about 4(44g CO2/1 mole CO2) = 176 g CO2.

Since density of CO2 is 1.56g/ml the amount of CO2 produced from 1 mole of sugar is

1 mole C12H22O11 ----> 176g CO2 x (1mL/1.56g CO2) = 112.8 mL CO2

So for ¾ pound of sugar you would fill up about 1 of these (image below) graduated cylinders with CO2. Not a lot of gas for that much sugar.
This assumes conditions are at STP.

I thought a mole of any gas always occupied 22.4 Liters.

Mike.

 

[Mikebits]

I thought a mole of any gas always occupied 22.4 Liters.

Mike.

Your right, I screwed the pooch somewhere. I need to look at where I messed up. For one thing, my equation of sugar to gas is wrong. Should be more like; sugar----> 12 CO2.
Edit-------------
Wait a sec 12 CO2 is for aerobic respiration. Anaerobic is 4Co2. It is getting late. I will check again when I am not so tired. Sorry for any confusion, if anyone actually cared...

Oops

 

[3v0]

Was it that there was not enough CO2 or was it that your method of collecting/killing them did not work?

IF I were to try this method I would not use less then 5 gallons of water and a few lbs of sugar. A bit on the expensive side to operate but once or twice a year for a party would be OK.

Then there is wind. The initial test should be done on a dead still day.

3v0

I've actually made a couple of traps some time back to attempt mozzy culling.
I used the sugar, water and yeast approach - the two traps yielded no result.

What about dry ice - I've heard these release quite a bit of CO2 - I even saw footage of how a can with a piece of dry ice lure blood sucking bugs from sand in dessert areas and the can quickly filled with these parasites as they were looking for the host.

Another lesson - in sub desset areas in Africa - do not go and take a rest under a tree - these guys will make you look like a raison.

 

[transistor495]

Dry ice or any other fast methods may become dangerous if used inside a closed room for a whole night.
If it's too slow, bugs will go to the concentrated areas where we are breathing and won't be efficient.
A detailed study should be there I think before any try.
Also a pulsed emission of CO2 passed through a heated container make some warmth and simulation of breathing. I'll also make it a try.

 

[3v0]

Dry ice or any other fast methods may become dangerous if used inside a closed room for a whole night.
If it's too slow, bugs will go to the concentrated areas where we are breathing and won't be efficient.
A detailed study should be there I think before any try.
Also a pulsed emission of CO2 passed through a heated container make some warmth and simulation of breathing. I'll also make it a try.

One would need to keep the dry ice in a cooler so only enough CO2 was generated. That should pose no problem because you want about the same amount of CO2 as one or two people generate.

I was not thinking indoors. Maybe best to try it in a room without people first so the m's are not distracted by people. If that works try it with people.

 

[Mikebits]

I thought a mole of any gas always occupied 22.4 Liters.

Mike.

Well I am embarrassed. Looks like my approach of using the density formula was off base. Looks like 4 mole of CO2 is more like 89L of gas, boy was I way off. I redid the spreadsheet to fix the error. Please correct me if my excel sheet is wrong this time...

To play with the spreadsheet, just change the blocks colored in aqua

 

[3v0]

Good thing it was not homework !

 

[Mikebits]

I am glad to say Gen chem is a semester or two behind me, but always good to practice what you learned in the past. I can see now that I need it

 

[audioguru]

For many years my city had many mosquitoes and bats. Now they are gone.
Because now the city drops an anti-insecticide in each rain drain, swamp and pond a couple of times a year.
So hardly anybody gets West Nile Virus anymore.

 

[Speakerguy]

Because of West Nile our city here in East Texas started treating against mosquitos. I get bit much, much less frequently than I ever remember. Mosquitos used to be terrible here, especially since I have a large woods behind my house with a creek running through it.

All it took was for West Nile to paralyze one of our city's police officers. Last I heard the guy is still learning to walk again after two years in a bed/wheelchair.

 

[transistor495]

Here in my area, mosquitoes are big in size and have teeths sticking out I can see. They used to prallethrin insecticide and seems now they like it.

Few years before I've made an ultrasonic repeller working at something above 20KHz but used a tweeter instead of ultrasonic transducer. No effect!

One of my frnd had made 555 based 15KHz osc and used with a normal speaker as he had no tweeter in stock. First day he told that it's working as he was very proud of his first work. Next day he told that mosquitoes are mainly concentrated on the speaker cone area

Mosquito coils are available but very injurious to health and we can feel it on the next morning. Rackets are funny but producing noise and no effect on the smartest ones hiding under the bedside only come out when the light went out and even they measure our breath rythm which is going to sleeping stage and sing inside ears - 'me'eeeeeeemememe...
If GOD appears and ask me what u want, I will tell him to terminate all mosquitoes from earth.

 

[audioguru]

Here in my area

Why doesn't your government get rid of the dangerous mosquitoes like my government did?

 

[Pommie]

Well I am embarrassed. Looks like my approach of using the density formula was off base. Looks like 4 mole of CO2 is more like 89L of gas, boy was I way off. I redid the spreadsheet to fix the error. Please correct me if my excel sheet is wrong this time...

To play with the spreadsheet, just change the blocks colored in aqua

I think your original calculation was probably correct (I didn't check it). I think your mistake was that you calculated the volume of liquid CO2 instead of gas. Not really embarrassing at all.

Mike.

 

[HarveyH42]

Why doesn't your government get rid of the dangerous mosquitoes like my government did?

Mosquitoes also happen to be food for many young and small critters, which also happen to be food for larger critters. Killing them all would create other problems. The chemicals used to kill large quantities of anything, can't be good for people either. Canada blames all bad things on the USA, so it's okay.