Re: How much nitrogen is in a avg. cricket or fly at any given time?

Jereme,

First, I will assume that you are talking about the molecular nitrogen there 
due to breathing/respiration (N2), as opposed to all of the atomic nitrogen 
that is present in the various molecules that make up the body of the 
cricket (N).  I don't know the answer to this, but I think it is pretty 
easily estimated.  First, I would guess that a cricket occupies somewhat 
less than a cubic centimeter (which equals 1 milliliter) of space, maybe 0.5 
cm3.  Next, I would imagine that the tracheal system of a cricket occupies 
somewhere between 10% to 25% of the volume of its body, so let's say 10% for 
convenience (you can change any of these estimations based on data that you 
might know about crickets).  Next, I would assume that, given constant 
atmospheric air flow through the cricket's tracheal tubes, you can simply 
model the air in the the cricket's tracheal tubes as atmospheric air.  
Finally, knowing that air is 75% molecular nitrogen by weight (which I 
looked up), and that the density of air is 1.16 g/L at ambient pressure and 
temperature (which I also looked up), you can calculate the weight of 
nitrogen in a cricket at any average time.  This calculation would be:

(0.5 cm3)*(0.1)*(1 mL/1 cm3)*(1 L/1000 mL)*(1.16g/L)= 0.000058 g = 0.058 mg

Chris