Mud puddling formula for papilio?

Urine is 100% effective, it’s free and always available, why would you look for alternatives.

I usually have had 25-50L ( in Thailand ) of that stuff bottled at my disposal and the older batch the better effect.

I used to take several 6 litre bottles of saved urine in the back of my truck with all my other stuff when I drove to Laos for collecting trips. Luckily customs never asked to check if I was smuggling beer.
As Paul K and nomihoudai said above, old urine is definitely better than fresh out of the 'can'.

I tried using alternatives such as fish sauce, which is also full of salts and strong smelling, but that only attracted bees and flies.

It is quite interesting that urine out of the same bottle (I would take a 2 litre milk bottle with me each morning, and refill one of the 6 litre bottles each night/early morning) splashed on several sandy or muddy places on a stream bank or wet pathway in the forest have different results. Some points attracted loads of butterflies whereas others attracted nothing. Obviously it is not just the urine but also exactly what it is splashed on and where that makes a difference.

Adam.

What about the synthetic urine that people use for legal purposes? Not being an "animal" product, it's transport would have different
restrictions.

I wholeheartedly agree !

Heck, I take a 6-hour car drive once the summer to arrive at my best swallowtail collecting haunts AND I too find beer there.

And let us not forget about those (night) collecting nights around a Merc. Vap. light. Beer also has a way of finding itself there too...

Funny, how another pastime (fishing) also seems synonymous with beer 🍺.

Since I don't drink alcohol, and detest the smell of beer (urine smells better, although I wouldn't drink that either) your version of free urine wouldn't work for me.

On a more practical level, you really need the urine early in the morning and it takes a while for any liquid to become urine. It's not "in one end, out the other" instantaneously.

Adam.

The beer the night before works. And a long drive then relief. I peed on a roadside about 5pm and sure enough the next morning glaucus were there. I’ve never had luck with clear pee and returning hours later.

So back on topic. What I’m trying to do is figure out a readily available formula that can be made quickly and in volume, and doesn’t need to be transported as medical waste. You can get water in the hotel, salt, iodine, and Gatorade at the market. I wonder if that would work. I can’t imagine ammonia would be what they want, but they may be attracted to it. I dunno.