I don't know off hand, but I was looking it up. I'm a curious person and if I don't know the answer I search in books and on line.http://www.learner.org/jnorth/tm/monarc
Q: How many black dots are on the monarch wings? How many white spots? Are there always the same number of spots? Do they have any special meaning? Daniela and Ashley Grade Three.
A: If you mean the black alar spots that are only found on the males, there are two of them. I don't know how many other black dots are there, nor how many white dots are there. I do know that there is some variation in the patterns of the white dots on the edge of the wings. It would be interesting to study this! Have you tried to count them? http://www.rlephoto.com/brushfoots/monarch01.htm
male larger white spots on thorax ?http://www.easttennesseewildflowers.com
This has some incredible photos.
I found in "The Monarch Butterfly, International Traveler" by Fred Urquhart, page 69
"Thus, what appears as small particles of colored dust are really minute scales exhibiting an amazing variety of shapes and sizes, each group playing its particular role. Some possess a sensory function; others produce a scent; still others impart a specific color to the butterfly; and all act as a waterproof coating. In addition, the scales and hairs are hollow structures, and along with the hollow veins and air sacs within the body, they add to buoyancy in flight--"golden feathers floating aimlessly on a warm summer's breeze."
If you look at the pattern on the wings, they seem to look like feathers.
There are many more spots on the wings than on the thorax.