Treasure Hunter Issue

I have been producing Treasure Hunters (I thought) from my home world (The Pond).  However, it does not appear that they have actually been getting produced.  Would you please take a look at the below save to see if you can see why I am not producing Treasure Hunters:

https://www.dropbox.com/s/m2hope04w8tuyjq/Treasure%20Hunters%20Under%201.50.373846.GC4Sav?dl=0

The screen snapshot below shows that I do not have any Treasure Hunter ships out hunting for treasure even though my home world has been producing them about every 3 turns.