Its good to know I am not the only one plagued by mud wasps.... FYI I did check the impeller for alarm, I had new waterpump installed a year ago so I should be all set, it was time to replace it. I only get the alarm at full RPM when the valve is stuck shut, I also did get a bunch of weeds in there once it was blocked up by mud wasp larva, quick fix is putting the rabbit ears on it and disconnecting the valve and hitting it with carb cleaner.
Could that be plastic or corrosion of tank if you put stabilizer in the tank? Slivers of Varnish on carbs? Definitley very interesting, Do you disconnect your gas when you store your boat, It kinda looks like mud wasp grass I have gotten similar things in the pee valve...