I'm so sorry in not replying to those who wrote and wished me to send further info on my Saguaro problem. I had some problems getting pics, then I really had time problems.
Anyway, I think I've downloaded 2 pics of the Saguaro since topping it, whenever I topped it, about a week into June.
It was my intentention, (after hacking away at it in the late evening with a machete, to relieve it of it's liquid scum and parasites), to return with a chainsaw, and undercut the hacks with a more smooth cut. That never happened.
By the way, the creatures I mentioned, appear to have been maggots, just maggots that I've never seen before, and probably horsefly maggots. They apparently did little damage to to plant.
The plant seems to be healthy without it's top. I never applied anything to it, although I did plan to. There has been no rain here since, but the monsoon is starting. We're into to temps approaching 120, and I hoped that, and the earlier high temps might take care of the top of the cactus.
Thanks again for all your input and interest.