Hi there!
This is mi first post here as I've only just found the Psychonaut site. Looks damn good to me! But anyway - onto the matter being discussed:
I've been picking these sacred little mushrooms for nearly 30 years and find, certainly in Europe, that the maggots & grubs only start appearing later into the season. If you pick your shrooms very soon after they emerge from good old Earth, there's none in 'em. The later in the season you get your specimens, the greater the likelihood & occurrence of the grubs. But just eat the little things anyway! If aboriginal tribes eat them (and they know much more about such things than us Western-freaks), there's obviously nothing wrong with it. Having eaten tens of thousands of these grubs down the years, with no adverse effects whatsoever, I'd say from my own (and friends) experiences that they're completely harmless.
We always like to think they might be psilocybin-containing-bugs - so scoff them 'em all up just in case there's an additional effect!
All the best - Paul