I managed to squeak 200 GS from this one but, it wasn't cooperating with me. Near the end, I had so many bug huts, that scrolling the screen would cause it to black out... and I'd need to scroll it around before the image would come back (I'd see things like the "Collect" signs, and the HUD... just nothing polygonal... weird. Definitely made it hard getting 300,000 acorns.
I never had a single issue with the Bugs not appearing. Do you return to the menu first, then use the arrow button to end the gaming session? I always did, and I had read that not exiting the game in this manner would lead to bugs not appearing (also, messing with the phone's clock apparently affected the bug appearances).