Worms are sometimes found inside apples. There’s a joke:
 
Q: What did one worm say to the other?
A: I’m moving to the Big Apple!

 
The joke has been cited in print since at least 1997.
 
     
Google Books
Squeaky Clean Jokes for Kids
By Bob Phillips and Steve Russo
Eugene, OR: Harvest House Publishers
1997
Pg. 162:
Mortimer: What did one worm say to the other?
Matilda: You tell me.
Mortimer: I’m moving to the big apple.
 
4 August 1998, Los Angeles (CA) Times, “Laugh Lines; Pint-Sized Punch Lines,” pg. 3:
What did one worm say to the other worm? “Wish me luck. I’m off to the Big Apple!” (Angie Baker, 8, L.A., Raleigh Elementary)
 
13 September 1998, Los Angeles (CA) Times, “Laugh Lines; Pint-Sized Punch Lines,” pg. 2:
What did one worm say to the other worm? Wish me luck. I’m off to the Big Apple! (Stephanie Chavez, 5, West Covina, Early Daycare Center)
 
Google Groups: alt.teens.penpals
A Question I have about sex.
merry mcgrath
9/22/98
(...)
Laugh Lines about animals?  How about:  1.  What did one worm say to the other worm? “Wish me luck, I’m off to the Big Apple!” 
 
6 December 1999, Los Angeles (CA) Times, “Laugh Lines; Pint-Sized Punch Lines, “The Kids’ Reading Room: Jokes & Riddles,” pg. 8:
What did one worm say to the other worm? “Wish me luck. I’m going to the Big Apple.” (Larry, 9, Twin Lakes School, El Monte)
 
Twitter
Psychology 200
‏@psy200tweets
What did one worm say to the other? I’m moving to the big apple! #fb
11:06 AM - 4 Feb 2010
   
Humoropedia
102 Funny Laffy Taffy Jokes
BY · PUBLISHED NOVEMBER 27, 2014 · UPDATED NOVEMBER 20, 2015
(...)
71. WHAT DID ONE WORM SAY TO THE OTHER? I’M MOVING TO THE BIG APPLE!
 
Twitter
Bill Helton
‏@7colonel7
What did one Worm say to the other?  I’m moving to the Big Apple!
10:47 PM - 22 Dec 2014