Regarding the book To Kill a Mockingbird, What does this mean "But by the end of August our repertoire was vapid from couples reproductions" and how does it affect the action in Chapter l?

It’s Chapter 1 of To Kill a Mockingbird, and Dill has just arrived to spend his summer holidays in Maycomb. One of the things that makes Dill such a fun boy to hang out with is that he’s always coming up with exciting new ways to pass the time, and the Finch children certainly have a lot of spare time on their hands. Mainly they spend it acting out scenes from stories such as Tarzan by Edgar Rice Burroughs. Dill’s pretty useful to have around for these performances; he plays the part of an ape very well.
But as the school holidays draw to a close, things start to get pretty boring for the children. They’ve acted out the same old stories over and over again, to the point where there’s really nothing more they can add to them. Just think of all the old ideas recycled by the movies and TV. If you don’t present a new angle, if you don’t try something different, then those ideas will soon become pretty stale. That’s the problem that the children have. As the end of August approaches, they’ve found that they can no longer make the old stories fresh and exciting. They need to find a new way to pass what little time they have left of the school holidays.
It’s Dill who rides to the rescue by coming up with the Boo Radley game. Boo’s always been an object of fascination for the Finch children. But at the same time, Scout and Jem are quite scared of Maycomb’s resident boogie-man. They’ve heard all the stories about this strange individual, and so they’re reluctant to venture too close to the Radley residence. But with Dill alongside them, they get the courage to participate in his crazy idea of getting Boo to come outside.
The Boo Radley game is important for the action of Chapter 1 as it shows the Finch children engaging more closely with the world around them. The focus of their games is no longer fantasy, but reality. The relationship between Boo and the Finch children will come to be an important one as the story progresses. As the relationship develops, we’ll come to learn much more about both Boo and the Finch children. And we can say that Dill, in coming up with the Boo Radley game, is the catalyst for so much of what happens.