PSP game: Where to catch beetles in summer vacation?

There is a secret base under the bridge. I met the vice principal for the first time.

Go to the "secret base" to trigger the plot.

Then go to the oak tree. Under the oak tree, there is ...

Where is the oak tree? Remember the road that Meng asked you to help pick flowers? There are two trees there.

Cut down the tree in the future, and there will be another tree across the river.

Talk to your aunt at night after catching the beetle. Aunt will tell you to attract more beetles with white sugar water, and then find white sugar to make in the kitchen.