「」。
'I've gotten too old to play with bugs,' the boy said.
Literal
''Insects [with-と] play [for-には] I [topic-は] too-old-became,'' [quotative-と] boy [topic-は] said.
A wistful, literary line — notice how Japanese expresses 'too X to Y' differently from English. The structure ~にはXすぎる ('for X-ing, I'm too Y') uses には as a purposive marker: 'for the purpose of playing with bugs, I'm too aged'. 年をとる ('to take on years') is the standard idiom for 'to age'. ボク is masculine first person, slightly boyish but more formal than 俺.