MOSTLY ADEQUATE. “The larva and adult phases in development commonly follow totally different ways of life, and the process which Darwin called “descent with modification” and natural selection are frequently adequate to explain the differences in form that adapt them to their different environments.”
https://books.google.es/books?hl=en&lr=&id=4Bv_CAAAQBAJ&oi=fnd&pg=PR3&dq=evolution+of+larval+stage&ots=Ajv40BxpV8&sig=UoAuSNQhyUJxvYurqij18mPF3GM