Final answer:
The foliate papillae are the type of lingual papillae that are weakly developed in humans and their taste buds usually diminish by age 2 or 3 years.
Step-by-step explanation:
The type of lingual papillae that are weakly developed in humans and lose most of their taste buds by age 2 or 3 years are the foliate papillae. These leaf-like papillae are located in parallel folds along the edges and toward the back of the tongue. Although they contain about 1,300 taste buds within their folds when fully developed, these taste buds diminish significantly early in life, meaning the foliate papillae do not contribute much to our sense of taste during most of our lives.