Which pest specifically targets rice plants during its life cycle?

Lissohoptrus oryzophilus, commonly known as the rice water weevil, is the pest that specifically targets rice plants during its life cycle. The rice water weevil is a significant pest that primarily affects the roots and stems of rice plants. The larvae of this weevil feed on the plant tissue, which can lead to stunted growth and reduced yields. Understanding the life cycle and feeding habits of this pest is crucial for effective management and control in rice production.

Other options mentioned, while they may impact various plants, do not specifically target rice in the same direct manner as the rice water weevil. For example, Ryzoctonia oryzae-sativae is associated with diseases in plants but is not a pest itself. Triops longicaudatus, a type of crustacean, does not attack plants but rather inhabits aquatic environments. Phytonemus pallidus, known as the potato spindle tuber pathogen, primarily affects potatoes rather than rice plants. Each of these organisms interacts differently with plants, showcasing the diversity of pests and pathogens in agriculture.