Which of the following is NOT one of the four types of insect hemocytes listed?

• A. Prohemocytes
• B. Plasmatocytes
• C. Granular hemocytes
• D. Oenocytoids

Answer: (D)

Insect hemocytes are classified into several types based on function and morphology, and many introductory frameworks list four main categories: prohemocytes (the stem-cell precursors), plasmatocytes and granular cells (the primary phagocytic and encapsulating cells), and adipohemocytes (involved in lipid storage and related functions). Oenocytoids, while a recognized hemocyte type in many species and known for roles in enzymatic defense (such as phenoloxidase release) and cuticle hardening, are not included in that four-type group used here. So when the question asks which one is not part of the four types listed in that framework, oenocytoids fit as the exception. The other options align with the four featured in that scheme, whereas oenocytoids are treated as a distinct, specialized class outside that quartet.