Which of the following is NOT part of a bee's digestive system?

In a bee's digestive system, the esophagus, crop, and rectum play crucial roles in the digestion and processing of food. The esophagus serves as the initial passage for nectar or pollen from the mouth to the crop, where it can be stored temporarily before further digestion occurs. The crop acts similarly to a stomach, allowing bees to store and partly digest their food. Finally, the rectum is responsible for the expulsion of waste material.

Hamuli, on the other hand, are small hooks found on the wings of some bees that help to hold the hind wings to the forewings during flight. They are not associated with digestion and do not play a role in the bee’s digestive system. This anatomical structure is important for the functionality of the wings but does not participate in the process of digesting or processing food. Hence, it is correct to say that hamuli are not part of a bee's digestive system.