A novel receptor capable of monitoring applied pressure in the abdomen of an insect.

A pair of receptors, responding tonically to pressure applied internally, occurs on the ventral body wall of abdominal segments two to five in the adult of the blood-feeding insect, Rhodnius prolixus. These receptors are located in a region of the body wall subject to forces directly related to the size and movement of the stomach, an enlarged region of the midgut which stores the blood meal, and are therefore well suited for monitoring the degree of distension there. The initiation of many endocrinological processes in Rhodnius is known to be associated with the detection, over a period of several days, of abdominal distension, and these sensory receptors are capable of responding to abdominal distension for extended periods of time.