Median neurosecretory cells and associated nerves of the adult black blow fly, Phormia regina (Diptera: Calliphoridae)

The neuroendocrine system and stomatogastric nervous system of the adult black blow fly, Phormia regina (Meigen), were observed. No frontal ganglion or ganglionlike structure was found in P. regina . In its place, there is a three-way nerve junction made of two labrofrontal connectives and the recurrent nerve. Neurosecretory granules (NSG) are found in some axons of the junction. Two types of neurosecretory cells can be identified in the pars intercerebralis of the brain. Shortly after leaving the brain, the nervi corporis cardiaci approach and join with the recurrent nerve to form a larger nerve bundle, the cardiac-recurrent nerve.