Figure 4. FMRFamide-like immunoreacitivity (FLI) in the retrocerebral complex (RCC) of Phormia regina. A) FLI in the retrocerebral complex and anterior dorsal surface of the midgut of P. regina. FLI processes originating from the retrocerebral complex run over the proventriculus (PV) and down the dorsal surface of the anterior midgut (double arrows), as well as down the lateral sides of the crop duct (CD) forming two crop duct nerves (CDN). B) An enlarged view of FLI in the retrocerebral complex of P. regina shows intense FLI in the corpus cardiacum/hypocerebral ganglion, as well as in the corpus allatum. Processes originating in this intense area of FLI run over the proventriculus to the midgut and down the crop duct to the crop. MG midgut; CA, corpus allatum; CC/HCG, corpus cardiacum/hypocerebral ganglion.