A polyclonal antibody raised against locustamyoinhibin (Lom-MIH), a myoinhibiting neuropeptide of the locust Locusta migratoria, was used to search for locustamyoinhibin-like immunoreactivity in the central nervous system of the gray fleshfly, Neobellieria bullata, the Colorado potato beetle, Leptinotarsa decemlineata, the cabbage moth, Mamestra brassicae and the cockroach, Leucophaea maderae. In L. maderea, immunoreactive cells are present in the pars intercerebralis (PI), in nerve fibers leading to the corpus cardiacum (CC) and in the CC themselves. In N. bullata, three groups of cells are positive: one in the PI, one in the pars lateralis and one in the suboesophageal ganglion. In M. brassicae, there are only positive cells in the PI. No immunoreactivity was found in L. decemlineata. These results indicate that the presence of Lom-MIH immuno-like molecules is not restricted to the orthopterans, and that they can be localized in different parts of the head ganglia.