The cephalic neuroendocrine system in the beetle, Mylabris pustulata (thunb) (Meloidae: Coleoptera)

The cephalic neuroendocrine system in Mylabris pustulata includes neurosecretory cells in the brain, a pair of corpora cardiaca and corpora allata. There are three groups of the neurosecretory cells in each hemisphere of the brain-medial and lateral in the protocerebrum and central in tritocerebrum. They are classified into three types viz., A, B and C on the basis of staining affinities they exhibit. The axons of the medial, lateral and ventral neurosecretory cells constitute independently the medial, lateral and ventral neurosecretory pathways respectively inside the brain. The medial neurosecretory pathways emerge out of the brain as nervi corporis cardiaci I while the lateral and ventral neurosecretory pathways form collectively the other nerve, nervi corporis cardiaci II and innervate the CC. The CC contain two types of cells viz., the chromophilic, which are AF-positive and the chromophobic cells, which take the counterstain. The corpora allata are compact bodies and contain cells of one type but fluctuations in the nuclear size and the gland are occur frequently.