ABSTRACT
The female honey bee larva can develop into two phenotypically different forms, the queen and the worker. The feeding-behaviour of the nurse bees finally decides the emergence of a queen or of a worker. The endocrine system of insects consists of the neurosecretory cells of the brain (NSC), the corpora cardiaca, the corpora allata (CA), and the prothoracic glands. This also applies to adult honey bees. In 1st instar larvae of the honey bee, all these organs are present. In 1st instar larvae, the NSC are embryonic cells without axons. In queen larvae, outgrowth of the axons begins in the 2nd instar and is completed at the end of 3rd larval instar. The retardation of worker larvae as compared with queen larvae, is also shown in the development of the CA. From 3rd instar onward, the queen CA is always bigger in size than that of the worker.
