Endocrine organs of different larval instars of Spodoptera (Prodenia) litura Fabricius (Lepidoptera: Noctuidae)

Summary A₁ and A₂ cells of the median neurosecretory group are filled with PF stained neurosecretory material between the first 24 to 48 h of the earlier moult in each instar followed by immediate release before the next moult at 72 h, while loaded posterior and lateral neurosecretory cells also appear from the 3rd and 5th instars onwards. Corpora cardiaca, corpora allata and prothoracic glands increase in size in each instar.