DEVELOPMENTAL-CHANGES IN BIOGENIC-AMINE LEVELS IN THE CENTRAL-NERVOUS-SYSTEM AND THE HEMOLYMPH OF THE EASTERN-DEATHS HEAD-HAWK-MOTH, ACHERONTIA-STYX (LEPIDOPTERA, SPHINGIDAE)

In an effort to understand the role of biogenic amines in insect devel opment, changes in the levels of octopamine (OA), dopamine (DA), epine phrine (E), norepinephrine (NE), and serotonin (5-HT) in the brain, th e optic lobes and the haemolymph of different developmental stages of Acherontia styx were analyzed using HPLC with electrochemical detector . In the brain, OA was the most abundant monoamine. DA, OA, and E leve ls in larvae peaked around the wandering stage (W). A dramatic increas e in DA, 5-HT, and E levels was observed in the brain of the adult as compared to the pupal stage. NE, however, was not detected in the brai n of most stages of the insect, except in the brain of 20-day-old pupa e and adults. A 3-fold increase in OA levels was observed in the optic lobes of the adult as compared to late pupal stage. No changes were o bserved for E, DA, and 5-HT. NE was not detected in the optic lobes. I n the haemolymph of 5(th) instar larvae, OA was also the most abundant amine. Both DA and OA peaked prior to the onset of the W stage. In co ntrast, E and NE concentrations decreased with development of the 5(th ) instar larvae. 5-HT was not detected in the haemolymph. Finally, dif ferent profiles for amine levels were observed for the two forms of th e 5(th) instar larvae (green vs brown). These results are interpreted in the light of the role of biogenic amines and their relation to deve lopment in the nervous system of lepidopteran insects. (C) 1997 Elsevi er Science Inc.