HEAVY METAL-AFFECTED CHANGES IN HEMOLYMPH HISTAMINE CONCENTRATION IN THE CABBAGE MOTH, MAMESTRA-BRASSICAE (LEPIDOPTERA, NOCTUIDAE)

The paper describes effects of heavy-metal exposure via food upon the level of histamine in the haemolymph of the cabbage moth, Mamestra bra ssicae (Lepidoptera, Noctuidae). Cabbage moth larvae were fed on semi- synthetic diet contaminated by Cu, Pb or Cd. The metals were administe red: a) on a single occasion, after moulting to the 6(th) instar; b) c ontinually, from the 4(th) instar onwards. Histamine (HA) concentratio n in the haemolymph of 6(th) instar larvae was determined by radioenzy matic method. Single application of Cu and Pb resulted in significant HA level increase. Continual feeding with Cu or Pb decreased haemolymp h HA content. On the other hand, continual intake of Cd-containing die t caused a significant HA level increase. Larvae refused intake of the diet contaminated with a single Cd-dose and they were starving for 48 hours. Starvation also increased haemolymph HA levels in cabbage moth larvae.