Thermal plasticity of antioxidative activity in fresh adults of Harmonia axyridis (Coleoptera: Coccinellidae)
Abstract
High and low developmental temperatures can induce physiological stress in insects, including oxidative stress that needs to be eliminated by increased antioxidant activity. Alien invasive ladybird Harmonia axyridis (Coleoptera: Coccinellidae) possesses high toxicity and immunity defence abilities, but it is sensitive to temperatures above 35 degrees C.
We quantified the activity of antioxidative enzymes in the adult ladybirds that spent the pupal stage at moderate, low and high temperatures that can cause a physiological stress. Total antioxidant (TAO) and Glutathione S-Transferase (GST) activities of ladybirds H. axyridis were highest in extracts from freshly emerged adults developed at low temperature (17 degrees C), moderate in beetles from medium temperature (26 degrees C) and lowest in beetles from high temperature (35 degrees C).
Superoxide dismutase (SOD) activity was highest at the medium temperature. After one day of adult life at the medium temperature, antioxidative activities of individuals originated from the three temperatures became similar: low for TAO and GST and high for SOD.
Metabolic needs of the beetle organism during emerging from pupa seem to be stronger than reactions to diverse temperatures.