cryoprotectants in overwintering larvae of leopard moth, zeuzera pyrina (lepidoptera: cossidae), collected from northwestern iran

Leopard moth, zeuzera pyrina l. (lepidoptera: cossidae), is one of the important woodboring pests whose larvae bore into twigs, branches, and trunks of various woody species, weakening and sometimes killing trees or shrubs. recently it has caused severe losses of walnut trees in iran. this pest overwinters as different larval instars inside trees. overwintering larvae were collected monthly from october 2020 to march 2021 from maragheh walnut orchards, northwestern iran, to determine the presence of cryoprotectants and their changes during autumn and winter. overwintering larvae accumulated sorbitol, trehalose, and myo-inositol during winter. during cold months there was approximately 11 fold and 7.5-fold increase in trehalose and sorbitol contents, respectively. glycogen content was the highest in october and decreased significantly with decreasing ambient temperature. our results suggest that the accumulation of sorbitol, trehalose, and myo-inositol plays an important role in the harsh-season survival of z. pyrina.