Some Features of Water Saving in Aporia crataegi L. Caterpillars Inhabiting Areas of Dry Climate in Eastern Siberia (Yakutia, Russia)

Climate in Yakutia is characterized by low winter and hot summer temperatures that cause extreme low air humidity reaching up to 30% in varied periods. Therefore, insects in Yakutia are seasonally faced to extremely dry air that forced them to create special adaptation mechanisms during evolution. Estimation of water balance for Aporia crataegi L. caterpillars was based on measurements of rates of water loss, respiration and total water content. Our research shows that Aporia crataegi exposed to dry environmental conditions have low cuticular water permeability that was close to that of African beetles. This mechanism allows the insect to keep significant amount of water: up to 70% inside their bodies despite extreme dry conditions that surround them. The study shows that another mechanism making up insect water balance during winter associated with production of ice nucleating proteins transforming water into ice in an insect’s hemolymph is not sufficient for the given species. Additionally, a cocoon they are hidden inside since early autumn, the whole winter and spring also protect the caterpillars from dissociation. tolerant Acanthocinus aedilis larvae was shown that they have a low cuticular water permeability preventing it from excessive water loss [9]. Interestingly, that this species is not only freeze tolerant, but has also developed ability to supercooling. The study was based on measurements of rates of water loss and metabolism of the larvae and data were then related to water balance curve of the African desert beetles obtained by Zachariassen et al. [10] (Figure 1). According to Figure 1, the regression line presents the rates of water loss of various