Oxygen Consumption and Rates of Dehydration of Grasshopper Eggs (Orthoptera)

The rate of water loss of Melanoplus differentialis eggs at different developmental stages has been determined. No qualitative difference in respect to rate was found between wet (hypertonic solutions) and dry (calcium chloride) dehydration. The resistance to desiccation decreases with morphological age of developing eggs. Diapause eggs are most resistant. The rate of desiccation does not seem to be closely associated with metabolic activity as represented by that fraction of the respiration which is dependent on structure, or which may he depressed by certain CO/O2 mixtures. Isolated embryos do not show qualitatively the same dehydration rate difference as do intact eggs. The oxygen consumption of dehydrated eggs decreased during water loss. In no cases was an increase observed during dehydration. The vital limit of desiccation of post-diapause eggs was found to be about 46% of the initial water.