Age-Related Effects on Water, Lipid, Hemoglobin, and Critical Equilibrium Humidity in Unfed Adult Lone Star Ticks (Acari: Ixodidae)1

Age-related changes over 12 months were examined in 2 laboratory-reared populations of ticks. Most ticks survived and water content did not change significantly with increasing tick age. The measured critical equilibrium humidity for all ticks other than those that had recently molted was 80–85%. Recently molted ticks did not absorb water from unsaturated air. There was an apparent decline in body lipid, but variation between replicates was large. Of the parameters studied with increasing tick age, the greatest change was observed in heme content.