Abstrakt: |
This study shows that water stress is not countered in eggs of the lone star tick, Amblyommaamericanum (L.), using water vapor, and suggests involvement of liquid water as a developmental cue. Eggs fail to maintain an equilibrium water content in subsaturated air, hence, gain≠loss, with net water losses occurring at relative humidities near saturation and these eggs exhibit a three-fold drop in viability, but not incubation period, as compared to eggs held in saturated air. Amblyommaamericanum eggs are stenohydric and feature low 58% water content, slow water losses <1%/h, and an impermeable chorion wherein the Arrhenius activation energy, Ea=−66J/K, is suppressed. Thus, enhancement of water retention, not water vapor absorption, permits eggs to resist desiccation. [ABSTRACT FROM AUTHOR] |