Benoit Joshua B, Del Grosso Nicholas A, Yoder Jay A, Denlinger David L
Department of Entomology, The Ohio State University, Columbus, Ohio 43210, USA.
Am J Trop Med Hyg. 2007 May;76(5):987-93.
To determine how the bed bug, Cimex lectularius, survives in a dry environment for many months without feeding, water-balance characteristics were compared for all stages from first-instar nymphs to adults. This species is characterized by a low net transpiration rate averaging < 0.2%/h, high tolerance for dehydration (30-40% loss in body water), and an impermeable cuticle as indicated by a high critical transition temperature (CTT) in the 35-40 degrees C range, implying that this insect is adapted for desiccation-hardiness. The capacity of adults to survive for 2 weeks at 0.00a(v) (a(v) = % RH/100) with no access to food or water exemplifies this trait. In contrast to more mature stages, first-instar nymphs contain more water, lose water at a faster rate, experience abrupt water loss at a lower temperature, and survive less time in dry air, suggesting that this stage is the most sensitive to water stress. This insect relies on blood to replenish water stores; none of the stages examined have the capacity to absorb water vapor (critical equilibrium activity, CEA > or = 0.99a(v)), and they drank only sparingly when offered free water. As the bed bugs progress through their development, they gradually reduce their water requirements while increasing their desiccation resistance. Surviving water stress is considerably enhanced behaviorally by quiescence, characterized by prolonged periods of inactivity, and by the formation of clusters that generate a water-conserving group effect.
为了确定臭虫（温带臭虫）如何在干燥环境中不进食存活数月，对从一龄若虫到成虫的各个阶段的水平衡特征进行了比较。该物种的特点是净蒸腾速率低，平均<0.2%/小时，对脱水具有高耐受性（身体水分损失30 - 40%），以及角质层不透水，这表现为临界转变温度（CTT）在35 - 40摄氏度范围内较高，这意味着这种昆虫适应了耐干燥能力。成虫在0.00a(v)（a(v)=相对湿度%/100）下不获取食物或水存活2周的能力就例证了这一特性。与更成熟的阶段相比，一龄若虫含水量更高，失水速率更快，在较低温度下经历突然失水，并且在干燥空气中存活时间更短，这表明该阶段对水分胁迫最敏感。这种昆虫依靠血液补充水分储备；所检查的任何阶段都没有吸收水蒸气的能力（临界平衡活性，CEA≥0.99a(v)），并且当提供自由水时它们也只是少量饮水。随着臭虫的发育，它们逐渐降低水分需求，同时提高耐干燥能力。通过静止（以长时间不活动为特征）和形成聚集（产生节水群体效应），在行为上大大增强了对水分胁迫的耐受性。
