Schilman Pablo E, Lighton John R B, Holway David A
Section of Ecology, Behavior and Evolution, Division of Biological Sciences, University of California at San Diego, La Jolla, 92093-0116, USA.
J Insect Physiol. 2005 Dec;51(12):1295-305. doi: 10.1016/j.jinsphys.2005.07.008. Epub 2005 Sep 9.
Respiratory water loss (RWL) in insects showing continuous emission of CO(2) is poorly studied because few methodologies can measure it. Comparisons of RWL between insects showing continuous and discontinuous gas exchange cycles (DGC) are therefore difficult. We used two recently developed methodologies (the hyperoxic switch and correlation between water-loss and CO(2) emission rates) to compare cuticular permeabilities and rates of RWL in five species of ants, the Argentine ant (Linepithema humile) and four common native ant competitors. Our results showed that RWL in groups of ants with moderate levels of activity and continuous gas exchange were similar across the two measurement methods, and were similar to published values on insects showing the DGC. Furthermore, ants exposed to anoxia increased their total water loss rates by 50-150%. These results suggest that spiracular control under continuous gas exchange can be as effective as the DGC in reducing RWL. Finally, the mesic-adapted Argentine ant showed significantly higher rates of water loss and cuticular permeability compared to four ant species native to dry environments. Physiological limitations may therefore be responsible for restricting the distribution of this invasive species in seasonally dry environments.
由于很少有方法能够测量，因此对持续排放二氧化碳的昆虫的呼吸失水（RWL）研究较少。因此，很难比较呈现连续和不连续气体交换循环（DGC）的昆虫之间的RWL。我们使用了两种最近开发的方法（高氧切换以及失水与二氧化碳排放速率之间的相关性）来比较五种蚂蚁（阿根廷蚁（Linepithema humile）和四种常见的本地竞争蚂蚁）的表皮渗透率和RWL速率。我们的结果表明，在两种测量方法中，活动水平适中且进行连续气体交换的蚂蚁群体的RWL相似，并且与已发表的关于呈现DGC的昆虫的值相似。此外，暴露于缺氧环境的蚂蚁的总失水率增加了50 - 150%。这些结果表明，在连续气体交换下气门控制在减少RWL方面可以与DGC一样有效。最后，与四种原产于干旱环境的蚂蚁物种相比，适应潮湿环境的阿根廷蚁显示出显著更高的失水率和表皮渗透率。因此，生理限制可能是限制这种入侵物种在季节性干旱环境中分布的原因。
