Desiccation resistance

Figure 6.6 Within- and between-population variation in desiccation resistance (A) and cuticular lipid quantity (B) as a function of body melanization in northern and southern Indian populations of Zaprionus indianus and Drosophila melanogaster. In both species, populations from drier (northern) habitats are more desiccation resistant. The desiccation-resistant population of D. melanogaster is melanic, whereas desiccation resistance in Z. indianus is correlated with higher amounts of surface lipids. From Parkash et al. (2008a) reproduced with permission.

Gibbs, A. G., Chippindale, A. K. and Rose, M. R. (1997). Physiological mechanisms of evolved desiccation resistance in Drosophila melanogaster. J. Experim. Biol., 200, 1821-1832. 

Parkash, R., Kalra, B. and Sharma, V. (2008a). Changes in cuticular lipids, water loss and desiccation resistance in a tropical drosophilid - analysis of within population variation. Fly, 2,187-197. 

Parkash, R., Rajpurohit, S. and Ramniwas, S. (2008b). Changes in body melanization and desiccation resistance in highland vs. lowland populations of Drosophila melanogaster. J. Insect Physiol., 54, 1050-1056. 

Parkash, R., Ramniwas, S Rajpurohit, S. and Sharma, V. (2008c). Variations in body melanization impact desiccation resistance in Drosophila immigrans from Western Himalayas. J. Zool., 276, 219-227. 

We are just beginning to evaluate why cuticular hydrocarbons are especially suited to regulate reproduction. It could be that the specificity of biosynthesis and transport to ovaries, eggs, and cuticle is important here (Smith et al., 2009). Alterations in the profile may increase water permeability, making hydrocarbon profiles a signal that is reliable because of the associated costs of potentially lower desiccation resistance (Hefetz, 2007). On the other hand reproductive individuals usually stay in nest areas with high humidity. 

B. Fanning, P.H. in t Veld, S. Notermans and J. Kramer, J. Appl. Bacteriol. 11 (1994) 319. B. Fanning, Studies on the desiccation resistance of various bacterial strains PhD Thesis. Rheinischen Friedrich Wilhelms University of Bonn. Germany (1995). 

L Environmental Air. Microorganisms are ubiquitous in unprotected environments. Air is not a milieu that supports the growth of microorganisms, but it always carries a contaminant microflora of mainly desiccation-resistant microor-... 

Geographic (narrow) endemism is promoted by factors that limit dispersal. There are at least three consequences of vectoring by Drosophila that promote endemism in cactophilic yeast by limiting dispersal. The first is that the ambit of an adult fly is much smaller than the distance a desiccation-resistant spore might... 

It can be concluded from the present data that desiccation resistance markedly varies according to species. Even the most drought-tolerant lichens need a relatively high water potential to reactivate their photosynthesis (Bertsch, 1966a Lange, 1969). Consequently, areas in which air moisture rarely exceeds 75% will be hostile for lichens. This humidity limit would be of more importance than the occurrence of a few heavy showers that yield high annual precipitation. Thus, besides high desiccation tolerance the specific ability to yield substance production under poor water conditions plays a decisive role for the existence of a lichen species. 

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