Insects With Survival Kits for Desiccation Tolerance Under Extreme Water Deficits

Abstract

The year 2002 marked the tercentenary of Antonie van Leeuwenhoek’s discovery of desiccation tolerance in animals. This remarkable phenomenon to sustain ‘life’ in the absence of water can be revived upon return of hydrating conditions. Today, coping with climate change-related factors, especially temperature-humidity imbalance, is a global challenge. Under such adverse circumstances, desiccation tolerance remains a prime mechanism of several plants and a few animals to escape the hostile consequences of fluctuating hydroperiodicity patterns in their habitats. Among small animals, insects have demonstrated impressive resilience to dehydration and thrive under physiological water deficits without compromising on revival and survival upon rehydration. The focus of this review is to compile research insights on insect desiccation tolerance, gathered over the past several decades from numerous laboratories worldwide working on different insect groups. We provide a comparative overview of species-specific behavioral changes, adjustments in physiological biochemistry and cellular and molecular mechanisms as few of the noteworthy desiccation-responsive survival kits in insects. Finally, we highlight the role of insects as potential mechanistic models in tracking global warming which will form the basis for translational research to mitigate periods of climatic uncertainty predicted for the future.

City limits: Heat tolerance is influenced by body size and hydration state in an urban ant community

“…That said, plasticity in the composition of cuticular hydrocarbons due to desiccation may be limited in ants because CHCs are critical for chemical signaling in this taxon (Martin & Drijfhout, 2009). Related, desiccation may facilitate the allocation of resources from the heat shock response toward other biomolecules associated with desiccation tolerance, such as trehalose, Late Embryonic Abundant proteins, aquaporins, or antioxidants (reviewed in Chown et al, 2011; Thorat & Nath, 2018). Dehydration may also lead to increased catabolism of nutrient reserves (Benoit et al, 2010), which may inhibit an animal's ability to mount a response to heating (Manenti et al, 2018).…”

Spatial variation in early‐winter snow cover determines local dynamics in a network of alpine butterfly populations

“…We suspect that the lack of an interaction between snow cover and extreme low temperatures in the current study is due to temperatures not falling below the critical temperature in those five years, and to the lack of sufficient combinations of temperature and snow cover to detect such interactions. There may be additional benefits of snow cover, beyond its direct effects of protection against extreme cold, such as buffering against complex interactions among desiccation, cold and survival (Elnitsky et al 2008, Thorat and Nath 2018.). Snow cover may also provide benefits for other environmental features such as host plant abundance and distribution (Björk and Molau 2007, Jonas et al 2008).…”

Eco‐genetics of desiccation resistance in Drosophila

“…Nevertheless, insects occupy a wide range of terrestrial micro‐niches ranging from damp environments to deserts. Insects have a variety of sophisticated mechanisms to protect their body against water loss (Thorat & Nath, 2018). Understanding these mechanisms, including at the genetic, molecular and genomic levels, is essential to predict future effects of CC on insect populations, and to allow us to meet future challenges of food security, environmental protection and disease control.…”