Water Exchange between Insects and Air Moisture

The Water Relations of Insect Cuticle

“…Nevertheless, it seems incontrovertible that a few insects can, at certain times in their life history, extract water from humidities as low as 70, and perhaps even 50 % R.H. (Edney, 1956). The experiments of Lees (1946) and of Browning (1954) infer that water is actually obtained through the cuticle in ticks; this is exceptionally important, for Govaerts & Leclercq (1946) have shown insects to come into equilibrium with a nearly saturated atmosphere over a heavy-water solution so rapidly that the rate of exchange of water with the atmosphere (presumably through the tracheal system) must be very high indeed. Without corroborative evidence, it would be natural to adopt Mellanby's (1932) suggestion that the tracheoles, which are known to have water-absorbing activity, are the site of active uptake.…”

Measurement of Water and Carbon Dioxide Loss From Insects Using Radioactive Isotopes

“…An insect can be labelled with THO by injection or feeding or by exposure to THO vapour, as was done with DHO by Govaerts and Leclercq (1946). Feeding is the simplest method.…”

“…The early use of isotopic water (deuterated water, DHO) to investigate water permeability in animals is outlined by Krogh (1939) and includes an aquatic insect example (Libellula). Isotopic water exchange in terrestrial arthropods was first studied by Govaerts and Leclercq (1946), also using DHO. Subsequently, the availability of radioactive tritiated water (THO) has led to its wide use in investigating permeability in aquatic arthropods (including Smith, 1969;Lockwood et al 1973;Nicolson and Leader, 1974) and also to a number of investigations in terrestrial arthropods (including Wharton and Devine, 1968;Coenen-Staß and Kloft, 1976;Nicolson et al 1984;Appel et al 1986;Machin et al 1992).…”

Effects of temperature, moisture and thermal acclimation on the biology of Tenebrio molitor (Coleoptera: Tenebrionidae)

“…This weight gain reflects an increase in the water content of the body. Govaerts and Leclerq (1946) exposed T. molitor larvae and adults to saturated air containing 8% heavy water. Samples of water extracted from the insect tissues after several hours were shown to contain 8% heavy water indicating that some type of equilibrium between air moisture and tissue water content had been attained.…”