scholarly journals Respiratory Strategies in Relation to Ecology and Behaviour in Three Diurnal Namib Desert Tenebrionid Beetles

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1036
Author(s):  
Frances D. Duncan
Keyword(s):  
Gas Exchange ◽  
Water Loss ◽  
Evaporative Cooling ◽  
Respiratory Physiology ◽  
Metabolic Rates ◽  
Beetle Species ◽  
Water Droplets ◽  
Namib Desert ◽  
Flow Through

The respiratory physiology of three diurnal ultraxerophilous tenebrionid beetles inhabiting either the dune slipface or gravel plain in the Namib Desert was investigated. The role of the mesothoracic spiracles and subelytral cavity in gas exchange was determined by flow-through respirometry. All three species exhibited the discontinuous gas exchange cycles with a distinct convection based flutter period and similar mass specific metabolic rates. There was variation in their respiration mechanics that related to the ecology of the species. The largest beetle species, Onymacris plana, living on the dune slipface, has a leaky subelytral cavity and used all its spiracles for gas exchange. Thus, it could use evaporative cooling from its respiratory surface. This species is a fog harvester as well as able to replenish water through metabolising fats while running rapidly. The two smaller species inhabiting the gravel plains, Metriopus depressus and Zophosis amabilis, used the mesothoracic spiracles almost exclusively for gas exchange as well as increasing the proportional length of the flutter period to reduce respiratory water loss. Neither species have been reported to drink water droplets, and thus conserving respiratory water would allow them to be active longer.

CO2 release patterns in Drosophila melanogaster: the effect of selection for desiccation resistance.

1997 ◽  
Vol 200 (3) ◽  
pp. 615-624 ◽  
Author(s):  
A E Williams ◽  
M R Rose ◽  
T J Bradley
Keyword(s):  
Drosophila Melanogaster ◽  
Gas Exchange ◽  
Desiccation Resistance ◽  
Strongly Correlated ◽  
Dry Air ◽  
Flow Through ◽  
Selection For ◽  
The Relationship ◽  
Co2 Release

We used laboratory natural selection on insects as a means of investigating the role of patterns of gas exchange in desiccation resistance. We used 15 populations of Drosophila melanogaster: five selected for desiccation resistance, five control populations and five ancestral populations. Using flow-through respirometry, we found that D. melanogaster from all populations produced irregular peaks of CO2 release. To quantify the height and frequency of these peaks, we used the standard error of a linear regression (SER) through the recordings of CO2 release. The values for the SER were significantly larger in the populations selected for desiccation resistance than in the control and ancestral populations. Occasionally, highly periodic peaks of CO2 release were observed in the desiccation-resistant populations only. Maximum SER was found to be strongly correlated with survival time in dry air among selection treatments, but not among individuals within a population. Access to dietary water resulted in lower SER values. These data demonstrate that gas exchange is physiologically controlled in Drosophila melanogaster and that the pattern of gas exchange can change under selection. The relationship between these CO2 release patterns and classic discontinuous ventilation is discussed.

Ant breathing: testing regulation and mechanism hypotheses with hypoxia

1995 ◽  
Vol 198 (7) ◽  
pp. 1613-1620 ◽  
Author(s):  
J Lighton ◽  
D Garrigan
Keyword(s):  
Gas Exchange ◽  
Water Loss ◽  
Negative Pressure ◽  
Co2 Emission ◽  
Nitrogen Accumulation ◽  
Phase Duration ◽  
O2 Concentration ◽  
Flow Through ◽  
Discontinuous Gas Exchange Cycle ◽  
And Function

Using normoxic and hypoxic flow-through respirometry, we investigated the regulation of the closed-spiracle (C) and the nature of the fluttering-spiracle (F) phases of the discontinuous gas-exchange cycle (DGC) of the ant Camponotus vicinus. We predicted that as ambient O2 concentrations declined, DGC frequency would increase, because C phase duration would decrease (reflecting earlier hypoxic initiation of the F phase) and F phase duration would shorten (reflecting nitrogen accumulation), if convective mass inflow caused by a negative pressure gradient across the spiracles, rather than by diffusion, is the dominant F phase gas-exchange mechanism. C phase duration decreased with declining ambient O2 concentrations, as predicted. In contrast, DGC frequency decreased and F phase duration increased with decreasing ambient O2 concentrations. This was opposite to the expected trend if gas exchange in the F phase was mediated by convection, as is generally hypothesized. We therefore cannot disprove that F phase gas exchange was largely or purely diffusion-based. In addition, our data show equivalent molar rates of H2O and CO2 emission during the F phase. In contrast, during the open-spiracle phase, the duration of which was not affected by ambient O2 concentration, far more H2O than CO2 was lost. We discuss these findings and suggest that current hypotheses of F phase gas-exchange mechanisms and function in reducing respiratory water loss in adult insects may require revision.

scholarly journals Intra-individual variation allows an explicit test of the hygric hypothesis for discontinuous gas exchange in insects

2009 ◽  
Vol 6 (2) ◽  
pp. 274-277 ◽  
Author(s):  
Caroline M. Williams ◽  
Shannon L. Pelini ◽  
Jessica J. Hellmann ◽  
Brent J. Sinclair
Keyword(s):  
Carbon Dioxide ◽  
Gas Exchange ◽  
Metabolic Rate ◽  
Water Loss ◽  
Individual Variation ◽  
Loss Reduction ◽  
Total Water ◽  
Explicit Test ◽  
Carbon Dioxide Release ◽  
Flow Through

The hygric hypothesis postulates that insect discontinuous gas exchange cycles (DGCs) are an adaptation that reduces respiratory water loss (RWL), but evidence is lacking for reduction of water loss by insects expressing DGCs under normal ecological conditions. Larvae of Erynnis propertius (Lepidoptera: Hesperiidae) naturally switch between DGCs and continuous gas exchange (CGE), allowing flow-through respirometry comparisons of water loss between the two modes. Water loss was lower during DGCs than CGE, both between individuals using different patterns and within individuals using both patterns. The hygric cost of gas exchange (water loss associated with carbon dioxide release) and the contribution of respiratory to total water loss were lower during DGCs. Metabolic rate did not differ between DGCs and CGE. Thus, DGCs reduce RWL in E. propertius , which is consistent with the suggestion that water loss reduction could account for the evolutionary origin and/or maintenance of DGCs in insects.

scholarly journals 717 PB 423 ETHYLENE DEGASSING OF GRAPEFRUIT

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 535g-536
Author(s):  
Peter D. Petracek
Keyword(s):  
Gas Exchange ◽  
Silicone Rubber ◽  
Water Loss ◽  
Fruit Color ◽  
Water Soluble ◽  
Chlorophyll Degradation ◽  
Initial Exposure ◽  
Early Season ◽  
Flow Through

Early-season fresh citrus are routinely exposed to ethylene to trigger chlorophyll degradation (degreening) in the peel and thus improve fruit color. Recent questions about whether ethylene is trapped in the fruit by subsequent waxing have sparked interest in characterizing ethylene exchange. Internal gas samples of mature, pesticide-free `White Marsh' grapefruit were taken through septa of silicone rubber on electrical tape affixed 10 the blossom end. Gassing of the fruit in a degreening room (10 ppm ethylene) required about four hours lo reach equilibrium while degassing was completed in less than two hours and was not affected by location of the fruit in a 0.680 m3 pallet bin. Waxing with a water-soluble wax immediately following ethylene exposure increased the time for complete degassing to over 48 h. Surface gas exchange protiles were prepared by sequentially analyzing the same fruit after: (1) harvest, (2) 22 h exposure to 10 ppm ethylene, (3) exposure to ethylene and washing with an ionic cleaning surfactant, and (4) exposure to ethylene and waxing. Glass cells with interfacing silicone rubber o-rings (23 mm diam.) were strapped to the fruit following each treatment. Ethylene emanation was measured by sampling the cells which were capped 15 m after removal from ethylene. Water and CO2 were measured by flow-through cells following ethylene analysis. Ethylene emanation following the initial exposure was the same for the stem end and midsection and two fold greater than the blossom end. Washing increased the rate of emanation five fold for the stem end and about 2.5 fold for the midsection and blossom end. Waxing reduced emanation by nearly four fold for the midsection and blossom end, but only 30% for the stem end. Water loss was increased about 40% by washing, reduced about 30% by waxing, and was primarily through the stem end. Stem-end CO2 exchange doubled upon waxing.

Effects of lipid phase transitions on cuticular permeability: model membrane and in situ studies

1999 ◽  
Vol 202 (22) ◽  
pp. 3255-3262 ◽  
Author(s):  
B.C. Rourke ◽  
A.G. Gibbs
Keyword(s):  
Water Loss ◽  
Model Membranes ◽  
Lipid Phase ◽  
Transition Temperatures ◽  
Permeability Model ◽  
Lipid Phase Transitions ◽  
Cuticular Permeability ◽  
Flow Through ◽  
Highly Correlated

The role of lipid physical properties in cuticular water loss was examined in model membranes and intact insects. In model experiments, pure hydrocarbons of known melting point (T(m)) were applied to a membrane, and the effects of temperature on permeability were quantified. Arrhenius plots of permeability were biphasic, and transition temperatures for water loss (T(c)) were similar to T(m). In grasshoppers Melanoplus sanguinipes, changes in cuticular water loss were measured using flow-through respirometry. Transition temperatures were determined and compared with T(m) values of cuticular lipids, determined using Fourier transform infrared spectroscopy, for the same individuals. Individual variation in T(m) was highly correlated with T(c), although T(m) values were slightly higher than T(c) values. Our results show that, in both intact insects and model membranes, lipid melting results in greatly increased cuticular permeability.

scholarly journals Tracheal compression in pupae of the beetle Zophobas morio

2015 ◽  
Vol 11 (6) ◽  
pp. 20150259 ◽  
Author(s):  
Hodjat Pendar ◽  
Melissa C. Kenny ◽  
John J. Socha
Keyword(s):  
Gas Exchange ◽  
X Rays ◽  
Metabolic Rates ◽  
Tracheal System ◽  
Tracheal Compression ◽  
Major Function ◽  
The Status ◽  
Tracheal Collapse ◽  
Abdominal Movement

Insects that are small or exhibit low metabolic rates are considered to not require active ventilation to augment diffusive gas exchange. Some pupae with low metabolic rates exhibit abdominal pumping, a behaviour that is known to drive tracheal ventilation in the adults of many species. However, previous work on pupae suggests that abdominal pumping may serve a non-respiratory role. To study the role of abdominal pumping in pupa of the beetle Zophobas morio , we visualized tracheal dynamics with X-rays while simultaneously measuring haemolymph pressure, abdominal movement, and CO 2 emission. Pupae exhibited frequent tracheal compressions that were coincident with both abdominal pumping and pulsation of pressure in the haemolymph. However, more than 63% of abdominal pumping events occurred without any tracheal collapse and hence ventilation, suggesting that the major function of the abdominal pump is not respiratory. In addition, this study shows that the kinematics of abdominal pumping can be used to infer the status of the spiracles and internal behaviour of the tracheal system.

scholarly journals Evaporative Cooling in the Desert Cicada: Thermal Efficiency and Water*sol;Metabolic Costs

1991 ◽  
Vol 159 (1) ◽  
pp. 269-283
Author(s):  
NEIL F. HADLEY ◽  
MICHAEL C. QUINLAN ◽  
MICHAEL L. KENNEDY
Keyword(s):  
Body Temperature ◽  
Gas Exchange ◽  
Water Loss ◽  
Thermal Efficiency ◽  
Evaporative Cooling ◽  
Water Flux ◽  
Simultaneous Measurements ◽  
Metabolic Costs ◽  
Hydration State

Using plant xylem water for evaporative cooling, the desert cicada Diceroprocta apache can maintain a body temperature as much as 5°C below ambient (Ta=42°C). Simultaneous measurements of water loss and gas exchange for cicadas feeding on perfused twigs show substantial increases in transpiration at temperatures at which evaporative cooling begins (between 37 and 38°C), but only modest increases in Vo2 and Vco2. The extent and duration of evaporative cooling depend on the cicada's hydration state and the rate of water flux from cuticular pores located on the surface of the thorax and abdomen.

scholarly journals Slow Discontinuous Ventilation in the Namib Dune-sea Ant Camponotus Detritus (Hymenoptera, Formicidae)

1990 ◽  
Vol 151 (1) ◽  
pp. 71-82 ◽  
Author(s):  
JOHN R. LIGHTON
Keyword(s):  
Body Size ◽  
Gas Exchange ◽  
Water Loss ◽  
Ventilation Rate ◽  
Co2 Production ◽  
Namib Desert ◽  
Ventilation Frequency ◽  
Loss Rates

Data on discontinuous ventilation phenomena in Camponotus detritus (Emery), an ant from the hyper-arid Namib Desert, are described and compared to equivalent data from two mesic insects, including Camponotus vicinus (Mayr). Although rate of CO2 production (Vco2 and body size were equivalent in C. detritus and C. vicinus, the ventilation rate of C. detritus was fourfold lower, significantly reducing predicted respiratory water loss rates. Ventilation rate was presumably modulated by Vco2, and low ventilation frequency was maintained in part by significant gas exchange during the fluttering-spiracle phase of the ventilation cycle, which is generally characterized by low rates of respiratory water loss.

Role of Histamine and Leucotaxin in Function of Cellular Defense Mechanism

1956 ◽  
Vol 184 (2) ◽  
pp. 296-300 ◽  
Author(s):  
László Kátó ◽  
Béla Gözsy
Keyword(s):  
Fluid Flow ◽  
Tissue Damage ◽  
Inflammatory Process ◽  
Defense Mechanism ◽  
Volatile Oils ◽  
Time Intervals ◽  
Cellular Defense ◽  
Intradermal Administration ◽  
Flow Through

Experiments are presented to the effect that in an inflammatory process histamine and leucotaxin appear successively at different and orderly time intervals, thus assuring an increased fluid flow through the capillary wall. Histamine is released not only in the inflammatory process but also by intradermal administration of such substances (volatile oils or their components) which induce neither the triple response of Th. Lewis nor any tissue damage. This could be explained by the fact that in the tissues histamine is ‘present’ but leucotaxin is ‘formed.’

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