scholarly journals Response to Multiple Stressors: Enhanced Tolerance of Neoseiulus barkeri Hughes (Acari: Phytoseiidae) to Heat and Desiccation Stress through Acclimation

Insects ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 449 ◽  
Author(s):  
Ji Huang ◽  
Ming-Xiu Liu ◽  
Yang Zhang ◽  
Zai-Yin Kuang ◽  
Wei Li ◽  
...  
Keyword(s):  
Biological Control ◽  
High Temperature ◽  
Mortality Rate ◽  
Water Loss ◽  
Loss Rate ◽  
Multiple Stressors ◽  
Mite Species ◽  
Desiccation Stress ◽  
Acclimation Temperature ◽  
C 50

Organisms are always confronted with multiple stressors simultaneously. Combinations of stressors, rather than single stressor, may be more appropriate in evaluating the stress they experience. N. barkeri is one of predatory mite species that are commercialized for controlling spider mites. However, their biological control efficiency was often reduced because of high temperature and desiccation in summer. To understand how to improve the tolerance of N. barkeri to combined heat and desiccation stress, we pre-exposed the adult female of N. barkeri to high temperature, desiccation and high temperature × desiccation stress for acclimation. After proper recovery time, mites were subjected to high temperature × desiccation stress again to detect the acclimation effects. The results are as follows: (1) No decrease in mortality rate were observed under high temperature × desiccation stress after heat acclimation. Instead, it increased significantly with acclimation temperature and time. (2) Dehydration acclimation both at 25 °C and high temperatures reduced mortality rate under high temperature × desiccation stress. Mortality rate was only significantly correlated with the amount of water loss, but not with temperature or water loss rate in acclimation, suggesting the increased tolerance is related to dehydration stress rather than heat stress. Among all acclimations, chronic dehydration at 25 °C, 50% relative humidity were the most effective treatment. This study indicated dehydration acclimation is effective to enhance tolerance of N. barkeri to combined heat and desiccation stress, which can improve the efficiency of biological control under multiple stressors.

scholarly journals Cuticle Hydrocarbons Show Plastic Variation under Desiccation in Saline Aquatic Beetles

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 285
Author(s):  
María Botella-Cruz ◽  
Josefa Velasco ◽  
Andrés Millán ◽  
Stefan Hetz ◽  
Susana Pallarés
Keyword(s):  
Water Loss ◽  
Loss Rate ◽  
Desiccation Stress ◽  
Desiccation Resistance ◽  
Water Beetles ◽  
Physiological Capacity ◽  
Branched Alkanes ◽  
Mediterranean Regions ◽  
Subsequent Exposure ◽  
Acclimation Response

In the context of aridification in Mediterranean regions, desiccation resistance and physiological plasticity will be key traits for the persistence of aquatic insects exposed to increasing desiccation stress. Control of cuticular transpiration through changes in the quantity and composition of epicuticular hydrocarbons (CHCs) is one of the main mechanisms of desiccation resistance in insects, but it remains largely unexplored in aquatic ones. We studied acclimation responses to desiccation in adults of two endemic water beetles from distant lineages living in Mediterranean intermittent saline streams: Enochrus jesusarribasi (Hydrophilidae) and Nebrioporus baeticus (Dytiscidae). Cuticular water loss and CHC composition were measured in specimens exposed to a prior non-lethal desiccation stress, allowed to recover and exposed to a subsequent desiccation treatment. E. jesusarribasi showed a beneficial acclimation response to desiccation: pre-desiccated individuals reduced cuticular water loss rate in a subsequent exposure by increasing the relative abundance of cuticular methyl-branched compounds, longer chain alkanes and branched alkanes. In contrast, N. baeticus lacked acclimation capacity for controlling water loss and therefore may have a lower physiological capacity to cope with increasing aridity. These results are relevant to understanding biochemical adaptations to drought stress in inland waters in an evolutionary and ecological context.

EXPRESS: A Piecewise Model for In Situ Raman Measurement of the Chlorinity of Deep-Sea High-Temperature Hydrothermal Fluids

2021 ◽  
pp. 000370282199911
Author(s):  
meng ge ◽  
Lianfu Li ◽  
Xin Zhang ◽  
Zhendong Luan ◽  
Zengfeng Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Deep Sea ◽  
Okinawa Trough ◽  
Peak Position ◽  
Hydrothermal Fluids ◽  
Calibration Model ◽  
The Okinawa Trough ◽  
Temperature Ranges ◽  
Piecewise Model ◽  
C 50

The chlorinity of deep-sea hydrothermal fluids, representing one of the crucial deep-sea hydrothermal indicators, indicates the degree of deep phase separation of hydrothermal fluids and water/rock reactions. However, accurately measuring the chlorinity of high-temperature hydrothermal fluids is still a significant challenge. In this paper, a piecewise chlorinity model to measure the chlorinity of high-temperature hydrothermal fluids was developed based on the OH stretching band of water, exhibiting an accuracy of 96.20%. The peak position, peak area ratio and F value were selected to establish the chlorinity piecewise calibration model within the temperature ranges of 0-50°C, 50-200°C and 200-300°C. Compared with that of the chlorinity calibration model built based on a single parameter, the accuracy of this piecewise model increased by approximately 4.83-12.33%. This chlorinity calibration model was applied to determine the concentrations of Cl for high-temperature hydrothermal fluids in the Okinawa Trough hydrothermal field.

scholarly journals Differences in Leaf Cuticle Structure and Efficacy among Eastern Redbud and Mexican Redbud Phenotypes

1995 ◽  
Vol 120 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Jimmy L. Tipton ◽  
Marcia White
Keyword(s):  
Leaf Area ◽  
Water Loss ◽  
Loss Rate ◽  
Dry Mass ◽  
Abaxial Surface ◽  
Cercis Canadensis ◽  
Area Basis ◽  
Detached Leaves ◽  
Eastern Redbud ◽  
Mass Basis

The objective of this study was to compare the structure and efficacy in terms of retarding cuticular transpiration of leaf cuticles from eastern redbud (Cercis canadensis L.) and dull-leaf and glossy-leaf Mexican redbud [Cercis canadensis var. mexicana (Rose) M. Hopk.]. Leaves of Mexican redbud exhibited several xeromorphic characteristics compared to eastern redbud: a smaller, thicker leaf with thicker cuticles, more cuticular wax, a higher specific leaf mass, and greater hydrated water content on a leaf area basis. Mexican redbuds with a glossy leaf differed from those with a dull leaf only in a thicker adaxial cuticle lacking wax crystallite on the surface. Epicuticular wax crystallite were present on the abaxial surface of all leaves examined. Detached leaves of eastern redbud had a higher water loss rate than those of Mexican redbud only on a dry mass basis, not on a leaf area basis. There was no difference in the rate of water loss by detached leaves of glossy-leaf and dull-leaf Mexican redbuds after 4 hours.

scholarly journals IMPACT OF FIBER DIAMETER ON-ROAD PERFORMANCE OF CEMENT-STABILIZED MACADAM

2017 ◽  
Vol 12 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Zhijun Liu ◽  
Dongquan Wang ◽  
Xiaobi Wei ◽  
Liangliang Wang
Keyword(s):  
Water Loss ◽  
Loss Rate ◽  
Surface Effect ◽  
Fiber Diameter ◽  
Base Material ◽  
The Road ◽  
Water Loss Rate ◽  
Reinforced Cement ◽  
Road Performance ◽  
The Impact

Cement-stabilized macadam is the most widely used road base material in road engineering. The current study investigated the impact of fiber diameter on its performance. The authors prepared polyester fibers with diameters of 20, 35, 70, and 105 μm and added them to cement-stabilized macadam. Then, the indoor shrinkage tests and mechanical property tests at different ages were conducted. Then, the property changes of the polyester-reinforced cement-stabilized macadam were analysed. The water loss rate of the polyester-reinforced cement-stabilized macadam is subject to the combined influence of the “water loss surface effect” and “water loss porthole effect.” With increasing fiber diameter, the water loss surface effect becomes stronger, and the water loss porthole effect gradually decreases; thus, the overall effect transitions from the latter to the former. Moreover, the water loss rate shows an increasing trend of decreasing to its minimum. Therefore, with increasing fiber diameter, the average dry shrinkage coefficient of the polyester-reinforced cement-stabilized macadam first increases and then decreases, while the temperature shrinkage coefficients increase. The change in the fiber diameter does not significantly affect the compressive resilient modulus of the polyester-reinforced cement-stabilized macadam if the fiber content remains constant. These findings demonstrate the functional mechanism of the fiber diameter on the road performance of cement-stabilized macadam, thus improving our understanding of the road performance of the polyester-reinforced cement-stabilized macadam and laying a solid theoretical foundation for its many applications.

Effect of CeCl3-Containing Flux on Microstructure and Mechanical Properties of Mg Alloy Containing Rare Earth

2007 ◽  
Vol 546-549 ◽  
pp. 563-566
Author(s):  
Wen Jiang Ding ◽  
Guo Hua Wu ◽  
Bong Sun You ◽  
Dong Yim Chang
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Loss Rate ◽  
Alloy Element ◽  
Corrosion Properties ◽  
High Temperature Mechanical Properties ◽  
Β Phase ◽  
Element Loss

The effects of CeCl3-containing fluxes on RE element loss, the high temperature mechanical properties, microstructure and corrosion properties of magnesium alloy containing RE have been studied. The results showed that a certain amount of CeCl3 in purification fluxes restrained the reaction between the Ce element and fluxes to decrease the loss of Ce in alloys. With the flux containing 9% CeCl3, the loss rate of alloy element Ce can be reduced from 26.9% to 3.4%, and the σb and δ of the alloys at 150°C counld be improved from 160.9MPa and 6.2% to 176.5MPa and 7.9% compared with that of conventional MgCl2-containing flux , respectively. Besides, the coarse β phase and rod-like RE phase were refined effectively by CeCl3-containing fluxes.

Using laboratory selection for desiccation resistance to examine the relationship between respiratory pattern and water loss in insects.

1998 ◽  
Vol 201 (21) ◽  
pp. 2945-2952 ◽  
Author(s):  
A E Williams ◽  
M R Rose ◽  
T J Bradley
Keyword(s):  
Drosophila Melanogaster ◽  
Water Loss ◽  
Loss Rate ◽  
Respiratory Pattern ◽  
Desiccation Resistance ◽  
Water Loss Rate ◽  
Laboratory Selection ◽  
Selection For ◽  
The Relationship ◽  
Co2 Release

We conducted concurrent measurements of rates of CO2 and H2O release from individual fruit flies Drosophila melanogaster taken from populations subjected to three different selective regimes: (1) populations selected for resistance to desiccation (D flies); (2) populations maintained as their controls (C flies); and (3) the ancestral populations of the D and C populations (O flies). In the D flies, water loss rates were significantly reduced, the standard error of the regression (SER) of the CO2 release pattern measured over the survival period of the flies was increased, and the ratio of CO2 loss to H2O loss (VCO2/VH2O) was increased. Correlations across all 15 populations from the three selection treatments indicate that survival time was negatively correlated with water loss rate, positively correlated with the SER of CO2 release and positively correlated with the VCO2/VH2O ratio. We did not, however, find a significant correlation between the SER of CO2 release and rates of water loss or the VCO2/VH2O ratio.

The effect of respiratory pattern on water loss in desiccation-resistant Drosophila melanogaster.

1998 ◽  
Vol 201 (21) ◽  
pp. 2953-2959 ◽  
Author(s):  
A E Williams ◽  
T J Bradley
Keyword(s):  
Drosophila Melanogaster ◽  
Water Loss ◽  
Loss Rate ◽  
Extended Period ◽  
Peak Height ◽  
Respiratory Pattern ◽  
Water Loss Rate ◽  
Selection For ◽  
Reduced Water ◽  
Co2 Release

We measured CO2 and H2O release from individual fruit flies from five populations of Drosophila melanogaster selected for resistance to desiccation (D flies). Our previous work found that these flies survive for an extended period in dry air, have an increase in the peak height and frequency of CO2 release, as measured by the standard error of a linear regression (SER) of CO2 release for the entire survival period, and have reduced water loss rates (VH2O) compared with their control or ancestor populations. In the present study, we examined the following respiratory characteristics: VCO2, VH2O, the SER of CO2 release and the ratio of VCO2 to VH2O in the D flies. Correlations between these characters were calculated in order to determine the effect of respiratory pattern on water loss. We found that, within the D flies, neither periodic release of CO2 nor an increased SER for CO2 release was associated with reduced water loss. In addition, an increased SER was positively correlated with both an increased water loss rate and a decreased survival time. Therefore, although selection for desiccation resistance leads to both an increased SER and a decreased rate of water loss in the D flies, the increased SER does not significantly reduce respiratory water loss.

Predation, prey preference and reproduction of predatory mites Amblydromalus limonicus (Garman), Amblyseius herbicolus (Chant) and Neoseiulus cucumeris (Oudemans) (Mesostigmata: Phytoseiidae) on immature Sericothrips staphylinus Haliday (Thysanoptera: Thripidae), a biocontrol agent of gorse

2019 ◽  
Vol 24 (3) ◽  
pp. 508
Author(s):  
Wendy Lam ◽  
Quentin Paynter ◽  
Zhi-Qiang Zhang
Keyword(s):  
Biological Control ◽  
New Zealand ◽  
Choice Experiment ◽  
Biocontrol Agent ◽  
Predation Rate ◽  
Mite Species ◽  
Oviposition Rate ◽  
Neoseiulus Cucumeris ◽  
Amblydromalus Limonicus ◽  
Amblyseius Herbicolus

Gorse, Ulex europaeus, is an invasive weed that has serious agricultural, economic and ecological impacts. Although various biological control agents have been released in New Zealand, these have showed no noticeable impact on gorse populations. One such agent, Sericothrips staphylinus, was introduced to New Zealand in 1990 and although laboratory impact studies indicated it was a highly promising gorse biological control agent, it has not been as effective as was hoped. We hypothesized this was due to predation by natural enemies. This study investigated the predation and oviposition rates of three phytoseiid mites (Amblydromalus limonicus, Amblyseius herbicolus, and Neoseiulus cucumeris) that have been found on gorse plants in New Zealand on three S. staphylinus stages (1st instar larvae, 2nd instar larvae, and prepupa) in both choice and non-choice conditions. In non-choice conditions, A. limonicus had the highest predation and oviposition rate across all three immature stages, and N. cucumeris had the lowest. Amblydromalus  limonicus, A. herbicolus, and N. cucumeris all had their highest predation rate when consuming 1st instar larvae, and their lowest predation rate when consuming prepupa. In the choice experiment, all three predatory mite species consumed their highest proportion of 1st instar larvae, and their lowest proportion of prepupae.  The oviposition rate of all three mite species in the choice experiment was similar to the oviposition rate when presented with 1st instar larvae only. The results from this study confirm that A. limonicus, A. herbicolus, and N. cucumeris can predate and reproduce on S. staphylinus 1st instar larvae, 2nd instar larvae, and prepupa. This indicates that predation may be the reason why S. staphylinus is an ineffective biocontrol agent in New Zealand. 

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