scholarly journals The role of the subelytral cavity in water loss in the flightless dung beetle, Circellium bacchus (Coleoptera: Scarabaeinae)

2002 ◽  
Vol 99 (2) ◽  
pp. 253-258 ◽  
Author(s):  
Frances D. DUNCAN
Forests ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
László Somay ◽  
Viktor Szigeti ◽  
Gergely Boros ◽  
Réka Ádám ◽  
András Báldi

Wood pastures are home to a variety of species, including the dung beetle. Dung beetles are an important functional group in decomposition. Specifically, in terms of livestock manure, they not only contribute to nutrient cycling but are key players in supporting human and animal health. Dung beetles, however, are declining in population, and urgent recommendations are needed to reverse this trend. Recommendations need to be based on solid evidence and specific habitats. Herein, we aimed to investigate the role of an intermediate habitat type between forests and pastures. Wood pastures are key areas for dung beetle conservation. For this reason, we compared dung beetle assemblages among forests, wood pastures, and grasslands. We complemented this with studies on the effects of dung type and season at three Hungarian locations. Pitfall traps baited with cattle, sheep, or horse dung were used in forests, wood pastures, and pasture habitats in spring, summer, and autumn. Dung beetle assemblages of wood pastures showed transient characteristics between forests and pastures regarding their abundance, species richness, Shannon diversity, assemblage composition, and indicator species. We identified a strong effect of season and a weak of dung type. Assemblage composition proved to be the most sensitive measure of differences among habitats. The conservation of dung beetles, and the decomposition services they provide, need continuous livestock grazing to provide fresh dung, as well as the maintenance of wood pastures where dung beetle assemblages typical of forests and pastures can both survive.


2021 ◽  
Vol 22 (4) ◽  
pp. 1554
Author(s):  
Tawhidur Rahman ◽  
Mingxuan Shao ◽  
Shankar Pahari ◽  
Prakash Venglat ◽  
Raju Soolanayakanahally ◽  
...  

Cuticular waxes are a mixture of hydrophobic very-long-chain fatty acids and their derivatives accumulated in the plant cuticle. Most studies define the role of cuticular wax largely based on reducing nonstomatal water loss. The present study investigated the role of cuticular wax in reducing both low-temperature and dehydration stress in plants using Arabidopsis thaliana mutants and transgenic genotypes altered in the formation of cuticular wax. cer3-6, a known Arabidopsis wax-deficient mutant (with distinct reduction in aldehydes, n-alkanes, secondary n-alcohols, and ketones compared to wild type (WT)), was most sensitive to water loss, while dewax, a known wax overproducer (greater alkanes and ketones compared to WT), was more resistant to dehydration compared to WT. Furthermore, cold-acclimated cer3-6 froze at warmer temperatures, while cold-acclimated dewax displayed freezing exotherms at colder temperatures compared to WT. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis identified a characteristic decrease in the accumulation of certain waxes (e.g., alkanes, alcohols) in Arabidopsis cuticles under cold acclimation, which was additionally reduced in cer3-6. Conversely, the dewax mutant showed a greater ability to accumulate waxes under cold acclimation. Fourier Transform Infrared Spectroscopy (FTIR) also supported observations in cuticular wax deposition under cold acclimation. Our data indicate cuticular alkane waxes along with alcohols and fatty acids can facilitate avoidance of both ice formation and leaf water loss under dehydration stress and are promising genetic targets of interest.


Author(s):  
J. Binyon

Direct measurement of water loss from isolated podia of Luidia ciliaris under the influence of known levels of hydrostatic pressure has yielded a revised value for the permeability of this structure to water, namely 37.4 x 10-8 cm3/cm2.s.cm H2O pressure. The total fluid loss from a 50 g starfish will therefore be of the order of 0.75 ml/h. The mechanism for the replenishment of this fluid is discussed in the light of the traditional role of the madreporite. It would seem that adequate influx of fluid through this structure has not been observed, neither could it be responsible for ‘topping up’ in the case of arms severed from the parent body which still continue to move for considerable periods.


2018 ◽  
Vol 44 (2) ◽  
pp. 300-312
Author(s):  
Pedro G. da Silva ◽  
Jorge M. Lobo ◽  
Malva Isabel Medina Hernández

2014 ◽  
Vol 369 (1636) ◽  
pp. 20130036 ◽  
Author(s):  
M. Dacke ◽  
Basil el Jundi ◽  
Jochen Smolka ◽  
Marcus Byrne ◽  
Emily Baird

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day.


Icarus ◽  
1984 ◽  
Vol 60 (2) ◽  
pp. 307-316 ◽  
Author(s):  
Steven M. Richardson ◽  
James B. Pollack ◽  
Ray T. Reynolds
Keyword(s):  

2011 ◽  
Vol 243-249 ◽  
pp. 3238-3243
Author(s):  
Zhen Wei Jiang ◽  
Qi Yao Wang

The role of surface water is also the main reason for the formation and development of ground fissures. Five mechanisms were obtained on the formation of ground fissures under the role of surface water in the loess region through theoretical analysis, i.e., fissuring mechanism induced by loess collapsible deformation; that induced by dissolution and suffosion; that induced by water-loss shrinkage; that induced by hydraulic pressure; that induced by humidification and softening. As the role of surface water had certain phased and periodic characteristics, repeated fissuring mechanism of ground fissures was analyzed. Consequently, it could be known that the repeated fissuring of ground fissures under the role of surface water was mainly shown as horizontal openness and closure with little vertical displacement, and fissures were intersected and cross-cut with each other to form a complex network structure.


2012 ◽  
Vol 26 (4) ◽  
pp. 455-457 ◽  
Author(s):  
C. A. DU TOIT ◽  
P. HOLTER ◽  
H. LUTERMANN ◽  
C. H. SCHOLTZ
Keyword(s):  

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