scholarly journals Relationships between the Pathogen Erysiphe alphitoides, the Phytophagous Mite Schizotetranychus garmani (Acari: Tetranychidae) and the Predatory Mite Euseius finlandicus (Acari: Phytoseiidae) in Oak

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 981
Author(s):  
Slobodan Milanović ◽  
Katarina Mladenović ◽  
Bojan Stojnić ◽  
Alejandro Solla ◽  
Ivan Milenković ◽  
...  
Keyword(s):  
Body Size ◽  
Powdery Mildew ◽  
Population Density ◽  
The Body ◽  
Pedunculate Oak ◽  
Adult Size ◽  
Phytophagous Mite ◽  
Euseius Finlandicus ◽  
Erysiphe Alphitoides ◽  
The Impact

Food webs on forest trees include plant pathogens, arthropods, and their natural enemies. To increase the understanding of the impact of a plant pathogen on herbivore-natural enemy interactions, we studied the powdery mildew fungus Erysiphe alphitoides, the phytophagous mite Schizotetranychus garmani, and the predatory and mycophagous mite Euseius finlandicus in pedunculate oak (Quercus robur) leaves. In June, July and August of 2016, we assessed the severity of powdery mildew, mite population density and adult female mite size in 30 trees in three forests near Belgrade, Serbia. In August, the infection severity of E. alphitoides related positively to the population density of S. garmani and negatively to the body size of S. garmani females. Throughout the vegetative season, the infection severity of E. alphitoides related positively to the population density of E. finlandicus but not to its body size. The effect of E. alphitoides on the population density and adult size of S. garmani was not mediated by the population density of E. finlandicus, and vice versa. Interactions were consistent in all forests and varied with the summer month. Our findings indicate that E. alphitoides can influence the average body size and population densities of prey and predatory mites studied, irrespective of predator-prey relationships.

scholarly journals Exploring the Role of Insulin Signaling in Relative Growth: A Case Study on Wing-Body Scaling in Lepidoptera

2019 ◽  
Vol 59 (5) ◽  
pp. 1324-1337 ◽  
Author(s):  
Kenneth Z McKenna ◽  
Della Tao ◽  
H Frederik Nijhout
Keyword(s):  
Body Size ◽  
Insulin Signaling ◽  
The Body ◽  
Adult Size ◽  
Tor Signaling ◽  
Relative Growth ◽  
Laboratory Populations ◽  
Body Sizes ◽  
Specific Variation ◽  
Wing Growth

Abstract Adult forms emerge from the relative growth of the body and its parts. Each appendage and organ has a unique pattern of growth that influences the size and shape it attains. This produces adult size relationships referred to as static allometries, which have received a great amount of attention in evolutionary and developmental biology. However, many questions remain unanswered, for example: What sorts of developmental processes coordinate growth? And how do these processes change given variation in body size? It has become increasingly clear that nutrition is one of the strongest influences on size relationships. In insects, nutrition acts via insulin/TOR signaling to facilitate inter- and intra-specific variation in body size and appendage size. Yet, the mechanism by which insulin signaling influences the scaling of growth remains unclear. Here we will discuss the potential roles of insulin signaling in wing-body scaling in Lepidoptera. We analyzed the growth of wings in animals reared on different diet qualities that induce a range of body sizes not normally present in our laboratory populations. By growing wings in tissue culture, we survey how perturbation and stimulation of insulin/TOR signaling influences wing growth. To conclude, we will discuss the implications of our findings for the development and evolution of organismal form.

Primary productivity, deoxygenation, and the Gulliver-absence effect determine bivalve body size following the end-Permian mass extinction

2020 ◽  
Author(s):  
Melanie Tietje ◽  
William J. Foster ◽  
Jana Gliwa ◽  
Clara Lembke ◽  
Autumn Pugh ◽  
...  
Keyword(s):  
Body Size ◽  
Ocean Circulation ◽  
Mass Extinction ◽  
The Body ◽  
Large Species ◽  
Mass Extinctions ◽  
Shell Size ◽  
Body Sizes ◽  
Permian Mass Extinction ◽  
The Impact

<p> The impact of mass extinctions on the body sizes of animals has received considerable attention and debate, as to whether the reduced size of post-extinction organisms is due to the selective extinction of large species, absence of large species as a stochastic effect of low-diversity faunas, or a size decrease within surviving genera and species. Here, we investigated the body sizes of bivalves following the end-Permian mass extinction event and show that the shell size increase of bivalve genera was driven by both evolutionary and ecophenotypic responses. First, some genera show significant increases in body size with the evolution of new species. Further, the same genera record significant within-species increases in average and maximum body size into the late Induan, indicating that ecophenotypic changes were also involved on long-term body size trends. These increases are associated with invigorated ocean circulation, improved oxygenation of the seafloor, and probably increased food supply.</p>

scholarly journals Antler and Body Size in Black-Tailed Deer: An Analysis of Cohort Effects

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Johanna C. Thalmann ◽  
R. Terry Bowyer ◽  
Ken A. Aho ◽  
Floyd W. Weckerly ◽  
Dale R. McCullough
Keyword(s):  
Body Size ◽  
Population Density ◽  
Odocoileus Hemionus ◽  
The Body ◽  
Cohort Effects ◽  
Odocoileus Hemionus Columbianus ◽  
Extrinsic Factors ◽  
Large Herbivores ◽  
Female Population ◽  
Antler Size

For long-lived species, environmental factors experienced early in life can have lasting effects persisting into adulthood. Large herbivores can be susceptible to cohort-wide declines in fitness as a result of decreases in forage availability, because of extrinsic factors, including extreme climate or high population densities. To examine effects of cohort-specific extrinsic factors on size of adults, we performed a retrospective analysis on harvest data of 450 male black-tailed deer (Odocoileus hemionus columbianus) over 19 years in central California, USA. We determined that population density of females had a more dominant effect than did precipitation on body size of males. Harvest of female deer resulted in increases in the overall size of males, even though a 6-year drought occurred during that treatment period. Body size was most influenced by female population density early in life, while antler size was highly affected by both weather early in life and the year directly before harvest. This study provides insights that improve our understanding of the role of cohort effects in body and antler size by cervids; and, in particular, that reduction in female population density can have a profound effect on the body and antler size of male deer.

scholarly journals Decomposing phenotypic skew and its effects on the predicted response to strong selection

2021 ◽  
Author(s):  
Joel L Pick ◽  
Hannah Lemon ◽  
Caroline Elizabeth Thomson ◽  
Jarrod Hadfield
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Quantitative Genetics ◽  
Selection Response ◽  
Evolutionary Change ◽  
Directional Selection ◽  
The Body ◽  
Cyanistes Caeruleus ◽  
The Impact ◽  
Blue Tits

The major frameworks for predicting evolutionary change assume that a phenotype's underlying genetic and environmental components are normally distributed. However, the predictions of these frameworks may no longer hold if distributions are skewed. Despite this, phenotypic skew has never been decomposed, meaning the fundamental assumptions of quantitative genetics remain untested. Here, we demonstrate that the substantial phenotypic skew in the body size of juvenile blue tits (Cyanistes caeruleus) is driven by environmental factors. Although skew had little impact on our predictions of selection response in this case, our results highlight the impact of skew on the estimation of inheritance and selection. Specifically, the non-linear parent-offspring regressions induced by skew, alongside selective disappearance, can strongly bias estimates of heritability. The ubiquity of skew and strong directional selection on juvenile body size implies that heritability is commonly overestimated, which may in part explain the discrepancy between predicted and observed trait evolution.

scholarly journals Comparative studies on storage cells in tardigrades during starvation and anhydrobiosis

2010 ◽  
Vol 56 (2) ◽  
pp. 259-263 ◽  
Author(s):  
Andy Reuner ◽  
Steffen Hengherr ◽  
Franz Brümmer ◽  
Ralph O. Schill
Keyword(s):  
Body Size ◽  
Cell Size ◽  
Green Algae ◽  
Comparative Studies ◽  
Body Cavity ◽  
The Body ◽  
The Other ◽  
Nutrient Regime ◽  
Storage Cells ◽  
The Impact

Abstract The impact of starvation and anhydrobiosis on the number and size of the storage cells in the tardigrade species Milnesium tardigradum, Paramacrobiotus tonollii and Macrobiotus sapiens was investigated to gain more insight on the energetic side of anhydrobiosis. Storage cells are free floating cells within the body cavity of tardigrades and are presumed to store and release energy in form of glycogen, protein and fat to maintain a constant nutrient regime for the other tissues. The body size of the animals was not correlated with the size of the storage cells, however, M. tardigradum the largest species analysed also had the largest storage cells. A reduction in the size of the storage cells is apparent in all three species after seven days of starvation. A seven-day period of anhydrobiosis leads to a decrease in cell size in M. tardigradum but not in P. tonollii and M. sapiens. Although M. sapiens was raised on green algae, and M. tardigradum and P. tonollii were fed with rotifers and nematodes this difference in nourishment was not reflected in the response of the storage cells to anhydrobiosis.

scholarly journals Occurrence of Erysiphe alphitoides in oak stands affected by flood disaster

2015 ◽  
Vol 76 (1) ◽  
pp. 73-77
Author(s):  
Wojciech Szewczyk ◽  
Robert Kuźmiński ◽  
Małgorzata Mańka ◽  
Hanna Kwaśna ◽  
Piotr Łakomy ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Statistical Significance ◽  
Carbon Assimilation ◽  
Stress Factors ◽  
Deciduous Tree ◽  
Pedunculate Oak ◽  
Oak Decline ◽  
Tree Vitality ◽  
Erysiphe Alphitoides ◽  
Assimilation Capacity

Abstract Pedunculate oak (Quercus robur L.) is the most valuable deciduous tree species in Poland. For almost 30 years, an oak decline resulting from stress factors leading to a decrease of tree vitality in the long-term has been observed. The aim of the present study was to determine the proportion of leaves infected by the fungus Erysiphe alphitoides, the cause of powdery mildew, in post-flood oak stands situated in the Forest District Wołów (51°32’N, 16°62’E) as well as to evaluate effects of powdery mildew with respect to the oak decline. In order to record the powdery mildew incidence, we selec ted three trees in each of the ten investigated oak stands, and 200 leaves were collected from the upper part of the crowns. The percentage of infected leaves as well as the reduction of carbon assimilation capacity was assessed. Furthermore, we evaluated the average reduction of carbon assimilation capacity and the percentage of withering branch tips in 25 adjacent trees. Incidences of powdery mildew were observed in seven out of the ten stands. The maximum tree damage did not exceed 22% leaf infection and mean defoliation within the study areas ranged from 18% to 61.4%. Non-withering branch tips were observed in one post-flood area as well as in one area situated outside the flooded region. Within the remaining areas studied, the average proportion of withering branch tips ranged from 0.4% to 13.8%. Statistical analyses showed that differences between the investigated stands with regard to the rate of powdery mildew occurrence were not significant. Correlating the means, however, revealed a relationship between powdery mildew incidence and branch tip withering. This relationship is a possible indication of the ongoing oak dieback. No statistically significant relationship between tree defoliation and powdery mildew incidence was found. The lack of statistical significance, as observed here, implies that water stagnation within the investigated stands had no effect on Erysiphe alphitoides infection.

scholarly journals Possibility to change the body size in worker bees by a combination of small-cell and standard-cell combs in the same nest

Apidologie ◽  
2021 ◽  
Author(s):  
Piotr Dziechciarz ◽  
Grzegorz Borsuk ◽  
Krzysztof Olszewski
Keyword(s):  
Body Size ◽  
Fill Factor ◽  
Small Cell ◽  
The Body ◽  
Width Ratio ◽  
Standard Cell ◽  
Morphometric Traits ◽  
Cell Width ◽  
Honeybee Subspecies ◽  
The Impact

AbstractThe aim of the study was to investigate the impact of the combination of the colony type (kept on small-cell or standard-cell combs) and the width of worker comb cells (small-cell or standard-cell combs) on the body weight and morphometric traits of worker bees. The values of morphometric parameters of worker bees changed within a substantially lower range than the width of their rearing cells. This indicates that the worker body size is relatively constant, and manipulation with the cell width is not a good method for modeling the body size of workers. The reduction in the thorax weight was proportional to the decrease in the comb cell width, and this part of the body proved to be most susceptible to weight reduction caused by the use of small-cell combs. The rearing of workers in small-cell combs in the colony kept on standard-cell combs resulted in an increase in the value of the fill factor (thorax width to cell width ratio). The relatively constant body size of workers in combination with the use of small-cell combs resulting in an increase in the fill factor may be one of the determinants of increased resistance of the insects to Varroa destructor. The values of the morphometric traits commonly used for identification of honeybee subspecies, i.e., the length of the fore wing, the sum of the widths of 3rd and 4thth tergites, and the proboscis length, were inconsiderably altered vs. the changes in the comb cell width, which confirms their high suitability for identification of honeybee subspecies.

Regional analysis of body size and population density in stream fish assemblages: testing predictions of the energetic equivalence rule

2002 ◽  
Vol 59 (8) ◽  
pp. 1350-1360 ◽  
Author(s):  
Jason H Knouft
Keyword(s):  
Body Size ◽  
Population Density ◽  
Density Distribution ◽  
Fish Assemblages ◽  
The Body ◽  
Bergmann’S Rule ◽  
Stream Fish ◽  
Bergmann's Rule ◽  
Size Population ◽  
Stream Fish Assemblages

The energetic equivalence rule predicts that body mass (W) and population density (β) within an assemblage are negatively correlated and will exhibit a W–0.75 = β relationship. Bergmann's rule predicts that body size among species will increase with increasing latitude. If species body size increases with latitude, the shape of the body size – population density distribution among assemblages may also vary. This change in the body size – population density distribution, when viewed in the context of the energetic equivalence rule, may indicate an alteration in the use of available energy by individuals of different sizes within an assemblage. Twenty-eight streams were sampled across four geographically distinct regions to determine if stream fish assemblages conform to the prediction of the energetic equivalence rule. Body size in stream fish assemblages did not support the pattern predicted by Bergmann's rule, but rather was negatively correlated with latitude. Stream fish assemblages generally did not conform to the relationship predicted by the energetic equivalence rule. Moreover, these results, coupled with the predictions of the energetic equivalence rule, suggest that larger individuals tended to control a disproportionately greater amount of energy than smaller individuals in stream fish assemblages, which may be partially due to predation pressure on smaller individuals.

scholarly journals The timing and asymmetry of plant–pathogen–insect interactions

2020 ◽  
Vol 287 (1935) ◽  
pp. 20201303
Author(s):  
Laura J. A. van Dijk ◽  
Johan Ehrlén ◽  
Ayco J. M. Tack
Keyword(s):  
Powdery Mildew ◽  
Plant Pathogen ◽  
Quercus Robur ◽  
Time Dependent ◽  
Plant Performance ◽  
Pedunculate Oak ◽  
Insect Interactions ◽  
Species Specific ◽  
The Impact ◽  
Single Versus

Insects and pathogens frequently exploit the same host plant and can potentially impact each other's performance. However, studies on plant–pathogen–insect interactions have mainly focused on a fixed temporal setting or on a single interaction partner. In this study, we assessed the impact of time of attacker arrival on the outcome and symmetry of interactions between aphids ( Tuberculatus annulatus ), powdery mildew ( Erysiphe alphitoides ), and caterpillars ( Phalera bucephala ) feeding on pedunculate oak, Quercus robur , and explored how single versus multiple attackers affect oak performance. We used a multifactorial greenhouse experiment in which oak seedlings were infected with either zero, one, two, or three attackers, with the order of attacker arrival differing among treatments. The performances of all involved organisms were monitored throughout the experiment. Overall, attackers had a weak and inconsistent impact on plant performance. Interactions between attackers, when present, were asymmetric. For example, aphids performed worse, but powdery mildew performed better, when co-occurring. Order of arrival strongly affected the outcome of interactions, and early attackers modified the strength and direction of interactions between later-arriving attackers. Our study shows that interactions between plant attackers can be asymmetric, time-dependent, and species specific. This is likely to shape the ecology and evolution of plant–pathogen–insect interactions.

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