Abiotic effects on the clear-winged grasshopper (Orthoptera: Acridae) and its fungal pathogen Entomophaga grylli (Entomophthorales: Entomophthoraceae) in an intermountain bunch-grass prairie

2017 ◽  
Vol 149 (3) ◽  
pp. 315-325
Author(s):  
Erica J. Kistner ◽  
Gary E. Belovsky

AbstractThe grasshopper, Camnula pellucida Scudder (Orthoptera: Acridae), is a severe pest of small grains and rangeland forage in North America. In a field experiment using cages containing C. pellucida in northwestern Montana, United States of America, we manipulated exposure to the fungal entomopathogen, Entomophaga grylli Fresenius (Entomophthorales: Entomophthoraceae) pathotype 1, temperature using small greenhouses, and moisture for the pathogen with water pillows. Treatment effects on fungal infection (mycosis) rates and grasshopper survivorship were assessed. Water pillows provided additional moist habitat for E. grylli without having an impact on grasshopper performance or the plant biomass and nitrogen content. Number of fungal spores, pathogen-induced mortality rates, and treatment effects on grass biomass and nitrogen content were also measured. Water pillows benefited the pathogen by increasing fungal spore levels by eightfold, which in turn shortened pathogen-exposed grasshopper survival time by half. In contrast, warming reduced fungal spore levels by 50% and subsequently reduced mortality from E. grylli by 67%. However, warmed pathogen-exposed grasshoppers did not exhibit enhanced survival, which may be due, in part, to intraspecific competition among the surviving grasshoppers.

Author(s):  
Raghdaa K. Fayad ◽  
Roda F. Al-Thani ◽  
Fatima A. Al-Naemi ◽  
Mohammed H. Abu-Dieyeh

This research was conducted to investigate the dynamics of airborne fungi using viable culture collection and in respect to different abiotic variables, including seasonal and intra-diurnal variations. A gravimetric method was used to sample airborne fungal deposition on potato dextrose agar plates on alternate days, for a year between April 2015 to March 2016. From 176 settle plate exposures, a total of 1197 mould and 283 yeast colony-forming units (CFU), 21 genera and 62 species were retrieved. The highest fungal spore count was recorded in February 2016, whereas the lowest count occurred in August 2015. The main constituents of the fungal airspora were attributed to Cladosporium (60.2%), Aspergillus (10.4%), Fusarium (9.4%), Alternaria (8.5%), and Ganoderma spp. (2.3%). Temperature was negatively correlated with total colony count (r = −0.231, p ≤ 0.05) or species richness (r = −0.267, p ≤ 0.001), while wind speed was positively correlated with total colony count (r = 0.484, p ≤ 0.001) or species richness (r = 0.257, p ≤ −0.001). The highest dispersal of fungal spores was obtained at 18:00, whereas the lowest fungal spores release was recorded at 00:00 (midnight). There were no significant differences in species composition and richness of the airborne fungal population between two study sites, the Industrial area and Qatar University Campus. The count of Alternaria spp. and Fusarium spp. were significantly higher at the Industrial area site, which corresponds to a higher CO2 level than the Qatar University site. This study lays the foundation for future work to assess the implications of such aeromycological data on public health.


2018 ◽  
Author(s):  
Elizabeth Forde ◽  
Martin Gallagher ◽  
Virginia Foot ◽  
Roland Sarda-Esteve ◽  
Ian Crawford ◽  
...  

Abstract. Primary biological aerosol particles (PBAP) are an abundant subset of atmospheric aerosol particles which comprise viruses, bacteria, fungal spores, pollen, and fragments such as plant and animal debris. The abundance and diversity of these particles remain poorly constrained, causing significant uncertainties for modelling scenarios and for understanding the potential implications of these particles in different environments. PBAP concentrations were studied at four different sites in the United Kingdom (Weybourne, Davidstow, Capel Dewi, and Chilbolton) using an ultra-violet light induced fluorescence (UV-LIF) instrument, the Wideband Integrated Bioaerosol Spectrometer (WIBS), versions 3 and 4. Using hierarchical agglomerative cluster (HAC) analysis, particles were statistically discriminated between. Fluorescent particles and clusters were then analysed by assessing their diurnal variation and their relationship to the meteorological variables, temperature and relative humidity, and wind speed and direction. Using local land cover types, sources of the suspected fluorescent particles and clusters were then identified. Most sites exhibited a wet discharged fungal spore dominance, with the exception of one site, Davidstow, which had higher concentrations of bacteria, suggested to result from the presence of a local dairy factory. Differences were identified as to the sources of wet discharged fungal spores, with particles originating from arable and horticultural land at Chilbolton, and improved grassland areas at Weybourne. Total fluorescent particles at Capel Dewi were inferred to comprise two sources, with bacteria originating from the broadleaf and coniferous woodland and wet discharged fungal spores from nearby improved grassland areas, similar to Weybourne. The use of HAC and a higher fluorescence threshold (9SD) produced clusters which were considered to be biological following the complete analysis. More knowledge of the reaction of speciated biological particles to differences in meteorology, such as relative humidity and temperature would aid characterisation studies such as this.


1974 ◽  
Vol 52 (5) ◽  
pp. 953-958 ◽  
Author(s):  
William C. Elsik ◽  
Jan Jansonius

Ctenosporites, Granatisporites, and Pesavis are described as new form genera of fossil fungal spores and spore-like fossils; Striadiporites and Pluricellaesporites are emended. Pesavis and Ctenosporites are geographically restricted to the northwest Pacific and Arctic region. Granatisporites is described to facilitate the classification of fungal spore types ubiquitous over at least the Western Hemisphere.


1994 ◽  
Vol 68 (3) ◽  
pp. 664-668 ◽  
Author(s):  
Alfred Traverse ◽  
Sidney R. Ash

Palynoflorules containing sparse but regularly occurring chitinous-walled fungal, probably ascomycete, spores have been obtained from silty limestone nodules in the Jurassic Coon Hollow Formation in the Wallowa terrane in Hells Canyon, Idaho. The fungal spores are associated with moderately abundant embryophytic spores and pollen that suggest late Early Jurassic to early Middle Jurassic age, which agrees with dating provided by marine animals stratigraphically just above. The fungal spores constitute the most diverse such assemblage of robust-walled spores described from pre-Cretaceous rocks. Two new species of the fossil fungal spore form-genus Diporicellaesporites, D. idahoensis and D. serratulus, and one new species of form-genus Fractisporonites, F. pittsburgensis, are described.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Kazuyuki Kita ◽  
Yasuhito Igarashi ◽  
Takeshi Kinase ◽  
Naho Hayashi ◽  
Masahide Ishizuka ◽  
...  

Abstract It is the conventional understanding that rain removes aerosols from the atmosphere. However, the question of whether rain plays a role in releasing aerosols to the atmosphere has recently been posed by several researchers. In the present study, we show additional evidence for rain-induced aerosol emissions in a forest environment: the occurrence of radiocaesium-bearing aerosols in a Japanese forest due to rain. We carried out general radioactive aerosol observations in a typical mountainous village area within the exclusion zone in Fukushima Prefecture to determine the impacts and major drivers of the resuspension of radiocaesium originating from the nuclear accident in March 2011. We also conducted sampling according to the weather (with and without rain conditions) in a forest to clarify the sources of atmospheric radiocaesium in the polluted forest. We found that rain induces an increase in radiocaesium in the air in forests. With further investigations, we confirmed that the fungal spore sources of resuspended radiocaesium seemed to differ between rainy weather and nonrainy weather. Larger fungal particles (possibly macroconidia) are emitted during rainy conditions than during nonrainy weather, suggesting that splash generation by rain droplets is the major mechanism of the suspension of radiocaesium-bearing mould-like fungi. The present findings indicate that radiocaesium could be used as a tracer in such research fields as forest ecology, meteorology, climatology, public health and agriculture, in which fungal spores have significance.


The Holocene ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 218-232 ◽  
Author(s):  
Eline N van Asperen ◽  
Jason R Kirby ◽  
Helen E Shaw

The management of the remainder of Europe’s once extensive forests is hampered by a poor understanding of the character of the vegetation and drivers of change before the onset of clearance for farming. Pollen data indicate a closed-canopy, mixed-deciduous forest, contrasting with the assertion that large herbivores would have maintained a mosaic of open grassland, regenerating scrub and forested groves. Coprophilous fungal spores from sedimentary sequences are increasingly used as a proxy for past herbivore impact on vegetation, but the method faces methodological and taphonomical issues. Using pollen trap data from a long-running experiment in Chillingham Wild Cattle Park, UK, we investigate the first steps in the mechanisms connecting herbivore density to the incorporation of fungal spores in sediments and assess the effects of environmental variables on this relationship. Herbivore utilisation levels correlate with dung fungal spore abundance. Chillingham is densely populated by large herbivores, but dung fungal spore influx is low. Herbivores may thus be present on the landscape but go undetected. The absence of dung fungal spores is therefore less informative than their presence. Dung fungal spores likely enter the sediment record through a different pathway from wind-borne pollen and thus dung fungal abundance is better expressed as influx rates than as percentage of total pollen. Landscape openness, vegetation type and site wetness do not distort the impact of utilisation levels on dung fungal spore representation. However, dung fungal spore influx varies markedly between seasons and years. Spores travel, leading to a background level of spore deposition across the landscape, and at times a depletion of spores, especially under wet weather conditions. Animal behaviour, as well as husbandry practices, can lead to the accumulation of dung, and thus fungal spores, in specific locations on the landscape that do not directly reflect grazing pressure.


2006 ◽  
Vol 54 (4) ◽  
pp. 469-485 ◽  
Author(s):  
G. Singh ◽  
D. Wright

Effects of one pre-emergence herbicide (terbutryn/terbuthylazine) and one post-emergence herbicide (bentazone) along with unweeded and hand-weeded controls on weeds and on the nodulation, nitrogenase activity, nitrogen content, growth and yield of pea (Pisum sativum) were studied. Terbutryn/terbuthylazine was applied pre-emergence @ 1.40, 2.80 and 5.60 kg/hawhereas bentazone was sprayed 6 weeks after sowing @ 1.44, 2.88 and 5.76 kg/h. Terbutryn/terbuthylazine controlled all the weeds very effectively, whereas bentazone did not control some weeds such as Polygonum aviculare, Poa annua and Elymus repens. The herbicides decreased the number of nodules, the dry weight of nodules, the nitrogenase activity, the shoot dry weight, the nitrogen content in the straw and seeds, and the seed yield of peas, the effects generally being higher at higher rates of application. The adverse effects of herbicides on these parameters might be due to their effects on plant growth, as both the herbicides are known to adversely affect photosynthesis. Nitrogenase activity did not correlate well with plant-N content or shoot dry weight. However, there was a strong relationship between plant biomass and plant-N content, which suggests that researchers can rely on these parameters for studying the effects of treatments on nitrogen fixation, rather than measuring nitrogenase activity.


2016 ◽  
Vol 8 (5) ◽  
pp. 603-615 ◽  
Author(s):  
Layla J. Barkal ◽  
Naomi M. Walsh ◽  
Michael R. Botts ◽  
David J. Beebe ◽  
Christina M. Hull

Germination of a population of pathogenic fungal spores into yeast can be tracked, quantified, and parsed using a microfluidic assay.


2015 ◽  
Vol 15 (11) ◽  
pp. 6127-6146 ◽  
Author(s):  
M. Hummel ◽  
C. Hoose ◽  
M. Gallagher ◽  
D. A. Healy ◽  
J. A. Huffman ◽  
...  

Abstract. Fungal spores as a prominent type of primary biological aerosol particles (PBAP) have been incorporated into the COSMO-ART (Consortium for Small-scale Modelling-Aerosols and Reactive Trace gases) regional atmospheric model. Two literature-based emission rates for fungal spores derived from fungal spore colony counts and chemical tracer measurements were used as a parameterization baseline for this study. A third, new emission parameterization for fluorescent biological aerosol particles (FBAP) was adapted to field measurements from four locations across Europe. FBAP concentrations can be regarded as a lower estimate of total PBAP concentrations. Size distributions of FBAP often show a distinct mode at approx. 3 μm, corresponding to a diameter range characteristic for many fungal spores. Previous studies for several locations have suggested that FBAP are in many cases dominated by fungal spores. Thus, we suggest that simulated FBAP and fungal spore concentrations obtained from the three different emission parameterizations can be compared to FBAP measurements. The comparison reveals that simulated fungal spore concentrations based on literature emission parameterizations are lower than measured FBAP concentrations. In agreement with the measurements, the model results show a diurnal cycle in simulated fungal spore concentrations, which may develop partially as a consequence of a varying boundary layer height between day and night. Temperature and specific humidity, together with leaf area index (LAI), were chosen to drive the new emission parameterization which is fitted to the FBAP observations. The new parameterization results in similar root mean square errors (RMSEs) and correlation coefficients compared to the FBAP observations as the previously existing fungal spore emission parameterizations, with some improvements in the bias. Using the new emission parameterization on a model domain covering western Europe, FBAP in the lowest model layer comprise a fraction of 15% of the total aerosol mass over land and reach average number concentrations of 26 L−1. The results confirm that fungal spores and biological particles may account for a major fraction of supermicron aerosol particle number and mass concentration over vegetated continental regions and should thus be explicitly considered in air quality and climate studies.


2019 ◽  
Vol 93 ◽  
pp. 172-186 ◽  
Author(s):  
Lawrence M. Kiage ◽  
Meghan Howey ◽  
Joel Hartter ◽  
Michael Palace

AbstractNon-pollen palynomorphs and elemental geochemistry data from Lake Kifuruka in western Uganda provide evidence of environmental change in the tropical African region since the beginning of the Holocene. The multi-proxy record presented here shows that dry conditions dominated the end of the Pleistocene evidenced by calcium enriched sediments and suppressed fungal taxa activity. Moist conditions dominated the early Holocene and persisted until just after 1960 cal yr BP. Elevated frequencies of individual fungal spore taxa associated with herbivory and soil erosion, including Sordaria-type, Sporormiella-type, Chaetomium-type, and Glomus-type, about 4300 cal yr BP suggests a significant environmental change that could be linked to human activities. A convergence of multiple proxy data, including microscopic charcoal, elemental geochemistry, and fungal spores, strongly support the occurrence of anthropogenic forest disturbance in the Albertine Rift about 4300 cal yr BP.


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