Effect of biotic and abiotic factors on the morphometric variability of Paratrichodorus rhodesiensis (Nematoda: Trichodoridae) from Senegal

Nematology ◽  
2003 ◽  
Vol 5 (3) ◽  
pp. 463-477
Author(s):  
Mandefro Wondirad ◽  
Wilfrida Decraemer ◽  
Pierre Baujard
Keyword(s):  
Body Length ◽  
Interaction Effect ◽  
Abiotic Factors ◽  
Tail Length ◽  
Effect Of Temperature ◽  
Morphometric Characters ◽  
Biotic And Abiotic Factors ◽  
Temperature And Humidity ◽  
Controlled Environments ◽  
Effects Of Temperature

AbstractEffects of temperature, humidity, temperature and humidity interaction and host on morphometric variability of Paratrichodorus rhodesiensis were studied. Nematode cultures were established in a glasshouse under controlled environments. Amongst the factors investigated, host was found to be the most influential on both sexes (P < 0.05) affecting all characters in females and eight out of 11 characters in males. Ratios b and c were found to be highly variable and hence their use is not suggested. On the contrary, ratio a was found to be a good indicator of nematode condition, particularly in association with hosts. Vulva position (V) was found to be the most stable character. Paratrichodorus rhodesiensis was affected by higher temperatures of 34 and 36°C. Change in humidity did not show a demonstrable trend on morphometric characters in both sexes. Interaction effect of temperature and humidity resulted in a significant effect on body length and body diameter in females and on ratio b and c, pharynx, onchiostyle and tail length in males.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

The Influence of Temperature and Humidity on Instar Length in Calandra Granaria Linn

1947 ◽  
Vol 24 (1-2) ◽  
pp. 79-94
Author(s):  
L. E. S. EASTHAM ◽  
F. SEGROVE
Keyword(s):  
Growth And Development ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Food Utilization ◽  
Optimum Temperature ◽  
Atmospheric Humidity ◽  
Larval Instars ◽  
Balance Sheets ◽  
Temperature And Humidity ◽  
Effects Of Temperature

1. The effects of temperature and humidity on the duration of each instar of the life cycle of Calandra granaria Linn. have been examined. The insects were reared at temperatures ranging from 15 to 30° C. and at atmospheric humidities ranging from 40 to 80% R.H. 2. A method is described for assessing the effect of temperature as an independent factor. 3. The temperatures employed fall within the ‘vital zone’. Extrapolation indicates the threshold temperature to be approximately 11° C. for the egg and larval instars though somewhat lower for the pupa. 30° C. is below the optimum temperature. 4. The durations of the egg and pupal stages are not affected by atmospheric humidity. 5. The duration of all larval instars is affected by moisture. It is suggested that this is largely due to atmospheric humidity and that food water is of little significance. 6. Shortage of moisture acts as an obstacle to development. Evidence is presented which indicates that drier atmospheres tend to desiccate the insect and that desiccation is responsible for retarded growth and development. 7. Since much earlier work on temperature and moisture has been done on fasting insects and, therefore, on insects deficient in one of the most important environmental factors, we suggest that our results, incomplete as they are, indicate the need for new approaches to be made. More complete data on feeding insects under controlled conditions of food, temperature and moisture are required, from which can be drawn up more complete balance sheets of development involving measurements of food utilization and respiratory rates.

Effects of Temperature and Humidity on the Rust-Red Flour Beetle, Tribolium-Castaneum (Herbst) (Coleoptera, Tenebrionidae), in Wheat-Grain

1987 ◽  
Vol 35 (1) ◽  
pp. 43 ◽  
Author(s):  
GG White
Keyword(s):  
Tribolium Castaneum ◽  
Larval Survival ◽  
Population Increase ◽  
Effect Of Temperature ◽  
Wheat Grain ◽  
Mathematical Functions ◽  
Temperature And Humidity ◽  
Survival And Development ◽  
Effects Of Temperature ◽  
Coleoptera Tenebrionidae

Rates of survival and development of the immature stages of Tribolium castaneum (Herbst) (Coleoptera : Tenebrionidae) were determined in wheat grain at constant temperatures from 20 to 37.5�C and constant relative humidities from 25 to 65%. The rates for eggs and pupae were similar to those previously published for T. castaneum in flour, but larval development was slower and mortality greater, except at low temperature and high humidity. The effect of temperature and humidity on rates of fertility and oviposition in young adults were also determined in wheat grain. The patterns of effects of temperature and humidity on oviposition were similar to those previously published for T. castaneum in flour, but the maximum observed oviposition rate was lower. Fertility was significantly reduced when densities of adults were greater than one pair per 250 g. Mathematical functions were fitted to data from the present and previous studies on age-specific survival and fecundity of adults; population growth rate statistics were calculated from life-table parameters defined by these functions. Under optimal conditions within the range of the present study (35�C, 65% RH), the innate capacity for increase rm was 0.84 per week. The limits for population increase, where rm is zero, were largely determined by.the limits for larval survival, which were approximately 35% RH, and 20-22�C at the lower limit and 40�C at the upper limit.

Exogenous factors of nuclear DNA fragmentation in bulls sperm

2021 ◽  
Vol 1 (1) ◽  
pp. 59-64
Author(s):  
B. S. Iolchiev ◽  
◽  
P. M. Klenovitsky ◽  
P. N. Abramov ◽  
A. V. Tadzhieva ◽  
...  
Keyword(s):  
Geomagnetic Activity ◽  
Nuclear Dna ◽  
Abiotic Factors ◽  
Dispersion Analysis ◽  
Effect Of Temperature ◽  
Important Indicator ◽  
Biotic And Abiotic Factors ◽  
K Index ◽  
Exogenous Factors ◽  
Nuclear Dna Fragmentation

Herd reproduction is the most important indicator of the economic efficiency of the industry. Assisted reproductive technology, especially artificial insemination, is widely used in dairy farming. When using this method, tens of thousands of cows and heifers are inseminated with the seed of a single bull, therefore, the used biomaterial must meet high requirements, since the use of low-quality sperm products can lead to multi-million losses. The reproductive performance of breeding bulls depends on numerous biotic and abiotic factors. breeding bulls depends on numerous biotic and abiotic factors. The purpose of the study the influence of meteorological factors on the biological usefulness of sperm from bulls of different breeds. A multidimensional dispersion analysis of the effect of temperature and geomagnetic activity on the quality of spermatozoa was performed. The results of multidimensional dispersion analysis show that the combination of temperature factors with geomagnetic activity has a statistically significant effect on the content of spermatozoa with abnormal movement in the fresh seed and on the activity of spermatozoa (p<0,05). Geomagnetic activity (K-index ≥5,0) leads to an increase in the proportion of spermatozoa with pathological morphology. This trend was observed regardless of the season of the year. During the summer period, on days with increased geomagnetic activity, the content of spermatozoa with pathology increased by 66% compared to the period when there is no magnetic disturbance. Under the influence of geomagnetic activity, the proportion of spermatozoa with abnormal movement increased – such spermatozoa in the ejaculate contained an average of 10,2%, depending on the season and temperature, this indicator varied from 6 to 21,5%. High geomagnetic activity and temperature lead to an increase in the proportion of spermatozoa with a violation of the structure of nDNA.

scholarly journals First report of the nematodes Filenchus orientalis and Hemicriconemoides californianus on faba bean in Iran

2016 ◽  
Vol 9 (1) ◽  
pp. 44-50
Author(s):  
S. Azimi ◽  
E. Mahdikhani-Moghadam ◽  
H. Rouhani ◽  
H. Rajabi Memari
Keyword(s):  
Body Length ◽  
Tail Length ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Morphometric Characters ◽  
Lateral Field ◽  
Stylet Length ◽  
First Time ◽  
Plant Parasitic ◽  
Iranian Populations

Summary During a survey in Iran, two known species of plant-parasitic nematodes of the families Tylenchidae and Criconematidae were reported for the first time. The morphological and morphometric characters of Iranian populations of the two recovered species are discussed and illustrated based on morphological and morphometrics data. Iranian population of Filenchus orientalis is characterized by having a 601-755μm body length, stylet length of 9.0-11.3 μm, lateral field with four incisures, tail length of 100-118 μm and males with 15-21 μm long spicules. Hemicriconemoides californianus population is characterized by having a body length of 430-550μm, lip region with two annuli, stylet length of 75-83μm and tail length of 20-28 μm. The morphological and morphometric characters of both species are in agreement with those in original descriptions.

scholarly journals The Effects of Temperature and Humidity on the Cheese Skipper, Piophila Casei (L.)

1935 ◽  
Vol 12 (4) ◽  
pp. 384-388
Author(s):  
JOHN SMART
Keyword(s):  
High Temperatures ◽  
Effect Of Temperature ◽  
Secondary Effect ◽  
Short Series ◽  
Thermal Death ◽  
Temperature And Humidity ◽  
Series Of Experiments ◽  
Thermal Death Point ◽  
Effects Of Temperature ◽  
Lower Temperature

The paper gives the results of a short series of experiments carried out to determine the thermal death-point under conditions of controlled humidity of the larva and pupa of the Cheese Skipper, Piophila casei (L.). The larva is remarkable for the high temperatures it can withstand, namely 52° C., for 1 hour's exposure and 45° C. for an exposure of 24 hours. The death of the pupa at a much lower temperature is shown to be due to a secondary effect of temperature on its physiology.

Effect of Temperature and Humidity on Measuring Ionization Current Inside Contaminated Pipes

2013 ◽  
Author(s):  
Pingchuan Li ◽  
Xianguo Tuo ◽  
Mingzhe Liu ◽  
Jun Ren ◽  
Qibiao Wang ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Long Range ◽  
Regression Method ◽  
Experimental Results ◽  
Ion Current ◽  
Effect Of Temperature ◽  
Multiple Regression Method ◽  
Temperature And Humidity ◽  
Different Temperatures ◽  
Effects Of Temperature

This paper reported the experimental results of ion current under different temperatures and relative humidity using long range alpha detector (LRAD). An approximation relation between the measuring values, temperatures and relative humidity has been obtained using the linear multiple regression method. The experimental results have shown that the measuring values decrease with the increase of temperature and humidity. The influence of humidity on results outweighs that of temperatures. And both temperature and humidity are obviously negative correlated with measured values. Further experiments will be performed to confirm the coupling effects of temperature and humidity and reported later.

Effect of temperature, population density, and sex on feeding damage caused by adult pea leaf weevil (Coleoptera: Curculionidae)

2020 ◽  
pp. 1-10
Author(s):  
Vivian Morley-Senkler ◽  
Jonathon Williams ◽  
Meghan Vankosky
Keyword(s):  
Population Density ◽  
Feeding Rate ◽  
Abiotic Factors ◽  
Daily Temperature ◽  
Effect Of Temperature ◽  
Feeding Damage ◽  
Growing Seasons ◽  
Temperature Regimes ◽  
Important Pest ◽  
Effects Of Temperature

Abstract Sitona lineatus (Linnaeus) (Coleoptera: Curculionidae) is an important pest of Pisum sativum Linnaeus (Fabaceae) and Vicia faba Linnaeus (Fabaceae). Managing S. lineatus is difficult. There is currently no forecast that can be used to predict S. lineatus population densities between growing seasons (when management decisions are made). Sitona lineatus populations are monitored in spring by assessing adult-induced feeding damage. We assume the quantity of feeding damage is indicative of population density. However, the effects of abiotic factors, including temperature, on feeding rate are not known. We assessed the effects of temperature, population density, and sex on S. lineatus feeding rate by counting feeding notches on host plants exposed to adult weevils for 24 hours at four densities and under five temperature regimes. Individual females consumed more than male weevils. As expected, feeding damage increased with weevil density. The influence of temperature increased as weevil densities increased. Feeding rate did not differ between constant and fluctuating temperature regimes of equal mean daily temperature. Thus, a model based on mean daily temperature may predict weevil density if temperature and damage levels are known. Historical survey data for S. lineatus could be used to develop and validate new models.

scholarly journals Effects of temperature on decomposition of a potential nuisance species: the submerged aquatic macrophyte Egeria najas planchom (Hydrocharitaceae)

2005 ◽  
Vol 65 (1) ◽  
pp. 51-60 ◽  
Author(s):  
P Carvalho ◽  
S. M. Thomaz ◽  
L. M. Bini
Keyword(s):  
Aquatic Macrophyte ◽  
Abiotic Factors ◽  
Analysis Of Covariance ◽  
Effect Of Temperature ◽  
Phosphorus Concentration ◽  
Total Phosphorus Concentration ◽  
Significant Difference ◽  
Nuisance Species ◽  
Effects Of Temperature ◽  
Egeria Najas

Decomposition of aquatic plants is influenced by several biotic and abiotic factors. Among them, temperature plays an important role. Despite the increasing number of studies describing the effects of temperature on the decomposition of aquatic macrophytes, little attention has been given to the decay of submerged macrophytes. In this paper, we assessed the effect of temperature on weight loss and chemical composition of detritus of the submerged aquatic macrophyte Egeria najas Planchon (Hydrocharitaceae). Fresh plant material was maintained at 17ºC and 27ºC, in the dark, in incubation chambers. The overall decay process was best described by a linear model, with rates of 0.014 day-1 (R² = 94%) and 0.045 day-1 (R² = 96%) obtained at 17ºC and 27ºC, respectively. The analysis of covariance (ANCOVA) indicated a significant difference between the decomposition rates at the two temperatures. The rapid breakdown of E. najas detritus, indicated by the decay coefficient, may be explained by its low content of resistant compounds such as cellulose and lignin. The variables analyzed in this study (pH, electrical conductivity, dissolved oxygen in the water and organic matter, total nitrogen and total phosphorus concentration in detritus) showed accentuated responses at 27ºC. It is likely that the higher temperature increased microbial activity and, therefore, oxygen consumption in the water, consequently affecting the pH and the rate of ion and nutrient liberation into the aquatic ecosystem. Due to the rapid decomposition of E. najas at high temperatures, a small exportation is expected of this species from its stands to distant regions in tropical reservoirs, where it is considered a potential nuisance species.

The effect of temperature and photoperiod on primary floral induction in three lines of alpine bluegrass

1997 ◽  
Vol 77 (4) ◽  
pp. 615-622 ◽  
Author(s):  
Michelle Pahl ◽  
Barb Darroch
Keyword(s):  
Floral Induction ◽  
Effect Of Temperature ◽  
Short Day ◽  
Long Day ◽  
Marked Inhibition ◽  
Controlled Environments ◽  
Primary Induction ◽  
Effects Of Temperature ◽  
Short Days ◽  
Induction Temperature

The effects of temperature and photoperiod on primary floral induction in three lines of alpine bluegrass (Poa alpina L.) were studied in controlled environments. These lines were developed at the Alberta Environmental Centre from single plant accessions collected from the Alberta Rocky Mountains. Plants representing all three lines were subjected to temperatures of 3, 9, and 12 °C under dark (0 h), short-day (8 h), and long-day (18 h) photoperiods for durations of 6, 10, and 14 wk. Plants were subsequently transferred to conditions of 22 °C/15 °C, 18 h photoperiod and heading response was recorded. Primary floral induction was found to be favoured by low temperatures and/or short days with marked inhibition at 12 °C. Complete dark conditions were not inductive. Six weeks of primary induction was suboptimal with only 15% of plants flowering. However, 100% of plants flowered after 10 wk of primary induction at 3 °C under both long-day and short-day conditions. Differences among lines were significant for number of heading plants, number of heads per plant, time to heading, and critical induction duration. Primary induction in line 907 occurred at longer photoperiods, warmer temperatures, and in shorter durations than the other lines indicating a lesser induction requirement. Possible implications are discussed in the use of alpine bluegrass populations for revegetating disturbed mountain sites. Key words: Floral induction, temperature, photoperiod, Poa alpina, alpine bluegrass

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