SOME EFFECTS OF ANOXIA AND HYPOXIA ON THE EUROPEAN RED MITE, PANONYCHUS ULMI (ACARINA: TETRANYCHIDAE)

1968 ◽  
Vol 100 (6) ◽  
pp. 617-623 ◽  
Author(s):  
Wm. L. Putman
Keyword(s):  
Relative Humidity ◽  
Panonychus Ulmi ◽  
High Humidity ◽  
Immature Stages ◽  
Pure Nitrogen ◽  
Adult Females ◽  
European Red Mite ◽  
Partial Paralysis

AbstractProgressively increasing lengths of exposure to pure nitrogen caused temporary anaesthesia, irreversible partial paralysis, and death, in that order, to the European red mite, Panonychus ulmi (Koch). The immature stages, especially eggs, were more tolerant than adult females. Confinement in 2.5% oxygen at a relative humidity approximating 100% had no effect on the mites, except on oviposition, beyond that of high humidity alone.

EFFECTS OF WATER AND HIGH HUMIDITY ON THE EUROPEAN RED MITE, PANONYCHUS ULMI (ACARINA: TETRANYCHIDAE)

1970 ◽  
Vol 102 (8) ◽  
pp. 955-961 ◽  
Author(s):  
Wm. L. Putman
Keyword(s):  
Relative Humidity ◽  
Leaf Surface ◽  
Panonychus Ulmi ◽  
High Humidity ◽  
European Red Mite

AbstractWater deposited on peach leaves as a constantly replenished film for 48 hr killed few European red mites, Panonychus ulmi (Koch), by drowning. Considerably more, especially of larvae, were lost by their coming loose from the water-covered leaf surface and floating off; the proportion thus lost did not differ greatly between 6- and 48-hr treatments. Relative humidity of 100% and to a lesser degree, 96–99%, inhibited activity and development.

EFFECTS OF HUMIDITY AND PHOSPHORUS ON POPULATIONS OF THE EUROPEAN RED MITE PANONYCHUS ULMI (ACARI: TETRANYCHIDAE)1

1989 ◽  
Vol 24 (3) ◽  
pp. 298-308
Author(s):  
Merle Dormond ◽  
Preston E. Hunter
Keyword(s):  
Relative Humidity ◽  
Host Plant ◽  
Laboratory Study ◽  
Panonychus Ulmi ◽  
Day Length ◽  
Combined Effects ◽  
Hoagland Solution ◽  
European Red Mite ◽  
Two Temperatures

A laboratory study investigating the combined effects of phosphorus and relative humidity upon reproduction by the European red mite Panonychus ulmi (Koch) was conducted. Phosphorus effects were tested at two levels (Hoagland solution with or without phosphorus) and relative humidity at five levels (6%, 30%, 60%, 75% and 90%). Experiments were run at two temperatures, 21°C and 25°C, and at a day-length regime of 16L:8D. The mites' response to phosphorus was characterized by a significant increase in progeny numbers when the host plant contained “high” levels of this element. Reaction to humidity was characterized by an increase in progeny at relative humidities between 60% and 75%. Under the same RH conditions, higher numbers of progeny were generally obtained from plants containing higher levels of phosphorus; the most favorable treatment was Hoagland solution with phosphorus and 75% RH.

FECUNDITY AND RATE OF DEVELOPMENT OF THE EUROPEAN RED MITE, PANONYCHUS ULMI (KOCH) (ACARINA: TETRANYCHIDAE), ON LEAVES FROM AN ABANDONED PEACH ORCHARD

1964 ◽  
Vol 42 (5) ◽  
pp. 719-722 ◽  
Author(s):  
Wm. L. Putman
Keyword(s):  
Population Density ◽  
Nutritional State ◽  
Panonychus Ulmi ◽  
Immature Stages ◽  
Rate Of Development ◽  
European Red Mite ◽  
Peach Orchard

The fecundity of the European red mite, Panonychus ulmi (Koch), reared on leaves from an abandoned peach orchard was equal to that of mites on leaves from a cultivated orchard, but the development of immature stages was slightly slower on leaves from the abandoned orchard. Poor nutritional state of the foliage is apparently not responsible for the very low population density of the mite in abandoned peach orchards.

scholarly journals Pathogenicity of Isaria fumosorosea to European red mite in the laboratory

Biotemas ◽  
2017 ◽  
Vol 30 (1) ◽  
pp. 73
Author(s):  
Cláudia Andréia Gräff ◽  
Liana Johann ◽  
Cláucia Fernanda Volken de Souza ◽  
Noeli Juarez Ferla
Keyword(s):  
Rio Grande ◽  
Panonychus Ulmi ◽  
Rio Grande Do Sul ◽  
Isaria Fumosorosea ◽  
European Red Mite

http://dx.doi.org/10.5007/2175-7925.2017v30n1p73A vitivinicultura no estado do Rio Grande do Sul tem sofrido infestações significativas de ácaros praga, destacando-se recentemente Panonychus ulmi (Koch). Há relatos sobre a capacidade de controle de ácaros fitófagos com Isaria fumosorosea. O objetivo deste trabalho foi avaliar em laboratório a ação patogênica de I. fumosorosea sobre o ácaro P. ulmi. As criações de P. ulmi foram estabelecidas a partir de coleta realizadas em videiras da Serra Gaúcha. Sobre os ovos de P. ulmi, as aplicações de suspensões de esporos foram feitas em diferentes concentrações. As triplicatas das fêmeas de 12 a 15 dias foram tratadas com suspensão a 108 esporos x mL-1. As testemunhas foram tratadas com água destilada. Após sete dias da aplicação, observaram-se 55,6% de ovos não eclodidos tratados com suspensão 106 esporos x mL-1 e com fêmeas tratadas obteve-se uma mortalidade total entre 85-90% e mortalidade confirmada entre 50-55%. A mortalidade máxima dos controles no tratamento dos ovos e das fêmeas foi, em média, de 12,8 e 15,5%, respectivamente. Conclui-se que o isolado I. fumosorosea possui habilidade para infectar ovos e fêmeas adultas de P. ulmi e portanto mostra-se como uma alternativa viável para ser experimentada no campo.

Polybutenes in Orchard Pest Control

1962 ◽  
Vol 94 (11) ◽  
pp. 1222-1227 ◽  
Author(s):  
R. S. Downing
Keyword(s):  
British Columbia ◽  
Pest Control ◽  
Spider Mite ◽  
Panonychus Ulmi ◽  
Phytophagous Mites ◽  
European Red Mite ◽  
Short Time ◽  
Methods Of Control

In British Columbia the control of phytophagous mites, especially the European red mite, Panonychus ulmi (Koch), and the McDaniel spider mite, Tetranychus mcdanieli McG., is becoming increasingly difficult, mainly because of the mites' ability to develop resistance to most acaricides in a relatively short time (3). Because of this, methods of control other than strictly chemical are examined at every opportunity.

scholarly journals Reproductive performance of spiralling whitefly on guava and impact of weather parameters on its immature stages

2018 ◽  
Vol 15 (2) ◽  
pp. 207-214
Author(s):  
I Hossain ◽  
MMH Khan ◽  
SMH Jahan
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Reproductive Performance ◽  
Significant Positive Correlation ◽  
Instar Nymph ◽  
Maximum Temperature ◽  
Immature Stages ◽  
Positive Correlation ◽  
Aleurodicus Dispersus ◽  
Weather Parameters

The study was conducted to know the reproductive performance of spiralling whitefly on guava. Number of colony, eggs, 1st instar, 2nd instar, 3rd instar and 4th instar nymphs per five leaves ranged from 6 to 15, 8 to 32, 0 to 44, 0 to 22, 0 to 45 and 0 to 28, respectively. Maximum number of adults and nymphs were found in the month of January. Highest longevity of Aleurodicus dispersus (21.5 days) was recorded in adult while the lowest was in 2nd instar nymph (6.4 days). The number of colony/leaf and number of 3rd and 4th instar nymphs of A. dispersus had significant positive correlation with minimum and maximum temperature while non-significant positive correlation is observed between the number of egg/colony, the number 1st and 2nd instar nymphs with minimum and maximum temperature. A. dispersus showed nonsignificant positive correlation with minimum and maximum relative humidity regarding number of colony/leaf, 2nd instar nymph while nonsignificant negative correlation with 4th instar nymph.SAARC J. Agri., 15(2): 207-214 (2017)

scholarly journals Reproductive diapause in Nysius huttoni White (Heteroptera Lygaeidae)

2002 ◽  
Vol 55 ◽  
pp. 308-311
Author(s):  
X.Z. He ◽  
Q. Wang ◽  
A. Carpenter
Keyword(s):  
Life Cycle ◽  
Immature Stages ◽  
Life Stages ◽  
Reproductive Diapause ◽  
Entire Life ◽  
Entire Life Cycle ◽  
Adult Females ◽  
Critical Photoperiod

The induction of reproductive diapause of Nysius huttoni was studied in the laboratory at 20 1C and 60 10 RH under a series of photoperiod regimes 168 h 1410 h 1212 h and 1014 h lightdark Reproductive diapause was considered to have occurred if females failed to lay eggs for 50 days after emergence The sensitivity of different life stages to diapauseinducing photoperiods varied When newly emerged females whose immature stages had been reared at 168 h were transferred to 1014 h and 1212 h 467 and 793 of them entered reproductive diapause respectively However when fifth instar nymphs were transferred from 168 h to 1014 h and 1212 h 100 of adult females entered reproductive diapause If the entire life cycle was maintained at 1014 h and 1212 h 667 and 400 of females entered reproductive diapause respectively The critical photoperiod for reproductive diapause was estimated to lie between 1311 h and 135105 h

STUDIES OF THE AGING OF CONIDIA OF MONILINIA FRUCTICOLA (WINT.) HONEY: I.GERMINATION RATES AND LONGEVITY

1957 ◽  
Vol 35 (5) ◽  
pp. 635-645 ◽  
Author(s):  
S. H. Z. Naqvi ◽  
H. M. Good
Keyword(s):  
Relative Humidity ◽  
Storage Temperature ◽  
Potato Dextrose Agar ◽  
Monilinia Fructicola ◽  
High Humidity ◽  
Percentage Germination ◽  
Low Humidity ◽  
Nutrient Solutions

Conidia of Monilinia fructicola (Wint.) Honey were stored 1–10 months at temperatures of 5°, 25°, and 35 °C. and at constant relative humidities approximating 0, 15, 45, 75, and 90%. The germination of these spores was tested on potato dextrose agar containing 6% glucose, and curves of the percentage germination against time are given for representative samples.A pronounced delay in germination developed under all conditions of storage. The rate at which this delay developed was virtually independent of the storage temperature. All spore samples gave 100% germination after 3 months but only those at 5 °C. gave; any germination after 10 months. Storage in a relative humidity of 75% gave the best preservation of spore vigor, there being evidence in other conditions of either high humidity or low humidity injury. Of the nutrient solutions tested, glucose was the only one which gave substantially better germination than water, the effect being most marked on spores stored for some months at high humidity. With glucose, such spores sometimes germinated faster than those stored at intermediate humidities.

Episodic basin-scale soil moisture anomalies associated with high relative humidity events in the McMurdo Dry Valleys, Antarctica

2021 ◽  
pp. 1-15
Author(s):  
Joseph Levy
Keyword(s):  
Soil Moisture ◽  
Relative Humidity ◽  
Mcmurdo Dry Valleys ◽  
Limiting Factor ◽  
High Humidity ◽  
Dry Valleys ◽  
Surface Soils ◽  
Basin Scale ◽  
Soil Reflectance

Abstract Outside of hydrologically wetted active layer soils and humidity-sensitive soil brines, low soil moisture is a limiting factor controlling biogeochemical processes in the McMurdo Dry Valleys. But anecdotal field observations suggest that episodic wetting and darkening of surface soils in the absence of snowmelt occurs during high humidity conditions. Here, I analyse long-term meteorological station data to determine whether soil-darkening episodes are present in the instrumental record and whether they are, in fact, correlated with relative humidity. A strong linear correlation is found between relative humidity and soil reflectance at the Lake Bonney long-term autonomous weather station. Soil reflectance is found to decrease annually by a median of 27.7% in response to high humidity conditions. This magnitude of darkening is consistent with soil moisture rising from typical background values of < 0.5 wt.% to 2–3 wt.%, suggesting that regional atmospheric processes may result in widespread soil moisture generation in otherwise dry surface soils. Temperature and relative humidity conditions under which darkening is observed occur for hundreds of hours per year, but are dominated by episodes occurring between midnight and 07h00 local time, suggesting that wetting events may be common, but are not widely observed during typical diel science operations.

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