THE RELATIVE ACTIVITY AND FUNCTIONAL RESPONSE OF PHYTOSEIULUS PERSIMILIS (ACARINA: PHYTOSEIIDAE) AND TETRANYCHUS URTICAE (ACARINA: TETRANYCHIDAE): THE EFFECT OF TEMPERATURE

1980 ◽  
Vol 112 (1) ◽  
pp. 17-24 ◽  
Author(s):  
P. Everson

AbstractThe activity of the predacious mite Phytoseiulus persimilis Athias-Henriot was greater oh a glass substrate than on a bean leaf substrate. Temperature did not affect its relative activity on the two substrates. The phytophagous mite Tetranychus urticae Koch was inactive on the bean leaf substrate. It was active on the glass substrate and its activity varied with temperature. The functional response of P. persimilis and T. urticae was examined at four temperatures (15°, 20°, 25°, 30 °C). Each functional response to increasing temperature rose curvilinearly to a plateau. From Holling’s disk equation, rate of successful search increased and handling time decreased.

1979 ◽  
Vol 111 (1) ◽  
pp. 7-10 ◽  
Author(s):  
P. Everson

AbstractThe functional response of the predacious mite Phytoseiulus persimilis Athias-Henriot to increases in the prey density of adult female Tetranychus urticae Koch was examined. Previous studies on artificial substrates have described the functional response curve of P. persimilis to adult female prey as dome-shaped, because as prey density increased the predator was disturbed by prey activity.An experiment to determine the effect of artificial and natural substrates on the activity level of T. urticae was conducted. T. urticae showed a significant increase in activity on artificial substrates of plastic and waterproof paper compared with a substrate of excised bean leaf (Phaseolus vulgaris L.). Since prey activity was significantly influenced by substrate, the functional response of P. persimilis to adult female T. urticae was re-examined. P. persimilis exposed to various densities of T. urticae on excised bean leaf disks (5 cm2) showed a functional response curve having a curvilinear rise to a plateau as prey densities increased from 0.2 to 10.0 prey/cm2.The functional response curve predicted by Holling’s disk equation did not differ significantly from the observed functional response curve.The rate of successful search and the handling time predicted by the disk equation were 0.194 and 10.34 h respectively.


Author(s):  
Azadeh Farazmand ◽  
Masood Amir-Maafi

Abstract In this research, functional responses of Amblyseius swirskii Athias-Henriot preying on different Tetranychus urticae Koch nymphal densities (2, 4, 8, 16, 32, 64, and 128) were studied at eight constant temperatures (15, 20, 25, 27.5, 30, 32.5, 35 and 37.5°C) in a circular Petri dish (3-cm diameter × 1-cm height) under lab conditions. At all temperatures, the logistic regression showed a type II functional response. A nonlinear relationship was found between temperature and attack rate and the reciprocal of handling time. The reciprocal of handling time decreased exponentially with increasing temperature. In contrast, the attack rate grew rapidly with increasing temperatures up to an optimum, showing a decreasing trend at higher temperatures. In order to quantify the functional response of A. swirskii over a broad range of temperatures and to gain a better estimation of attack rate and handling time, a temperature-settled functional response equation was suited to our data. Our model showed that the number of prey consumed increased with rising prey density. Also, the predation rates increased with increasing temperatures but decreased at extremely high temperatures. Based on our model, the predation rate begins at the lower temperature threshold (11.73°C) and reaches its peak at upper temperature threshold (29.43°C). The coefficient of determination (R2) of the random predator model was 0.99 for all temperatures. The capability of A. swirskii to search and consume T. urticae over a wide range of temperatures makes it a good agent for natural control of T. urticae in greenhouses.


2019 ◽  
Vol 79 (2) ◽  
pp. 273-277 ◽  
Author(s):  
J. I. Monjarás-Barrera ◽  
J. C. Chacón-Hernández ◽  
E. Cerna-Chávez ◽  
Y. M. Ochoa-Fuentes ◽  
L. A. Aguirre-Uribe ◽  
...  

Abstract The biological control used for the control of Tetranychus urticae (Koch) is the predator mite Phytoseiulus persimilis (Athias-Henriot). It is important to the know the effects of acaricides on the biological behavior the Abamectin on the functional response of P. persimilis. The functional response of the predator was of type II exposed to concentration of Abamectin, the functional response parameters: successful attack rate (a’), handling time (Th), search efficiency and the maximum predation theory (T/Th) were affected by the acaricide. The predator spends more time in persecute, dominate, consume and prepair it self to the next searching comparing with the proof subject an the predation ability was affected.


1970 ◽  
Vol 29 ◽  
pp. 1-8 ◽  
Author(s):  
Md Fazlul Hoque ◽  
Md Wahedul Islam ◽  
M Khalequzzaman

This paper examines the effect of density and temperature on the functional response of adult female Phytoseiulus persimilis to different life stages of the spider mite, Tetranychus urticae. The functional response was determined using functional response assay technique with plant leaf discs an arena. We conducted a logistic regression of the proportion of prey consumed as a function of initial prey density to identify functional response types, and used nonlinear least-squares regression and the random predator equation to estimate attack rates and handling times. In all the cases number of adult male prey attacked by female predator were greater than adult female prey. P. persimilis consumed more eggs and larvae than other stages of prey. Female predator consumed adult prey at each temperature which generally increased with prey density initially but leveled off at higher prey densities. The highest number of eggs, larvae and nymphs consumed by predator in 24 hours was 16.3 ± 0.42, 9.9 ± 0.59 and 9.5 ± 0.40 respectively whereas the highest number of eggs, larvae and nymphs consumed by a single female in 48 hours was 19.5 ± 1.15, 18.6 ± 0.62 and 13.3 ± 0.65 respectively. Handling time generally decreased with temperature whereas successful attack rate increased with temperature except at 30º C. Judging by a/Th values, P. persimilis was most efficient against T. urticae at 30-35ºC, about half as efficient at 25 ºC and performed poorly at 20º C. Again, from a/Th values, P. persimilis was most efficient against T. urticae in egg stage, about half as efficient at larva and nymph stages and performed poorly at adult stage.   Key words: Phytoseiulus persimilis; Tetranychus urticae; functional response; predation; temperature.DOI: http://dx.doi.org/10.3329/ujzru.v29i1.9458 UJZRU 2010; 29(1): 1-8


2017 ◽  
Vol 66 (2) ◽  
Author(s):  
Víctor Ernesto Tello Mercado ◽  
Miguel Esteban Zarzar Maza ◽  
Angélica María Suarez Pantoja

The functional response of adult females of predatory mite Cydnodromus picanus Ragusa (Acari: Phytoseiidae) was evaluated at different egg densities (5, 10, 20, 30, 40, 50, 60, 70, 80, 100 and 150 eggs per predator) of Tetranychus urticae Koch (Acari: Tetranychidae), which had 16, 42 and 65 h since oviposition. The experimental design was in a completely randomized blocks with five replicates per treatment. The environmental conditions of the trials were 25±2°C temperature, 50±2% of relative humidity and a photoperiod of 16:8 hours (light: dark). The average consumption rates for the three kinds of prey showed no significant differences (p>0.05) being 20.56±1.02, 18.59±0.79 and 18.38±0.94 prey/predator for eggs of 16, 42 and 65 h age, respectively. Using a logistic regression, a type II functional response on C. picanus females for the three kinds of eggs was determined. The values of response parameters for C. picanus females were as follows: Attack rate (a): 0.055±0.006, 0.076±0.009 and 0.073±0.016; Handling time (Th): 0.684±0.036, 0.894±0.034 and 0.898±0.062; for eggs of 16, 42 and 65 h age, respectively. These values are within the range of variation for different species of phytoseiids. These results suggest that C. picanus could effectively regulate populations of T. urticae in the field.  


2019 ◽  
Vol 54 (3) ◽  
pp. 275 ◽  
Author(s):  
Julio C. Chacón-Hernández ◽  
Ernesto Cerna-Chávez ◽  
Venancio Vanoye-Eligio ◽  
Yisa M. Ocho-Fuentes ◽  
Salvador Ordaz-Silva ◽  
...  

1981 ◽  
Vol 113 (4) ◽  
pp. 333-336 ◽  
Author(s):  
P. R. Everson ◽  
N. V. Tonks

AbstractThe relationship between posttreatment temperatures of 15°, 20°, 25°, and 30°C and toxicity of six pesticides to adult female Phytoseiulus persimilis Athias-Henriot and Tetranychus urticae Koch were studied in the laboratory.The toxicities of cyhexatin, dicofol, propargite, citrazon, chlorobenzilate, and per-methrin were positively correlated with temperature. Except for propargite and permefhrin, P. persimilis was less susceptible than T. urticae at 15° and 20°C, but equal in susceptibility at 25° and 30°C.The results obtained may indicate a potential value of posttreatment temperature manipulation as a useful adjunct to integrated pest control programs in glasshouses.


1966 ◽  
Vol 44 (3) ◽  
pp. 483-491 ◽  
Author(s):  
Hans Mori ◽  
D. A. Chant

The functional response of the predacious mite Phytoseiulus persimilis Athias-Henriot was tested at various densities of Tetranychus urticae (Koch), a prey species, and at several levels of humidity and hunger. The consumption of adult prey per predator rose at first with increasing prey density, but significantly decreased at high densities. This phenomenon was caused by an increase in abandonment of captures resulting from disturbance by other prey at high prey densities. Egg consumption by the predator increased with prey density.Prey consumption was greater at low than at high humidities. A significant increase in the rate of repeat feeding was found at higher levels of predator hunger, but the differences in consumption of prey between the three levels of hunger were not significant.


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