ESTIMATING MITE POPULATIONS IN SOUTHERN OREGON PEAR ORCHARDS

1971 ◽  
Vol 103 (1) ◽  
pp. 67-71 ◽  
Author(s):  
P. H. Westigard ◽  
L. D. Calvin

AbstractStudies were conducted in southern Oregon pear orchards to develop sampling methods for assessment of mite abundance. Those species included in the investigation were the two-spotted spider mite, Tetranychus urticae Koch; European red mite, Panonychus ulmi (Koch); yellow spider mite, Eotetranychus carpini borealis (Ewing); and the predaceous phytoseiid Typhlodromus occidentalis Nesbitt.The results show that five leaves on one limb per tree are adequate to include representative numbers of the four mite species. Variation in mite densities between trees, even of the same variety, was quite high. The sample size (numbers of trees) required for assessing mite density can be calculated provided that an estimate of the coefficient of variation (S/X) is available.

2013 ◽  
Vol 56 (1-2) ◽  
pp. 109-115 ◽  
Author(s):  
Wojciech Warabieda ◽  
Mike Solomon

Movement behavior of two mite species: two-spotted spider mite (Tetranychus urticae) and European red mite (Panonychus ulmi) on leaves of some apple cultivars (´Greensleeves´, ´Spartan' and SA 455-2 selection) with different density of pubescence was analysed. Assessment of the leaf pubescence density was performed using an originally developed quick method based on digital pubescence mage analysis. For P.ulmi, both stop time and average speed did not depend on kind of leaf. In contrary. T.urticae revealed higher movement activity on slight pubescent leaves compared to leaves with high leaf hair density.


1967 ◽  
Vol 99 (7) ◽  
pp. 771-778 ◽  
Author(s):  
B. Parent

AbstractEcological studies, undertaken to determine the fluctuations of phytophagous mites and predators in apple orchards, were conducted in 1955, 1956, and 1957 at Rougemont, Que., in two plots sprayed only with fungicides for the control of apple scab, Venturia inaequalis (Cke) Wint., and in a third one sprayed, in addition to fungicides, with all insecticides needed for the control of destructive insects. Phytophagous mites were more numerous in the plot sprayed with insecticides than in plots sprayed only with fungicides, and densities of the mites in the latter plots were inversely proportional to densities of predators. A similar relationship existed in the insecticide plot between the amount of chemicals used and numbers of predators present. The principal mite predators were Typhlodromus rhenanus (Oudms.), most effective against the two-spotted spider mite, Tetranychus urticae Koch, and Mediolata mali (Ewing), most effective against the European red mite, Panonychus ulmi (Koch).


1962 ◽  
Vol 94 (7) ◽  
pp. 680-686 ◽  
Author(s):  
C. V. G. Morgan ◽  
P. T. Yee ◽  
F. E. Brinton

Sevin (1-naphthyl N-methylcarbamate) was first shown to have miticidal properties in 1957 when Allen et al. (1) found that it was moderately effective for the control oi the cyclamen mite, Steneotarsonmus pallidus (Banks), on strawberries. Subsequently it was demonstrated that Sevin would control the northern fowl mite, Ornithonyssus sylviarum (C. and F.) (7, 8, 9), suppress the brown mite, Bryobia arborea M. and A. (18), and the peach silver mite, Vasates cornutus (Banks) (18), and practically eliminate the predacious mite, Typhlodromus rhenanus Oudms. (18). It is not toxic to the European red mite, Panonychus ulmi (Koch) (18), the desert spider mite, Tetranychus desertorum Banks (4), and the two-spotted spider mite, Tetranychus telarius (L.) (6, 15); usually the use of Sevin for insect control will increase the numbers of these mites, and in this respect its effect is similar to that of DDT.


1990 ◽  
Vol 115 (5) ◽  
pp. 757-761 ◽  
Author(s):  
Kendrick N. Mobley ◽  
Richard P. Marini

Greenhouse-grown `Imperial Delicious' apple (Malus domestics Borkh.) and `Redhaven' peach (Prunus persica Batsch.) trees were inoculated during the summer with three densities of European red mite (ERM) (Panonychus ulmi Koch) and twospotted spider mite (TSM) (Tetranychus urticae Koch). As ERM- and TSM-days increased, net photosynthesis (Pn), transpiration (Tr), and total chlorophyll content (TCHL) of apple leaves decreased linearly. At similar densities, TSM was more damaging than ERM to apple leaf gas exchange. Water-use efficiency (WUE) of apple declined similarly with increasing mite-days for both mite species. Specific leaf weight (SLW) of apple increased with TSM-days. Pn, Tr, TCHL, and WUE of peach declined linearly with increasing ERM- and TSM-days, and the rates of decline were similar for both mite species. Mites did not affect peach SLW. These results indicate that greenhouse-grown peach is more tolerant than apple to mite feeding.


1962 ◽  
Vol 94 (11) ◽  
pp. 1222-1227 ◽  
Author(s):  
R. S. Downing

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.


2004 ◽  
Vol 29 (1) ◽  
Author(s):  
John C. Wise ◽  
Larry J. Gut ◽  
Gary Thornton

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Asgar Ebadollahi ◽  
Jalal Jalali Sendi ◽  
Alireza Aliakbar ◽  
Jabraeil Razmjou

Utilization of synthetic acaricides causes negative side-effects on nontarget organisms and environment and most of the mite species such as two spotted spider mite,Tetranychus urticaeKoch, are becoming resistant to these chemicals. In the present study, essential oils of fennel,Foeniculum vulgareMill., and lavender,Lavandula angustifoliaMiller, were hydrodistilled using Clevenger apparatus and chemical composition of these oils was analyzed by GC-MS. Anethole (46.73%), limonene (13.65%), andα-fenchone (8.27%) in the fennel essential oil and linalool (28.63%), 1,8-cineole (18.65%), and 1-borneol (15.94%) in the lavender essential oil were found as main components. Contact and fumigant toxicity of essential oils was assessed against adult females ofT. urticaeafter 24 h exposure time. The essential oils revealed strong toxicity in both contact and fumigant bioassays and the activity dependeds on essential oil concentrations. Lethal concentration 50% for the population of mite (LC50) was found as 0.557% (0.445–0.716) and 0.792% (0.598–1.091) in the contact toxicity and 1.876 μL/L air (1.786–1.982) and 1.971 μL/L air (1.628–2.478) in the fumigant toxicity for fennel and lavender oils, respectively. Results indicated thatF. vulgareandL. angustifoliaessential oils might be useful for managing of two spotted spider mite,T. urticae.


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