scholarly journals Stability and Resiliency of Biological Control of the Twospotted Spider Mite (Acari: Tetranychidae) in Hop

2019 ◽  
Vol 48 (4) ◽  
pp. 894-902 ◽  
Author(s):  
A E Iskra ◽  
J L Woods ◽  
D H Gent
Keyword(s):  
Biological Control ◽  
Natural Enemies ◽  
Nitrogen Fertilization ◽  
Spider Mite ◽  
Fertilization Rate ◽  
Conservation Biological Control ◽  
Spider Mites ◽  
Economic Damage ◽  
Twospotted Spider Mite ◽  
Twospotted Spider

Abstract The twospotted spider mite (Tetranychus urticae Koch) is a common pest in agricultural and ornamental crops. This pest can be controlled by resident predatory arthropods in certain situations. This research quantified the stability and resiliency of established conservation biological control of the twospotted spider mite in hop over a 5-yr period associated with nitrogen fertilization rate and use of a broad-spectrum insecticide. Biological control generally was stable and resilient over a sixfold range of nitrogen fertilization rates, and in only 1 of 5 yr did elevated nitrogen rates significantly affect populations of spider mites. In contrast, one application of the insecticide bifenthrin was associated with disruption of biological control and a severe outbreak of spider mites. The complex of natural enemies suppressed the outbreak during the same year in which bifenthrin was applied, but only after populations of spider mites exceeded levels associated with economic damage. However, in the following year the system returned to an equilibrium state where spider mites were suppressed below economically damaging levels. Therefore, conservation biological control in hop appears stable and robust to factors such as nitrogen fertilization that increase reproductive rates of spider mites but may be sensitive to factors such as nonselective insecticides that are lethal to natural enemies. Conservation biological control can be considered resilient to a single use of a nonselective insecticide in the year following the application, but not within the year of application.

Effect of Barren Soil Borders and Weed Border Treatments on Movement of the Twospotted Spider Mite into Peanut Fields1,2,3

1984 ◽  
Vol 11 (1) ◽  
pp. 52-55 ◽  
Author(s):  
L. S. Boykin ◽  
W. V. Campbell ◽  
L. A. Nelson
Keyword(s):  
Spider Mite ◽  
Field Tests ◽  
Spider Mites ◽  
Twospotted Spider Mite ◽  
Field Cage ◽  
Arachis Hypogaea L ◽  
Barren Soil ◽  
Tetranychus Urticae Koch ◽  
Over Time ◽  
Twospotted Spider

Abstract Barren soil borders, weed border treatments, and caged barren soil were evaluated for their effect on movement of the twospotted spider mite, Tetranychus urticae Koch, into peanut (Arachis hypogaea L.) fields. In field cage tests when a 3, 4.5, or 6 m strip of barren soil separated a source of mite-infestation from initially mite-free peanut, mite damage to peanut was inversely related to the distance of barren soil crossed. In uncaged field tests, similar barren soil borders did not prevent mite movement into peanut fields, however, the number of mites were inversely related to the distance from the field border. There were no significant differences among weed border treatments and total numbers of mites entering peanut fields over time. There were, however, differences among weed border treatments on early mite movement and establishment trends into peanut fields. Mowing weed borders significantly increased the number of aerially dispersing twospotted spider mites within the adjacent peanut field.

scholarly journals Effect of Fungicides and Miticides with Mitochondria Electron Transport Inhibiting Activity on the Twospotted Spider Mite, Tetranychus urticae (Acari: Tetranychidae)

HortScience ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 687-689 ◽  
Author(s):  
Raymond A. Cloyd ◽  
Cindy L. Galle ◽  
Stephen R. Keith ◽  
Kenneth E. Kemp
Keyword(s):  
Electron Transport ◽  
Tetranychus Urticae ◽  
Spider Mite ◽  
Adult Life ◽  
Spider Mites ◽  
Twospotted Spider Mite ◽  
Negative Effects ◽  
Percentage Mortality ◽  
Horticultural Crops ◽  
Twospotted Spider

The twospotted spider mite, Tetranychus urticae, is a major arthropod pest of many greenhouse-grown horticultural crops. Greenhouse producers use a variety of miticides to suppress twospotted spider mite populations. A group of miticides known as mitochondria electron transport inhibitors or METIs include acequinocyl, fenpyroximate, and pyridaben. In addition, there are strobilurin-based fungicides such as azoxystrobin, kresoxim-methyl, and trifloxystrobin that are also known as METIs. We conducted a study to determine if these METI fungicides had any miticidal properties against the nymph and adult stages of the twospotted spider mite. The designated treatments were applied to marigold (Tagetes erecta) plants naturally infested with twospotted spider mites. Assessments of live and dead twospotted spider mite nymphs and adults were conducted 3, 7, and 14 days after applying the treatments. None of the METI fungicides had any activity against the nymph and adult life stages of the twospotted spider mite, with percentage mortality values <18%. The METI miticides appeared to be more effective against twospotted spider mite nymphs than the adults based on percentage mortality values across the three evaluation periods (35.2% to 100% for nymphs and 11.4% to 87.9% for adults). This study demonstrated that the strobilurin-based fungicides have negligible negative effects on twospotted spider mites.

scholarly journals Phosphine fumigation to disinfest kiwifruit

2012 ◽  
Vol 65 ◽  
pp. 35-43 ◽  
Author(s):  
L.E. Jamieson ◽  
N.E.M Page-Weir ◽  
A Chhagan ◽  
D.W. Brash ◽  
D. Klementz ◽  
...  
Keyword(s):  
New Zealand ◽  
Low Temperature ◽  
Methyl Bromide ◽  
Spider Mite ◽  
Scale Insect ◽  
Spider Mites ◽  
Scale Insects ◽  
Life Stages ◽  
Twospotted Spider Mite ◽  
Twospotted Spider

Global use of phosphine as a fumigant has increased in response to the need to replace methyl bromide and with the improved formulations ECO2FUME and VAPORPH3OS Phosphine is registered as a postharvest fumigant on kiwifruit in New Zealand and has been used commercially to reduce the risk of detecting live pests Scale insects mealybugs and diapausing twospotted spider mites were exposed to a range of phosphine treatments A 48h low temperature (1746C) fumigation (64083311 ppm) achieved 100 mortality of all life stages of oleander scale insects while a 12h exposure killed all longtailed mealybug life stages A 36h low temperature (2533C) fumigation (43322712 ppm) treatment achieved 100 mortality of all greedy scale insect life stages A 48 to 96h treatment (36001200 ppm) at 115C caused 913100 mortality of diapausing twospotted spider mite adults Use of phosphine as a commercial treatment for kiwifruit is discussed

scholarly journals Fragaria Resistance to Spider Mites at Three Locations in the United States

HortScience ◽  
1995 ◽  
Vol 30 (5) ◽  
pp. 1068-1069 ◽  
Author(s):  
Carl H. Shanks ◽  
Craig K. Chandler ◽  
Edgar D. Show ◽  
Patrick P. Moore
Keyword(s):  
United States ◽  
Tetranychus Urticae ◽  
Spider Mite ◽  
The United States ◽  
Spider Mites ◽  
Twospotted Spider Mite ◽  
Relative Resistance ◽  
Twospotted Spider

Eleven clones of Fragaria spp. were tested for resistance to the twospotted spider mite, Tetranychus urticae Koch, at Dover, Fla.; Watsonville, Calif.; and Vancouver, Wash. Ten clones, which had been selected previously as being mite-resistant, had generally the same relative resistance when compared to susceptible `Totem' at all three of the widely separated locations. It appears that Fragaria clones selected for resistance to spider mites at one location likely will be resistant elsewhere, in spite of environmental differences.

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