71 research outputs found
Recommended from our members
A Rapid Method to Assess Grape Rust Mites on Leaves and Observations from Case Studies in Western Oregon Vineyards
The grape rust mite [Calepitrimerus vitis (Acari: Eriophyidae)] is an important pest of grapevines (Vitis sp.) in grape-growing regions around the world. A rapid method for extracting eriophyoid mites was adapted from earlier studies to provide integrated pest management (IPM) consultants and commercial growers with a practical, efficient, and reliable tool to monitor grape rust mites in vineyards and nursery stock vines. The rinse in bag (RIB) method allows quick extraction of mites from young shoots or from leaves using 35% to 70% ethanol or isopropanol in a sealable plastic bag. The RIB method recovered 85% of grape rust mites from single leaves in the first rinse. The method is useful to estimate grape rust mites on young shoots (≤10 cm length), although recovery of grape rust mites (average ranging from 35% to 81%) was lower because of a higher density of trichomes on young shoots as compared with leaf samples. The RIB method was not effective to assess grape rust mites within dormant buds, so a separate method using a blender to disrupt tissues and extract mites in alcohol was developed. The RIB method was used to determine grape rust mite abundance with leaf symptoms in commercial vineyards and nursery stock vines. The earliest visible symptom of grape rust mite damage on leaves in the summer was the development of stippling that is distinct from the type of damage caused by other grapevine pests. The stippling is described as numerous clear zones of small diameter (resembling pinholes) that are visible when a leaf is backlit. The severity of stippling was related to the number of grape rust mites present on leaves, with >600 occurring on leaves with severe stippling symptoms. In commercial vineyard case studies, the RIB method was used over two seasons and revealed that grape rust mite populations remained on leaves until postharvest, and foliar applications of wettable sulfur reduced grape rust mite populations on leaves.This is the publisher’s final pdf. The published article is copyrighted by the American Society for Horticultural Science and can be found at: http://horttech.ashspublications.org/Keywords: Scouting technique, Eriophyidae, Leaf stippling, Extraction method, Vitis vinifera, Calepitrimerus vitisKeywords: Scouting technique, Eriophyidae, Leaf stippling, Extraction method, Vitis vinifera, Calepitrimerus viti
Recommended from our members
2017 pest management guide for wine grapes in Oregon
Second revision March 24, 2017.
Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalogThis pest management guide is developed for use by vineyard managers in Oregon. It provides recommendations for chemicals, formulations, and usage rates of products that are intended to prevent, manage, and control vineyard diseases, insects, mites, weeds, and vertebrate pests. When considering a pesticide, evaluate its efficacy and its impact on beneficial arthropods, honey bees, and the environment. Not all registered pesticides are listed in this guide. These recommendations are based on research, label directions, and vineyard-use experience for Oregon
Recommended from our members
Population Density and Phenology of Tetranychus urticae (Acari: Tetranychidae) in Hop is Linked to the Timing of Sulfur Applications
The twospotted spider mite, Tetranychus urticae Koch, is a worldwide pest of numerous agronomic and horticultural plants. Sulfur fungicides are known to induce outbreaks of this pest on several crops, although mechanisms associated with sulfur-induced mite outbreaks are largely unknown. Studies were conducted during 2007–2009 in Oregon and Washington hop yards to evaluate the effect of timing of sulfur applications on T. urticae and key predators. In both regions, applications of sulfur made relatively late in the growing season (mid-June to mid-July) were associated with the greatest exacerbation of spider mite outbreaks, particularly in the upper canopy of the crop. The severity of mite outbreaks was closely associated with sulfur applications made during a relatively narrow time period coincident with the early exponential phase of spider mite increase and rapid host growth. A nonlinear model relating mean cumulative mite days during the time of sulfur sprays to the percent increase in total cumulative mite days (standardized to a nontreated plot) explained 58% of the variability observed in increased spider mite severity related to sulfur spray timing. Spatial patterns of spider mites in the Oregon plots indicated similar dispersal of motile stages of spider mites among leaves treated with sulfur versus nontreated leaves; however, in two of three years, eggs were less aggregated on leaves of sulfur-treated plants, pointing to enhanced dispersal. Apart from one experiment in Washington, relatively few predatory mites were observed during the course of these studies, and sulfur-induced mite outbreaks generally occurred irrespective of predatory mite abundance. Collectively, these studies indicate sulfur induces mite outbreaks through direct or indirect effects on T. urticae, mostly independent of predatory mite abundance or toxicity to these predators. Avoidance of exacerbation of spider mite outbreaks by sulfur sprays was achieved by carefully timing applications to periods of low spider mite abundance and slower host development, which is generally early to mid-spring for hop.Keywords: pest resurgence, Humulus lupulus, Podosphaera macularis, conservation biological controlKeywords: pest resurgence, Humulus lupulus, Podosphaera macularis, conservation biological contro
Recommended from our members
Distribution and activity of Drosophila suzukii in cultivated raspberry and surrounding vegetation
Spotted wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), may utilize wild ‘Himalaya’ blackberry (HB) Rubus armeniacus Focke or other non-crop plants as refugia and possibly exploit adjacent field margins before colonizing cultivated fruiting crops. Studies were conducted to determine the role of field margins containing HB and their effect on D. suzukii activity, density and distribution in an adjacent commercial red raspberry crop. One-ha plots adjacent to field margins containing HB or known non-host (NH) grass crops were established in 2011 and 2012 and replicated three times. Each plot contained two transects with monitoring traps for D. suzukii in the field margin (0 m) and spaced approximately 10 (crop boundary), 40, 70 and 100 m into the adjacent crop (n = 10 traps/plot). Field margin vegetation was treated with a 10% chicken egg white mark solution weekly from pre-harvest until the end of harvest using a cannon sprayer. Adult D. suzukii were collected from traps weekly and analysed for the presence of the egg white mark using an egg white-specific enzyme-linked immunosorbent assay (ELISA). During both years, marked flies and total flies were captured in higher numbers in HB field margins, whereas virtually no flies were captured in field margins containing no known alternative host. Similarly, more flies were captured in the crop near HB than near NH. Spatial Analysis by Distance IndicEs (SADIE) and mean D. suzukii trap captures additionally displayed significantly higher fly densities in the raspberry field near HB than near NH. These results suggest that HB may contribute to elevated D. suzukii populations and pest pressure in comparison with field margins containing no known alternate host vegetation for D. suzukii. Having closely adjacent non-crop alternate host landscapes may result in increased D. suzukii pest pressure
Recommended from our members
Prevención y manejo del virus del enrollamiento de la hoja y de los piojos harinosos en viñedos del estado de Oregon
Published January 2010. Reviewed January 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalogKeywords: grapevine leafroll virus, mealybugs, grape vineyardsKeywords: grapevine leafroll virus, mealybugs, grape vineyard
Recommended from our members
Grapevine leafroll virus and mealybug prevention and management in Oregon vineyards
Published October 2009. Reviewed January 2014. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalogKeywords: grapevine leafroll virus, grape vineyards, mealybug
Recommended from our members
Evaluation of Monitoring Traps for Drosophila suzukii (Diptera: Drosophilidae) in North America
Drosophila suzukii Matsumura (Diptera: Drosophilidae), a recent invasive pest of small and stone fruits, has been detected in more than half of the U.S. states, and in Canada, Mexico, and Europe. Upon discovery, several different trap designs were recommended for monitoring. This study compared the trap designs across seven states/provinces in North America and nine crop types. Between May and November 2011, we compared a clear cup with 10 side holes (clear); a commercial trap with two side holes (commercial); a Rubbermaid container with mesh lid and rain tent (Haviland), and with 10 side holes and no tent (modified Haviland); a red cup with 10 side holes (red); and a white container with mesh lid and rain tent (Van Steenwyk). Although fly catches among traps varied per site, overall, the Haviland trap caught the most D. suzukii, followed by the red, Van Steenwyk, and clear trap. The modified Haviland and commercial trap had low captures. Among five crop types in Oregon, a clear cup with mesh sides (Dreves) also was tested and caught the most flies. Traps with greater entry areas, found in mesh traps, caught more flies than traps with smaller entry areas. In terms of sensitivity and selectivity, traps that caught more flies likewise caught flies earlier, and all traps caught 26-31% D. suzukii out of the total Drosophila captured. Future trap improvements should incorporate more entry points and focus on selective baits to improve efficiency and selectivity with regard to the seasonal behavior of D. suzukii.This is the publisher’s final pdf. The article is published by the Entomological Society of America. It can be found at: http://www.entsoc.org/Pubs/Periodicals/JE
Recommended from our members
Trap Designs for Monitoring Drosophila suzukii (Diptera: Drosophilidae)
Drosophila suzukii (Matsumura), an invasive pest of small and stone fruits, has been recently detected in 39 states of the United States, Canada, Mexico, and Europe. This pest attacks ripening fruit, causing economic losses including increased management costs and crop rejection. Ongoing research aims to improve the efficacy of monitoring traps. Studies were conducted to evaluate how physical trap features affect captures of D. suzukii. We evaluated five colors, two bait surface areas, and a top and side position for the fly entry point. Studies were conducted at 16 sites spanning seven states and provinces of North America and nine crop types. Apple cider vinegar was the standard bait in all trap types. In the overall analysis, yellow-colored traps caught significantly more flies than clear, white, and black traps; and red traps caught more than clear traps. Results by color may be influenced by crop type. Overall, the trap with a greater bait surface area caught slightly more D. suzukii than the trap with smaller area (90 vs. 40 cm²). Overall, the two traps with a side-mesh entry, with or without a protective rain tent, caught more D. suzukii than the trap with a top-mesh entry and tent.This article is the copyright property of the Entomological Society of America and may not be used for any commercial or other private purpose without specific written permission of the Entomological Society of America. This is the publisher’s final pdf. The published article can be found at: http://www.entsoc.org/Pubs/Periodicals/EE.Keywords: monitoring, spotted wing drosophila, color, vinegar fly, trap designKeywords: monitoring, spotted wing drosophila, color, vinegar fly, trap desig
Recommended from our members
2010 Seed production research at Oregon State University, USDA-ARS cooperating
- …