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The two-spotted spider mite, Tetranychus urticae Koch, is a constant threat to sustainable production of numerous economically important crops globally. Management of T. urticae is heavily reliant on the application of synthetic acaricides. However, T. urticae has rapidly developed resistance to most of the acaricides available for its control due to its very broad host plant range, extremely short lifecycle, high fecundity, arrhenotokous parthenogenesis, and overwintering strategy. Despite the recent progress in identifying genetic changes/markers associated with resistance toward some commonly used acaricides for T. urticae, there is still limited studies that select and apply these markers in field populations to guide sustainable pest management strategy design. Temporal and spatial characterization of acaricide-resistant phenotypes and their underlying mechanisms are crucial for the design and implementation of successful and sustainable integrated mite management programs. This review highlights the current acaricide resistance status of field-collected T. urticae populations and the underlying molecular mechanisms of resistance. Our review found that some genetic mutations in target sites and/or overexpression of metabolic genes confer resistance in geographically exclusive populations, while some resistance markers appear to be specific to populations at biogeographical areas. Thus, there is a need for locally based coordinated efforts to understand the mechanisms of resistance present in endemic T. urticae populations. Moreover, we discuss a prospective template for designing an effective acaricide resistance management program within various agroecosystems.

Pseudococcus maritimus status as an economic pest increased substantially after it was identified as a key vector of most grape vine leafroll-associated viruses (GLRaVs). Of these viruses, GLRaV-3 is the most economically destructive. Current control recommendations for slowing the spread of GLRaVs include one to two applications of insecticides to reduce vector populations. Systemic insecticides require the insect to feed before death or paralysis occurs. It was unknown if systemic insecticides could paralyze or kill P. maritimus quickly enough to reduce their ability to vector GLRaVs. Hence, we tested imidacloprid, spirotetramat, and flupyradifurone to see if these insecticides would have any effect on P. maritimus’ efficiency to vector GLRaV-3 on treated grapevines. We conclude that these systemic insecticides do not convey any additional protection to grapevines. However, these insecticides are still useful for reducing vector populations and indirectly reduce the potential spread of GLRaVs among vines in vineyards.

The polyphagous pest Tetranychus urticae feeds on over 1100 plant species including highly valued economic crops such as hops (Humulus lupulus). In the key hop production region of the Pacific Northwest of the USA, T. urticae is one of the major arthropod pests. Over the years, T. urticae control has been dominated by the application of various acaricides. However, T. urticae quickly adapts to these acaricides by developing resistance. Here, we determined resistance ratios of T. urticae populations in hops to three acaricides: etoxazole, fenpyroximate, and spirodiclofen. The mechanisms underlying resistance to these and three other acaricides were investigated in 37 field-collected T. urticae populations using a comprehensive diagnostic approach. Our data showed that T. urticae populations exhibited complex adaptation patterns to acaricides. Resistance to abamectin, fenpyroximate, and spirodiclofen by enhanced target metabolic detoxification gene(s) was identified in 100%, 50%, and 20% of populations tested, respectively. Resistance to bifenthrin, bifenazate, and etoxazole by target site insensitivity was pervasive among tested populations. Our study provides new information in understanding the complexity of T. urticae adaptation to multiple acaricides, which will help in designing sustainable pest control strategies for T. urticae on hops and other economically valuable crops.

The western grape leafhopper (Erythroneura elegantula Osborn) and the Virginia creeper leafhopper (Erythroneura ziczac Walsh) are the two leafhopper pests frequently observed in Washington State vineyards. Organic viticulturists have difficulties controlling these leafhopper pests, and outbreaks can result in economic loss. We vineyard-tested the efficacy of several candidate bioinsecticides and conventional insecticides against the western grape leafhopper and the Virginia creeper leafhopper. This study included the initial testing of several alternative candidate insecticides for leafhopper control. Controlled laboratory bioassays also were completed, and the 50% and 90% lethal concentrations were calculated for the nonsystemic insecticides tested. Of the bioinsecticides tested, pyrethrum (PyganicTM, Valent Bioscience Corporation, Libertyville, IL) was the only product that provided effective control of leafhoppers in both the vineyard and laboratory components of this study. In vineyard effic...

Quantitative real-time PCR (qRT-PCR) is an extensively used, high-throughput method to analyze transcriptional expression of genes of interest. An appropriate normalization strategy with reliable reference genes is required for calculating gene expression across diverse experimental conditions. In this study, we aim to identify the most stable reference genes for expression studies of xenobiotic adaptation in Tetranychus urticae, an extremely polyphagous herbivore causing significant yield reduction of agriculture. We chose eight commonly used housekeeping genes as candidates. The qRT-PCR expression data for these genes were evaluated from seven populations: a susceptible and three acaricide resistant populations feeding on lima beans, and three other susceptible populations which had been shifted host from lima beans to three other plant species. The stability of the candidate reference genes was then assessed using four different algorithms (comparative ΔCt method, geNorm, NormFinder, and BestKeeper). Additionally, we used an online web-based tool (RefFinder) to assign an overall final rank for each candidate gene. Our study found that CycA and Rp49 are best for investigating gene expression in acaricide susceptible and resistant populations. GAPDH, Rp49, and Rpl18 are best for host plant shift studies. And GAPDH and Rp49 were the most stable reference genes when investigating gene expression under changes in both experimental conditions. These results will facilitate research in revealing molecular mechanisms underlying the xenobiotic adaptation of this notorious agricultural pest.

A monitoring program for a recently introduced vinegar fly, Drosophila suzukii Matsumura, 1931, was conducted in south-central Washington State, U.S.A. from March 2011 to November 2013. Along with D. suzukii, a complex of nine additional Drosophila Fallen, 1815 species were captured in baited traps and identified to species. The Drosophila were captured in Nalgene® and Haviland traps baited with apple cider vinegar or a sugar yeast mixture that were distributed among seven different horticultural crops or unmanaged habitats. All flies captured were identified to species and quantified for each sampling period. The species identified and quantified included D. busckii Coquillett, 1901, D. funebris Fabricius, 1787, D. hydei Sturtevant,1921, D. immigrans Sturtevant, 1921, D. melanogaster Meigen, 1830, D. simulans Sturtevant, 1919, D. obscura Fallen, 1823, D. subobscura Collin, 1936, D. subquinaria Spencer, 1942 and D. suzukii. The predominant species in 2011 were the obscura group and D. hydei. In ...

This study was conducted to determine whether beers produced with late (i.e., after kettle-boil) additions of hops Humulus lupulus cultivars Cascade or Chinook (either dry hopped with whole or pell...

The two-spotted spider mite,Tetranychus urticae, is a polyphagous pest feeding on over 1,100 plant species, including numerous highly valued economic crops. The control ofT. urticaelargely depends on the use of acaricides, which leads to pervasive development of acaricide resistance. Cytochrome P450-mediated metabolic detoxification is one of the major mechanisms of acaricide resistance inT. urticae. NADPH-cytochrome P450 reductase (CPR) plays as a crucial co-factor protein that donates electron(s) to microsomal cytochrome P450s to complete their catalytic cycle. This study seeks to understand the involvement of CPR in acaricide resistance inurticae. The full-length cDNA sequence ofT. urticae’s CPR (TuCPR) was cloned and characterized.TuCPRwas ubiquitously transcribed in different life stages ofT. urticaeand the highest transcription was observed in the nymph and adult stages.TuCPRwas constitutively over-expressed in six acaricide resistant populations compared to a susceptible one.TuCPRtranscriptional expression was also induced by multiple acaricides in a time-dependent manner. Down-regulation ofTuCPRvia RNA interference (RNAi) inT. urticaeled to reduced enzymatic activities of TuCPR and cytochrome P450s, as well as a significant reduction of resistance to multiple acaricides, abamectin, bifenthrin, and fenpyroximate. The outcome of this study highlights CPR as a potential novel target for eco-friendly control ofT. urticaeand other related plant-feeding pests.HighlightsPipernoyl butoxide significantly reduced abamectin, bifenthrin, and fenpyroximate resistance inT. urticaepopulationsT. urticae’s cytochrome P450 reductase (TuCPR) was cloned, sequenced and phylogenetically analyzedAbamectin, bifenthrin and fenpyroximate treatment induced TuCPR gene expressionSilencing ofTuCPRinT. urticaecaused a reduction in acaricide resistance

Larvae of Prionus californicus Motschulsky feed on the roots of many woody perennial plants and are economically important pests of hop Humulus lupulus L. (Urticales: Cannabaceae) and sweet cherry Prunus avium (L.) (Magnoliopsida: Rosaceae) in the United States Pacific Northwest and Intermountain West. Adult males are strongly attracted to a volatile sex pheromone, (3R,5S)-3,5-dimethyldodecanoic acid, produced by females. Here, we summarize the results of field experiments evaluating the synthetic pheromone in a blend of all four possible stereoisomers as a means for managing P. californicus in hop yards and sweet cherry orchards by mating disruption (MD). Mean capture of male beetles was lower, in all 3 yr of the study, from plots in commercial hop yards and sweet cherry orchards treated with synthetic P. californicus pheromone than from similar, untreated plots. Although trap catch was lower in sweet cherry, relative differences between trap catches from MD and nonmating disruption plots were similar to that seen in hop yards. The number of P. californicus larvae recovered from plots in hop yards treated for three consecutive growing seasons with synthetic pheromone was lower than in similar plots that were not treated with the pheromone or treated with the soil fumigant ethoprop. Our research demonstrates that deployment of synthetic P. californicus pheromone effectively reduces mate-finding by males, can effectively reduce larvae populations in pheromone-treated hop yards, and thus, has excellent potential for managing P. californicus in hop, sweet cherry, and perhaps in other crops where it or Prionus species are pests.

Tetranychus urticae Koch is a generalist pest of economic crops and is notorious for its rapid development of acaricide resistance. This poses a significant threat to the sustainability of integrated pest management (IPM) in cropping systems plagued by T. urticae. It is critical to evaluate the resistance status of T. urticae populations on crops and identify any underlying resistance mechanisms. This study investigated the efficacy of five major acaricides on T. urticae populations on peppermint and silage corn in the Pacific Northwestern United States and identified the underlying resistance mechanisms. Significant variations in acaricide resistance status of T. urticae populations were identified to abamectin, bifenthrin, fenpyroximate, hexythiazox, and spirodiclofen. In most cases, T. urticae populations from silage corn exhibited greater levels of acaricide resistance relative to peppermint populations. We detected known target-site mutations: F1534S and F1538I (conferring resistance to bifenthrin), G126S (linked with resistance to bifenazate), and I1017 (conferring resistance to hexythiazox and etoxazole) in 10, 90, and 90% of the populations, respectively, from peppermint fields. These four mutations were identified in all the populations collected from silage corn fields. Significantly higher transcript levels of metabolic genes associated with resistance to abamectin, fenpyroximate, and spirodiclofen were observed in some T. urticae populations collected from both peppermint and silage corn fields. This study provides evidence of multiple resistance to diverse active ingredients in field populations of T. urticae and the reliability of known molecular markers for active acaricide resistance monitoring. The observed resistance pattern will help in designing a sustainable IPM program for T. urticae.

Tetranychus urticae Koch is a generalist pest of economic crops and is notorious for its rapid development of acaricide resistance. This poses a significant threat to the sustainability of integrated pest management (IPM) in cropping systems plagued by T. urticae. It is critical to evaluate the resistance status of T. urticae populations on crops and identify any underlying resistance mechanisms. This study investigated the efficacy of five major acaricides on T. urticae populations on peppermint and silage corn in the Pacific Northwestern United States and identified the underlying resistance mechanisms. Significant variations in acaricide resistance status of T. urticae populations were identified to abamectin, bifenthrin, fenpyroximate, hexythiazox, and spirodiclofen. In most cases, T. urticae populations from silage corn exhibited greater levels of acaricide resistance relative to peppermint populations. We detected known target-site mutations: F1534S and F1538I (conferring resistance to bifenthrin), G126S (linked with resistance to bifenazate), and I1017 (conferring resistance to hexythiazox and etoxazole) in 10, 90, and 90% of the populations, respectively, from peppermint fields. These four mutations were identified in all the populations collected from silage corn fields. Significantly higher transcript levels of metabolic genes associated with resistance to abamectin, fenpyroximate, and spirodiclofen were observed in some T. urticae populations collected from both peppermint and silage corn fields. This study provides evidence of multiple resistance to diverse active ingredients in field populations of T. urticae and the reliability of known molecular markers for active acaricide resistance monitoring. The observed resistance pattern will help in designing a sustainable IPM program for T. urticae.

The grape mealybug, Pseudococcus maritimus (Ehrhorn; Hemiptera: Pseudococcidae), is the primary vector of Grapevine Leafroll associated Viruses (GLRaVs) in Washington State vineyards. Rearing laboratory colonies of grape mealybug has proven difficult. Several host plants were tested to determine their suitability for use as an alternate host plants for laboratory colonies of grape mealybug. Of the plants tested, colonies of grape mealybug were successful on pumpkin (Cucurbita pepo cv 'Connecticut field') leaves and vines. Mealybugs were able to develop from the crawler stage, through developmental instars, and adults were able to reproduce viable offspring. To date this is the only successful study to raise grape mealybugs on a cucurbit. Pumpkin appears to be a viable alternate host plant for laboratory colonies of the grape mealybug.

BACKGROUND Knockdown resistance (kdr) has been identified as a main mechanism against pyrethroid insecticides in many arthropod pests including in the onion thrips, Thrips tabaci. To characterize and identify pyrethroid-resistance in onion thrips in Washington state, we conducted insecticide bioassays and sequenced a region of the voltage gated sodium channel gene from several different T. tabaci populations. RESULTS Field collected Thrips tabaci were found to have large variations in resistance to the pyrethroid insecticide lambda-cyhalothrin. We identified two single nucleotide substitutions in our analysis of a partial sequence of the T. tabaci voltage-gated sodium channel gene. One mutation resulted in the non-synonymous substitution of methionine with leucine (M918L), which is well known to be responsible for super knockdown resistance in some pest species. Another non-synonymous substitution, a valine (GTT) to alanine (GCT) replacement at amino acid 1010 (V1010A) was identified in our study and was associated with lambda-cyhalothrin resistance. CONCLUSION We have characterized a known kdr mutation and identified a novel mutation in the voltage-gated sodium channel gene of Thrips tabaci associated with resistance to lambda-cyhalothrin. This gene region and these mutations are expected to be useful in the development of a diagnostic test to detect kdr resistance in many onion thrips populations. © 2013 Society of Chemical Industry

Background Face flies, Musca autumnalis De Geer (Diptera: Muscidae), and houseflies, Musca domestica L. (Diptera: Muscidae), have a significant impact on livestock and dairy production throughout North America. Pyrethroid insecticide efficacy can be affected by exposure to direct sunlight, and the rate of photodegradation is substrate and formulation dependent. Insecticide-treated netting (ITN) is finding new applications in crop and livestock production systems. A baseline study using long-duration no-choice assays has been carried out to gauge the effectiveness of ITN treated with β-cyfluthrin, λ-cyhalothrin and bifenthrin on face flies and houseflies. Results After 12 weeks in direct sunlight, ITN treated with β-cyfluthrin was still highly insecticidal to face flies and houseflies, producing 100% mortality in petri dish assays. However, sunlight reduced the insecticidal activity of λ-cyhalothrin, with 3% of face flies and 50% of houseflies surviving after exposure to ITN that had been deployed for 10 weeks. Insecticidal activity was greatly reduced on bifenthrin-treated netting, with 20% of face flies and 50% of houseflies surviving in assays with netting deployed for only 3 weeks. Conclusion With careful choice of the pyrethroid applied, treated netting could be an important component of livestock integrated pest management programs focused on sustainable practices. © 2013 Society of Chemical Industry

Effects of heat treatments on activation and infectivity of Taenia hydatigena eggs were assessed. Eggs containing oncospheres were used for in vitro and in vivo studies to determine the response to 5min of heat treatment, ranging from room temperature (22°C) to 60°C. The study demonstrated 99.47% and 100% reduction in oncosphere activation or infectivity after 5min of heat treatment at 60°C and 57.38°C under in vitro and in vivo conditions, respectively. Similar results between the two approaches indicted the appropriateness of the in vitro methods to identify oncosphericidal treatments of practical significance. Similar heat treatments may also be effective against Taenia saginata and help to reduce occurrence of beef cysticercosis.

A Taenia hydatigena model was used to assess the effect 0, 7, 14, 21, and 28 days of ensilation of minced potato on viability of tapeworm eggs. For infection of lambs, 2,000 T. hydatigena eggs were ensiled for 0, 7, 14, 21 and 28 days in minced potato at 22°C and fed to recently weaned lambs (29.9±0.76 kg). At slaughter, no cysticerci were recovered from lambs infected with eggs ensiled for 28 days while a mean of 5.0±5.0 cysticerci (0.25% of the initial egg dose) were recovered from lambs infected with eggs ensiled for 21 days. For lambs fed eggs ensiled for 0 days (control), 359.3±55.6 cysticerci were recovered (18.0% of the initial egg dose). Regression analysis revealed that a 99.9% reduction in viability was attained after 18.59 days of ensilation.

The increased urbanization of a growing global population makes imperative the development of sustainable integrated pest management (IPM) strategies for urban pest control. This emphasizes pests that are closely associated with the health and wellbeing of humans and domesticated animals. Concurrently there are regulatory requirements enforced to minimize inadvertent exposures to insecticides in the urban environment. Development of insecticide resistance management (IRM) strategies in urban ecosystems involves understanding the status and mechanisms of insecticide resistance and reducing insecticide selection pressure by combining multiple chemical and non-chemical approaches. In this review, we will focus on the commonly used insecticides and molecular and physiological mechanisms underlying insecticide resistance in six major urban insect pests: house fly, German cockroach, mosquitoes, red flour beetle, bed bugs and head louse. We will also discuss several strategies that may prove promising for future urban IPM programs.

A field experiment was conducted from 2008-2010 to evaluate sustained deficit irrigation impacts on biomass, oil yields, and oil components of peppermint (Mentha piperita L. Black Mitchum) in the semi arid Pacific Northwest, USA. A line-source sprinkler design was used to create gradually increasing deficit irrigation treatments. Irrigation scheduled using a soil water balance method so as to replenish the soil water deficit in a 100cm deep managed root zone two to three times a week in the fully irrigated treatment plots adjacent to the sprinkler lines. The plots furthest from the sprinkler line received minimal supplemental irrigation. The results show that biomass hay yield was significantly affected by water availability. Oil yields also decreased with increasing deficit irrigation from 103 to 26 kg/ha in the only harvest obtained from all test plots. Peak water use of peppermint was about 580 mm per harvest with significant inter-year variation. Of the two harvests per year the peak water use for the second harvest was considerably lower than that for the first harvest due to a shorter growth period. The second harvest was significantly less than the first harvest suggesting that under sustained deficit irrigation a second harvest is not profitable. Hay water productivity of 2.55 to 6.04 kg/m3 was realized while oil water productivity of 0.01 kg/m3 was realized across all treatments. The major peppermint oil components were significantly affected by irrigation level. There is potential to improve water use efficiency and crop productivity using sustained deficit irrigation but the significant loss of plant stand makes the practice inadvisable for peppermint.

The two-spotted spider mite, Tetranychus urticae Koch is a major pest that feeds on >1,100 plant species. Many perennial crops including hop (Humulus lupulus) are routinely plagued by T. urticae infestations. Hop is a specialty crop in Pacific Northwest states, where 99% of all U.S. hops are produced. To suppress T. urticae, growers often apply various acaricides. Unfortunately T. urticae has been documented to quickly develop resistance to these acaricides which directly cause control failures. Here, we investigated resistance ratios and distribution of multiple resistance-associated mutations in field collected T. urticae samples compared with a susceptible population. Our research revealed that a mutation in the cytochrome b gene (G126S) in 35% tested T. urticae populations and a mutation in the voltage-gated sodium channel gene (F1538I) in 66.7% populations may contribute resistance to bifenazate and bifenthrin, respectively. No mutations were detected in Glutamate-gated chloride channel subunits tested, suggesting target site insensitivity may not be important in our hop T. urticae resistance to abamectin. However, P450-mediated detoxification was observed and is a putative mechanism for abamectin resistance. Molecular mechanisms of T. urticae chemical adaptation in hopyards is imperative new information that will help growers develop effective and sustainable management strategies.

A simple molecular tool was developed and tested to identify seven mealybug species found in North American vineyards: Pseudococcus maritimus Ehrhorn, Pseudococcus viburni (Signoret), Pseudococcus longispinus (Targioni-Tozzeti), Pseudococcus calceolariae (Maskell), Planococcus ficus (Signoret), Planococcus citri (Risso), and Ferrisia gilli Gullan. The developed multiplex PCR is based on the mitochondrial cytochrome c oxidase subunit one gene. In tests, this single-step multiplex PCR correctly identified 95 of 95 mealybug samples, representing all seven species and collected from diverse geographic regions. To test the sensitivity, single specimen samples with different Pl. ficus developmental stages (egg to adult female and adult male) were processed PCR and the resulting output provided consistent positive identification. To test the utility of this protocol for adult males caught in sex baited pheromone traps, Pl. ficus adult males were placed in pheromone traps, aged at a constant temperature of 26±2°C, and processed with the multiplex each day thereafter for 8 d. Results showed consistent positive identification for up to 6 d (range, 6-8 d). Results are discussed with respect to the usefulness of this molecular tool for the identification of mealybugs in pest management programs and biosecurity of invasive mealybugs.

Spotted wing drosophila, Drosophila suzukii Matsumura, a native of eastern and southeastern Asia, is a pest of small and stone fruits. First detected in California in 2008, the insect is now found across the Pacific Coast states. Its penchant for attacking healthy, ripening fruit (as opposed to overripe and rotting fruit favored by other so-called “vinegar flies”) makes it a potential economic threat to a host of soft- and thin-skinned fruit crops including cherry, raspberry, blackberry, blueberry, strawberry, peach, plums, pluots, nectarines, juice grape, table grape, and wine grape. Coordinated research projects to determine host preference, seasonal phenology, biology, and management options are taking place among entomologists in Washington, Oregon, and California. A description of the pest and initial findings on its biology, life history, known and expected geographic range, management and monitoring techniques, and economic considerations are presented and discussed.

Crop response to deficit irrigation is an important consideration for establishing irrigation management strategies when water supplies are limited. This study evaluated the response of native spearmint to water deficits applied using overhead sprinklers in eastern Washington, US. Five levels of irrigation were applied ranging from full irrigation (100%) to 5% of weekly averaged full crop water needs. Soil water monitoring with soil water balance was used to estimate soil water deficits for irrigation scheduling and soil water use. Mint oil yields, oil components, dry matter production, and the water-use efficiency of the spearmint were assessed. There was significant reduction in fresh mint hay (harvested biomass) yield with increasing water deficit. However, spearmint oil yields remained generally uniform across irrigation treatments at the first cutting but decreased at the driest plots during the second harvest due to a loss of plant stand. The wet harvest index and water-use efficiency improved significantly for both harvests with increasing water deficit. Hay yield, oil yield, wet harvest index, and water-use efficiency are pooled across sides and replicate blocks to provide trends with changes in maximum evapotranspiration. The three major monoterpenes show changes suggesting less mature oil yields. The study demonstrates the feasibility of sustaining native spearmint yields under managed deficit irrigations for deficits not lower than 0.5 ETc.

Few studies have examined the combined effect of herbicide-induced stress and arthropod herbivory to reduce weed fitness. The purpose of this study was to quantify the effect of arthropod herbivory on the herbicide dose–response of a perennial weed. Fluroxypyr dose–response bioassays using volunteer potato were conducted in the presence and absence of Colorado potato beetle (CPB) herbivory. Logistic model parameter estimates for leaf area, shoot biomass, tuber number, and tuber biomass were often lower with herbivory, compared with no herbivory. Greater variance of parameter estimates within herbivory plots was attributed largely to differential feeding because CPB density was not manipulated in the field. Results from short-season field studies (1,000 growing degree days [GDD] after postemergence [POST] herbicide application) indicated that herbivory had the most effect on potato during a period that coincided with high CPB density and optimal temperatures for CPB development. Season-long bioassays (> 3,100 GDD after POST) revealed that addition of herbivory reduced herbicide use 65 to > 85%, compared with the dose needed to achieve the same reduction in tuber production in the absence of herbivory. Integrated weed management systems targeting volunteer potato are more effective when fluroxypyr applications are made before periods of high herbivory. Moreover, this article describes an experimental approach contributing to optimization of combined effects of arthropod herbivory and reduced herbicide doses.

Forty-eight strawberry (Fragaria ×ananassa Duchesne) or (Fragaria L. sp.) genotypes from the University of California advanced-cycle breeding population were evaluated over 7 years for susceptibility to and tolerance of infestation by two-spotted spider mite (Tetranychus urticae Koch). In pairwise tests, 23 photoperiodically short-day genotypes were compared with the short-day cultivar Chandler, and 23 day-neutral genotypes to the day-neutral cultivar Selva. Feeding by T. urticae resulted in substantial yield reductions regardless of genotype. Yield reduction from feeding by T. urticae averaged 29.9% for short-day and 23% for day-neutral genotypes. Calculation of variance components for day-neutral genotypes determined that none of the variation in yield was explained by the interaction of genotype and T. urticae infestation, whereas 24.4% of the variation in yield for short-day genotypes was explained by the interaction of genotype and T. urticae infestation. Under current strawberry production practices in California there appears to be little potential for breeding direct resistance to T. urticae for day-neutral genotypes. However, some gains in breeding direct T. urticae resistance may be achieved within short-day genotypes. Phenotypic path-coefficient analysis for direct and indirect effects, and simple correlation coefficients of T. urticae feeding determined there were substantial differences between short-day and day-neutral genotypes in their yield responses to T. urticae feeding. For short-day genotypes, the greatest direct effect on yield resulted from T. urticae feeding in June. For day-neutral genotypes, the greatest direct effects resulted from T. urticae feeding in April and May and were probably due to the day-neutral genotype's more complex flowering responses. Several high-yielding cultivars have been developed and released over the 7 years of this study. It appears the new cultivars that were bred for current cultural practices exhibited a consistent plant response for greater yield both in the presence and absence of T. urticae feeding.

ATP-binding cassette (ABC) transporters are a large superfamily of proteins that mediate diverse physiological functions by coupling ATP hydrolysis with substrate transport across lipid membranes. In insects, these proteins play roles in metabolism, development, eye pigmentation, and xenobiotic clearance. While ABC transporters have been extensively studied in vertebrates, less is known concerning this superfamily in insects, particularly hemipteran pests. We used RNA-Seq transcriptome sequencing to identify 65 putative ABC transporter sequences (including 36 full-length sequences) from the eight ABC subfamilies in the western tarnished plant bug (Lygus hesperus), a polyphagous agricultural pest. Phylogenetic analyses revealed clear orthologous relationships with ABC transporters linked to insecticide/xenobiotic clearance and indicated lineage specific expansion of the L. hesperus ABCG and ABCH subfamilies. The transcriptional profile of 13 LhABCs representative of the ABCA, ABCB, ABCC, ABCG, and ABCH subfamilies was examined across L. hesperus development and within sex-specific adult tissues. All of the transcripts were amplified from both reproductively immature and mature adults and all but LhABCA8 were expressed to some degree in eggs. Expression of LhABCA8 was spatially localized to the testis and temporally timed with male reproductive development, suggesting a potential role in sexual maturation and/or spermatozoa protection. Elevated expression of LhABCC5 in Malpighian tubules suggests a possible role in xenobiotic clearance. Our results provide the first transcriptome-wide analysis of ABC transporters in an agriculturally important hemipteran pest and, because ABC transporters are known to be important mediators of insecticidal resistance, will provide the basis for future biochemical and toxicological studies on the role of this protein family in insecticide resistance in Lygus species.

Drosophila suzukii Matsumara, also referred to as the spotted wing drosophila, has recently expanded its global range with significant consequences for its primary host crops: blueberries, blackberries, raspberries, cherries, and strawberries. D. suzukii populations can increase quickly, and their infestation is difficult to predict and prevent. The development of effective tools to detect D. suzukii presence in new areas, to time the beginning of activity within a crop, to track seasonal activity patterns, and to gauge the effectiveness of management efforts has been a key research goal. We compared the efficiency, selectivity, and relationship to fruit infestation of a range of commonly used homemade baits and a synthetic formulated lure across a wide range of environments in 10 locations throughout the United States. Several homemade baits were more efficient than apple cider vinegar, a commonly used standard, and a commercially formulated lure was, in some configurations and environments, comparable with the most effective homemade attractant as well as potentially more selective. All alternative attractants also captured flies between 1 and 2 wk earlier than apple cider vinegar, and detected the presence of D. suzukii prior to the development of fruit infestation. Over half the Drosophila spp. flies captured in traps baited with any of the attractants were not D. suzukii, which may complicate their adoption by nonexpert users. The alternative D. suzukii attractants tested are improvement on apple cider vinegar and may be useful in the development of future synthetic lures.

Water-saving strategies aimed at improving water use efficiency need to be applied in agriculture today to ensure sustainable use of scarce water resources. This article presents results of a 2-year study done at Washington State University's Irrigated Agriculture Research and Extension Center (IAREC) to determine the effect of various water stress levels applied at various times during the growth period to the yield quantity, quality, and production costs of drip-irrigated native spearmint (Mentha spicata L.). The field experiment included four irrigation levels (40, 54, 80, and 100% of ETc) and four stress timings: T1(the irrigation levels were applied throughout the growing season), T2, T3, and T4 where the irrigation levels were applied 21, 14, and 7 days before harvest, respectively. Hay yields decreased with increasing water stress; mean annual hay yield ranged from 47.2 Mg/ha under the driest treatment (40% irrigation level at timing T1) to 61.2 Mg/ha under 100% irrigation level. Mean annual oil yields ranged between 108 and 147 kg/ha among treatments. Fully irrigated plots gave average oil yields of 127 kg/ha. Deficit irrigation thus has potential to give similar or even higher oil yields than those from fully irrigated plots. Water stress did not significantly affect oil quality. The oil concentration (kg of oil per kg of hay) increased with water stress; mean oil concentrations ranged from 0.22% under 100% irrigation level to 0.31% under the driest treatment.Water use efficiency (oil yield per unit volume of water consumed) also increased with increasing water stress, ranging from 0.009 kg/m3 under 100% irrigation level to 0.026 kg=m3 under the driest treatment. Costs of production savings were 2.9, 6.6, and 8.6% per hectare for the 80, 54, and 40% of ETc, respectively, when compared to the full irrigation scenario. Results show that up to 60% irrigation deficit in native spearmint, no matter its timing, can save water, improve water use efficiency, and reduce costs of production while maintaining oil yields and quality similar to those from fully irrigated plants. © 2014 American Society of Civil Engineers.

We tested an immunomarking system that used egg white as marker and enzyme-linked immunosorbent assay as a detection assay to characterize face fly (Musca autumnalis DeGeer) dispersal from cow pats in a pastured beef cattle operation. In microcage assays, adult flies acquired marker after contact with cow pats that were treated with marker and field aged up to 11 d. In arena assays on sprayed full-size cow pats, 77% of eclosed face flies acquired the marker. In a field-marking study, four applications of egg white marker were applied on freshly deposited cow pats over a summer at two peripheral paddocks to a main grazing pasture of ≍50 head of beef cattle. Of the 663 face flies captured, 108 were positive for the egg white marker (16.3%). Of the marked flies, ≍ twofold more male than female flies were captured. Sex-specific dispersal distances were roughly equal up to 450 m, with 11% of female flies dispersing450 m. Dispersal capability of face flies is discussed in relation to efficacy of rotational grazing and other IPM strategies.

Yield of day-neutral strawberries, Fragaria × ananassa Duch (‘Selva’), grown in California were evaluated for 7 yr over a range of twospotted spider mite, Tetranchus urticae Koch, population densities. From 1988 through 1994, acaricide treated and untreated plots of Selva were established each fall in Watsonville, Santa Cruz County, CA. T. urticae population densities were calculated on a per midtier leaflet basis every 2 wk as the average number of motile T. urticae counted on 10 midtier leaflets sampled from each plot. Mite-days were calculated from these counts and summed for monthly intervals by using 15 March and 30 August as starting and ending dates, respectively. These calculations provide a standard index of T. urticae feeding pressure on strawberry plants among and within years. Yield loss resulting from T. urticae feeding in untreated plots versus plots treated with acaricides averaged 25%. T. urticae feeding had little or no effect on fruit size but caused a significant reduction in the number of berries produced per plant. The later T. urticae were first detected in winter or spring, the less yield was reduced during the peak fruiting months of June and July. Maximum T. urticae abundance was negatively associated with yield, and greater mite-day accumulations were associated with yield decline. Regression analysis indicated that the 0% yield reduction threshold averaged 30 cumulative mite days during any monthly period. This implies that detectible yield reduction caused by mite feeding occurs at population densities > 1 T. urticae per leaflet. However, late winter and early spring mite feeding resulted in greater yield reductions than mite feeding at equivalent levels of infestation in late spring and summer. Yield reduction resulting from mite feeding is cumulative at relatively low population levels throughout spring and damage resulting from mite feeding plateaus during summer.

Strawberry ( Fragaria x ananassa ) developmental physiology is affected by temperature and photoperiod. Supplemental cold storage treatments of daughter plants of the reproductively day-neutral ‘Selva’, between their harvest from high-elevation propagation nurseries and fall transplant into production fields, stimulated vegetative vigor. In a 3-yr study, the increased vegetative vigor resulting from pretransplant supplemental cold storage treatments reduced susceptibility to infestation by and abundance of twospotted spider mites, Tetranychus urticae Koch, during the subsequent fruit production season. Harvest date of daughter plants had an effect on the size of T urticae populations in the following production season if the plants failed to receive adequate vernalization in the field during winter. Medium versus large daughter-crown diameter at transplant produced no significant differences in susceptibility to spider mite infestation, or in the degree of vegetative vigor or yield. Proper manipulation of daughter-plant chilling treatment may enable strawberry producers to decrease plant susceptibility to T urticae infestation, produce optimum-sized plants, and maximize yield.

Knockdown resistance (kdr) has been identified as a main mechanism against pyrethroid insecticides in many arthropod pests including in the onion thrips, Thrips tabaci. To characterize and identify pyrethroid-resistance in onion thrips in Washington state, we conducted insecticide bioassays and sequenced a region of the voltage gated sodium channel gene from several different T. tabaci populations.Field collected Thrips tabaci were found to have large variations in resistance to the pyrethroid insecticide lambda-cyhalothrin. We identified two single nucleotide substitutions in our analysis of a partial sequence of the T. tabaci voltage-gated sodium channel gene. One mutation resulted in the non-synonymous substitution of methionine with leucine (M918L), which is well known to be responsible for super knockdown resistance in some pest species. Another non-synonymous substitution, a valine (GTT) to alanine (GCT) replacement at amino acid 1010 (V1010A) was identified in our study and was associated with lambda-cyhalothrin resistance.We have characterized a known kdr mutation and identified a novel mutation in the voltage-gated sodium channel gene of Thrips tabaci associated with resistance to lambda-cyhalothrin. This gene region and these mutations are expected to be useful in the development of a diagnostic test to detect kdr resistance in many onion thrips populations.

International audience; Soils in beds of commercially managed Nomia melanderi were manipulated with surface treatments to reduce or increase temperatures at nest depths of 20 cm. Modifying soil temperatures affected pupation rate and emergence date of N. melanderi. In 2010, white chalk dust delayed peak bee emergence by one week, and clear plastic mulch initiated peak emergence one week earlier, significantly increasing overall bee emergence compared to uncovered areas. In 2011, treatments included white chalk dust and plastic agricultural sheets including clear, red, black, white-on-black, blue, and brown. In 2011, clear plastic sheeting initiated early emergence while white chalk dust and white-on-black plastic plots delayed emergence. Expediting or postponing N. melanderi emergence could potentially allow alfalfa seed producers to extend the bees’ foraging season over a greater time period, subsequently increasing pollination, seed set, and economic returns.

Within the United States, Washington is the number one producer of ‘Concord’ grapes and the number two producer of wine grapes. Previous studies in wine grapes revealed the presence of twelve different viruses in Washington vineyards. Despite what is known about viruses in wine grapes in Washington, virtually no studies have focused on viruses in Concord vineyards. To further understand the epidemiology of viruses in Washington State, a survey of Concord grapes was conducted in 2010 and 2011. Five hundred Concord vines were sampled and tested for the presence of virus, and five different viruses were found among 92 virus-positive samples. The most common virus found was Grapevine leafroll-associated virus 3 (51 samples), followed by Grapevine fanleaf virus (24 samples), Grapevine leafroll-associated virus 4 (nine samples), Grapevine leafroll-associated virus 2 (four samples), and Grapevine leafroll-associated virus 9 (four samples). The presence of viruses in Concord vineyards is of great concern for growers due to likely movement of virus diseases from Concord grapes to wine grapes that might result in economic losses to the grape industry. Accepted for publication 19 May 2012. Published 5 August 2013.

Plant physiological status determines translaminar movement of avermectin B 1 in strawberry leaves, and the resulting noncontact residual kill of twospotted spider mite, Tetranychus urticae Koch. Significant T urticae mortality was obtained upon contact with avermectin B 1 with and without the addition of dormant oil, and with propargite. Noncontact residual kill of T. urticae by avermectin B 1 was greater on fruiting summer-type plants than on plants in winter semidormancy. When avermectin B 1 was applied only to the top surface of leaves, addition of dormant oil enhanced T urticae mortality on lower leaf surfaces of plants in winter semidormancy. T. urticae mortality was not affected by the addition of oil when plants were in either a spring-type vegetative growth state or a summer-type sexual state. The results of this study suggest an explanation for inconsistencies observed in field applications of avermectin B 1 for control of T. urticae.

Contracted commercial beekeeping operations provide an essential pollination service to many agricultural systems worldwide. Increased use of genetically engineered crops in agriculture has raised concerns over pollinator-mediated gene flow between transgenic and conventional agricultural varieties. This study evaluated whether contracted migratory beekeeping practices influence transgenic pollen flow among spatially isolated alfalfa fields. Twelve honey bee ( Apis mellifera L.) colonies were permitted to forage on transgenic alfalfa blossoms for 1 wk in Touchet, WA. The hives were then transported 112 km to caged conventional alfalfa plots following one and two nights of isolation (8 and 32 h, respectively) from the transgenic source. Alfalfa seed harvested from the conventional plots was assessed for the presence of the transgene using a new seedling germination assay. We found that 8 h of isolation from a transgenic alfalfa source virtually eliminated the incidence of cross-pollination between the two varieties.

Lygus bug (Lygus hesperus) feeding causes small strawberry size and weight, but the most serious damage is a deformation of the fruit called “cat-facing.” Over two growing seasons, three grower-designed vacuum machines were evaluated for season-long control of Lygus bugs in production strawberry (var. ‘Selva’) fields on the coast. The Lygus bug control in fields vacuumed weekly and twice-weekly was compared to that in fields treated with malathion insecticide or an unregistered pesticide, bifenthrin. All vacuum machines significantly reduced Lygus bug damage when compared to the untreated control. However, the damage in plots treated only with the vacuum machines was high enough to be considered economically unacceptable.

Onion thrips are the key pest for dry bulb onion production in Washington State. The trial was initiated on June 8, 2012, in Pasco, WA, in a yellow onion field under drip irrigation. Plots were 7.33 feet wide and 25 feet long in an RCB design with four replicates. Applications were made with a …

Face flies, Musca autumnalis De Geer (Diptera: Muscidae), and houseflies, Musca domestica L. (Diptera: Muscidae), have a significant impact on livestock and dairy production throughout North America. Pyrethroid insecticide efficacy can be affected by exposure to direct sunlight, and the rate of photodegradation is substrate and formulation dependent. Insecticide-treated netting (ITN) is finding new applications in crop and livestock production systems. A baseline study using long-duration no-choice assays has been carried out to gauge the effectiveness of ITN treated with β-cyfluthrin, λ-cyhalothrin and bifenthrin on face flies and houseflies.After 12 weeks in direct sunlight, ITN treated with β-cyfluthrin was still highly insecticidal to face flies and houseflies, producing 100% mortality in petri dish assays. However, sunlight reduced the insecticidal activity of λ-cyhalothrin, with 3% of face flies and 50% of houseflies surviving after exposure to ITN that had been deployed for 10 weeks. Insecticidal activity was greatly reduced on bifenthrin-treated netting, with 20% of face flies and 50% of houseflies surviving in assays with netting deployed for only 3 weeks.With careful choice of the pyrethroid applied, treated netting could be an important component of livestock integrated pest management programs focused on sustainable practices.

Three representative suction machines were evaluated for control of Lygus hesperus (Knight) on strawberries for two growing seasons in production fields. Weekly and twice-weekly vacuum passes through a field were compared with bifenthrin applications in 1989. Weekly and twice-weekly vacuum passes were compared with bifenthrin (0.11 kg [AI]/ha) and malathion (1.26 kg [AI]/ha) sprays applied using a degree-day phenology model and with a combination of malathion and weekly vacuuming in 1990. All three machines reduced damage caused by L. hesperus when compared with the untreated control. The three-bed vacuum is the largest machine, with the highest air flow, tested, resulting in a significant reduction in damage compared with the untreated. The smaller one-bed and two-bed machines did not decrease the numbers of nymphs or damage. However, the treatments in which vacuum machines were used exclusively had damage that was not economically acceptable. Twice-weekly vacuum passes did not improve L. hesperus control compared with weekly vacuum passes. Weekly vacuum passes combined with malathion sprays were no better than either treatment alone. Bifenthrin provided effective control but resulted in spider mite (244.6 mites per leaflet) population increases after 3-4 wk. Weekly vacuum treatments provided control of L. hesperus equal to that of one or two applications of malathion.

BACKGROUND: Drosophila suzukii was first found in Oregon in August 2009. The threat of this pest to regional small and stone fruit production industries led to investigations on its overwintering capabilities in fruit-growing regions in the Pacific Northwest. Knowledge of its cold tolerance will help in the development of computer models to forecast seasonal population growth and decline. RESULTS: Of 1500 adults or pupae, 22 (1.4%) individuals survived the 84 day experimental chilling period. Most (86%) of the survivors were subjected to 10 ◦ C temperature treatments. Survival decreased significantly at lower temperature treatments. Freezingtemporarilyincreasedthemortalityratebutdidnotsignificantlyaffectoverallmortalityoverthetrialperiod.Fliesthat emerged from pupae are estimated to survive for up to 103‐105 days at 10 ◦ C and for shorter periods at lower temperatures. Field trapping in five fruit production areas has demonstrated overwintering survival in California and Oregon, but lower survival is predicted in Eastern Washington and Michigan. CONCLUSION: The experiments reported here indicate that long-term survival of D. suzukii is unlikely at temperatures below 10 ◦ C. Field data from five climatic regions indicated extended low initial D. suzukii field presence in 2010 in all regions except California, where field presence was recorded earlier. c � 2011 Society of Chemical Industry

Several suction sampling devices were compared with a beating tray and a whole-plant sample for determining population abundance of Lygus hesperus (Knight) as well as some beneficial predatory arthropods (Geocoris spp., Hemerobius spp., Chrysopa camea (Stephens), Orius tristicolor (White), and spiders) in California strawberry fields. The Allen-vac (A-vac) sampler best approximated the whole-plant sample for L. hesperus and beneficials except spiders. The beating tray provided the most consistent though lower estimates, but could provide a useful estimate of L. hesperus and beneficial arthropod abundance in an integrated pest management monitoring program. The D-vac provided a slightly lower estimate of L. hesperus density than did the A-vac samples or beating-tray samples at a greater cost in sampling time. For each regression of relative technique against the corresponding whole-plant estimate, the intercept was not significantly different from 0. Taylor’s power law was used to develop variance-mean models for each sampling type tested.

The presence of Multicolored Asian Lady Beetles (MALB) in grape juice is increasingly problematic. The overall objective of this study was to determine the specific sensory impacts of MALB on Concord and Niagara grape juice. The aroma threshold for MALB-taint in both juices was determined and expressed as the best estimate threshold (BET). The aroma BET for MALB-taint in Concord grape juice was 1.8 and 0.65 MALB/L Niagara grape juice. The specific sensory attributes of the grape juices influenced by the presence of MALB were then described. In Concord grape juice, trained panelists (n = 9) found significant increases in vegetal aroma and earthy flavor as MALB concentration increased from 0.45 to 7.2 MALB/L. In Niagara grape juice, with increasing MALB concentration, trained panelists (n = 8) indicated significant decreases in honey and sweetness with corresponding increases in sourness, astringency, and vegetal and earthy aromas and flavors (P < 0.05). For both aroma and flavor, consumer rejection studies were performed using paired preference comparisons of control juice to MALB-tainted grape juice. For Concord grape juice, consumers (n = 60) rejected the aroma of MALB-tainted juice at 1.8 MALB/L and the taste/flavor of the MALB-tainted juice at 3.6 MALB/L. For Niagara juice, consumers rejected the aroma of the juice at 3.6 MALB/L. This study demonstrated the presence of MALB negatively impacts the sensory properties of Concord and Niagara grape juice. Grape juice processors may use this research for quality control measures and for establishing tolerance limits. Practical Application: The Multicolored Asian Ladybeetle (MALB), initially used for biocontrol, has been shown in previous literature to impact the sensory properties of wines. The presence of MALB in grape juice is now becoming problematic; however, there is little research describing the specific sensory impacts of MALB on grape juice. This study examined the sensory impact of MALB on both Concord and Niagara grape juice. While the threshold and trained panel evaluations from this study provide valuable sensory profile information, grape juice processors may be particularly interested in the consumer rejection of MALB-tainted grape juice as they can use this research for quality control measures and for establishing tolerance limits.

Barrier application for cutworm control in vineyards requires an efficient target recognition system and a rapid and precisely sprayer control system to ensure an adequate coverage on grape trunks. This research was to develop a trailer based targeted sprayer system. This automated targeted sprayer system consists of a scanning laser based trunk detection system and a multi-nozzle sprayer control system installed on a modified trailer sprayer. The target recognition system is operated by customized software installed on a laptop PC. The sprayer system consists of two arrays, one on each side, with three nozzles connected to solenoids wired to a CAN bus control system. Each nozzle can be controlled independently allowing for various up to 7 application rates. A trunk size compensation function was developed to improve the accuracy of the target recognition system. Tests were performed to evaluate the system’s trunk detection accuracy in both a simulative vineyard and a real vineyard. Results indicated that the trunk size compensation function limited the root-mean-square error of the trunk radius detection to no more than 5.5 mm at travel speed up to 1.34 ms-1.

Our major objective was to develop an autonomous application system for targeted pest control designed specifically to improve barrier applications for cutworm control in grapes as a model for other pest management in other crops. The developed system consisted of three sub-systems: a sensor system for target recognition, a sprayer system with controllable valves, and an automated vehicle carrying the sensors and sprayer. Two laser sensors detected vine trunks and provided their position and size measurements. A micro controller on the sprayer system operated the valve opening and closing triggered to precisely apply a pesticide in a small band on the vine trunk in quantities that created an effective barrier for the cutworm while reducing the total amount of pesticide applied. A small electric utility vehicle was used as a platform, with several modifications made to the vehicle’s steering and throttle to implement auto-steering and speed control functions. These vehicle automation modifications would improve spraying accuracy and lower operator fatigue. The automated sprayer system prototype was complete and tested at a vineyard for validating its trunk detection accuracy.