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This study investigates the infestation dynamics of Panonychus ulmi McGregor 1916 and its associated predators in Malus domestica borkh orchards across three towns in Morocco: Midelt, Ait Sebaa, and Imouzzer-Kender, situated in the Fez-Meknes and Draa-Tafilalt regions. Ait Sebaa (Fez-Meknes region), characterized by high temperatures and a lower altitude, exhibited a substantial increase in P. ulmi and its predators. In contrast, Midelt (Draa-Tafilalt region), with the highest altitude, demonstrated lower mite counts. Imouzzer-Kender (Fez-Meknes region), at an intermediate altitude, showed moderate mite levels. Detailed findings reveal a positive correlation between P. ulmi and temperature, as well as with phytoseiid mites. Conversely, a negative correlation exists between P. ulmi and altitude. Additionally, a positive correlation between phytoseiid mites and temperature is identified. Overall, this study provides valuable information on the ecological interactions between mites, temperature, altitude and humidity in distinct Moroccan regions, highlighting the need to take regional specificities into account in pest management strategies. [ABSTRACT FROM AUTHOR]

Predictive studies project the geographic distribution of species and can be used to infer climatic niches. However, only a few studies have been conducted on mites. This approach helps map areas with potential for the occurrence of endemic, threatened, or potentially invasive species. Panonychus ulmi (Tetranychidae) is of global economic importance, commonly associated with apple orchards and grapevines. Potential distribution modeling is used to predict areas with environmental suitability for the distribution of a species and/or group. Considering that predictive models on national or regional scales present better data reliability, the present study aimed to analyze the distribution of P. ulmi in Brazil through bioclimatic inferences. The presence of species, bioclimatic variables, and MaxEnt algorithm were used to define a predictive model. The median performance rate of the model was 0.992, indicating its robustness. The variable that made the greatest contribution to the model was the average temperature of the coldest quarter (Bio11). The predictive model of the ecological niche indicated that the southern region of Brazil is environmentally favorable for the adaptation of this mite. The data obtained helped us understand the geographical distribution of P. ulmi in Brazil, and climatically suitable areas for its occurrence were inferred. We believe that this tool can offer indirect assistance to the agricultural sector, especially the producers of apples and grapes in Brazil regarding the presence of P. ulmi.

The objective of this research was to study potential pests of Japanese quince (Chaenomeles japonica) plantations in Latvia. Studies were carried out in eight plantations during 2017-2019. Major pests that would regularly cause significant yield losses for this plant were not observed. Black-veined white (Aporia crataegi) was considered a local pest, mass outbreaks of which can occur in individual plantations and cause significant losses of plant foliage. Four species were considered minor pests: garden chafer (Phyllopertha horticola), yellow-banded weevil (Chlorophanus viridis), silver-green weevil (Phyllobius argentatus) and copse snail (Arianta arbustorum); they are also pests of plant foliage. The European red spider mite (Panonychus ulmi) was not considered as a pest of Japanese quince. A small population was observed in summers only in one plantation, which was located next to a heavily infested orchard. Overwintering eggs were not found on the plants in any year, and we concluded that the species was an accidental immigrant in this plantation. No aphid (Aphididae) colonies were observed on the quince plants. Monitoring and evaluation of potential harmfulness of four tortrix moths - large fruit-tree tortrix (Archips podana), rose tortrix (Archips rosana), codling moth (Cydia pomonella) and holly tortrix (Rhopobota naevana) - was done. It was concluded that rose tortrix is a minor fruit pest, but the other three species were not yet considered pests of Japanese quince. Significant pests of quince flowers and fruits were not detected in our study. [ABSTRACT FROM AUTHOR]

This study investigates the infestation dynamics of Panonychus ulmi McGregor 1916 and its associated predators in Malus domestica borkh orchards across three towns in Morocco: Midelt, Ait Sebaa, and Imouzzer-Kender, situated in the Fez-Meknes and Draa-Tafilalt regions. Ait Sebaa (Fez-Meknes region), characterized by high temperatures and a lower altitude, exhibited a substantial increase in P. ulmi and its predators. In contrast, Midelt (Draa-Tafilalt region), with the highest altitude, demonstrated lower mite counts. Imouzzer-Kender (Fez-Meknes region), at an intermediate altitude, showed moderate mite levels. Detailed findings reveal a positive correlation between P. ulmi and temperature, as well as with phytoseiid mites. Conversely, a negative correlation exists between P. ulmi and altitude. Additionally, a positive correlation between phytoseiid mites and temperature is identified. Overall, this study provides valuable information on the ecological interactions between mites, temperature, altitude and humidity in distinct Moroccan regions, highlighting the need to take regional specificities into account in pest management strategies.

Simple Summary: Panonychus ulmi is a pest of several agriculturally important crops, including apples. If populations are not controlled, it can cause severe foliar damage in apple that results in lower return bloom and yield loss in following year. Biological mite control of this pest can be achieved in eastern United States apple orchards if growers conserve several species of predatory mites through proper selection and timing of insecticide applications for the main pests such as codling moth which directly damage the fruit. When apple growers occasionally loose biological mite control, they need to rely on effective miticides that also conserve these predatory mite species to maintain sustainable pest mite control. Efficiency of different pesticide chemicals used for the P. ulmi management and their non-target effects on predatory mites conserved for biological mite control in apple orchards are discussed. Panonychus ulmi (Koch) (Acari: Tetranychidae), commonly known as European red mite, is a polyphagous pest of various tree and small fruit crops, including apples. A field study was conducted to evaluate different pesticide options available for the management of P. ulmi, and their impact on the population of non-target predatory mite species complex consisting of Neoseiulus fallacis, Typhlodromus pyri, and Zetzellia mali in apple orchards. Pesticides were applied using a commercial airblast sprayer at the 3–5 mite/leaf recommended economic Integrated Pest Management (IPM) threshold or prophylactically in the spring ignoring IPM practices such as monitoring, reliance on biological control and economic thresholds. Effects on the motile and egg stages of P. ulmi were evaluated as were effects on the populations of predatory mites through frequent leaf counts during the season. We also recorded the subsequent overwintering eggs of P. ulmi from each pesticide treatment. The two prophylactic treatments containing a mixture of zeta-cypermethrin + avermectin B1 + 1% horticultural oil and abamectin + 1% horticultural oil provided effective control of P. ulmi population throughout the season without reducing predatory mite populations. In contrast, eight treatments applied at the recommended economic threshold of 3–5 mites/leaf were not effective in suppressing P. ulmi populations and most reduced predatory mites. Etoxazole had significantly higher number of overwintering P. ulmi eggs compared to all other treatments. [ABSTRACT FROM AUTHOR]

Field experiments were carried out to evaluate the bioefficacy and safety to the natural enemies of horticulture mineral oil veedol tree spray oil and standard check MAK All Season HMO against San Jose scale (SJS) Quadraspidiotus perniciosus (Comstock) and European red mite (ERM) Panonychus ulmi (Koch) at different concentrations .The locations were Chandpora (District Srinagar) and Mirgund (District Baramulla) of J&K during 2019 and 2020.All the treatments were significantly superior as compared to untreated control. The highest cumulative mean mortality of SJS was (57.55 and 54.50 percent) and ERM (60.46 and 55.54 percent) at the concentration of 2.5 percent both for both Chandpora and Mirgund during dormant 2019-20. The highest cumulative mean mortality of SJS was (54.89 and 62.12 percent) and ERM (64.48 and 68.06 percent) at the concentration of 1.25 percent for Chandpora and Mirgund during summer 2019-20. Maximum cumulative mortality of Coccinellids was recorded (22.46 and 20.17 percent) @ 1.25 percent by veedol tree spray oil and MAK all season HMO at Chandpora and Mirgund respectively. No phytotoxicity symptoms viz., leaf injury, yellowing, wilting, necrosis, hyponasty and epinasty were observed with veedol tree spray oil. Maximum yield of 4.40 and 4.50 boxes/tree was attained with MAK (standard check) @1.25 percent. [ABSTRACT FROM AUTHOR]

Panonychus ulmi (Koch) (Acari: Tetranychidae), commonly known as European red mite, is a polyphagous pest of various tree and small fruit crops, including apples. A field study was conducted to evaluate different pesticide options available for the management of P. ulmi, and their impact on the population of non-target predatory mite species complex consisting of Neoseiulus fallacis, Typhlodromus pyri, and Zetzellia mali in apple orchards. Pesticides were applied using a commercial airblast sprayer at the 3–5 mite/leaf recommended economic Integrated Pest Management (IPM) threshold or prophylactically in the spring ignoring IPM practices such as monitoring, reliance on biological control and economic thresholds. Effects on the motile and egg stages of P. ulmi were evaluated as were effects on the populations of predatory mites through frequent leaf counts during the season. We also recorded the subsequent overwintering eggs of P. ulmi from each pesticide treatment. The two prophylactic treatments containing a mixture of zeta-cypermethrin + avermectin B1 + 1% horticultural oil and abamectin + 1% horticultural oil provided effective control of P. ulmi population throughout the season without reducing predatory mite populations. In contrast, eight treatments applied at the recommended economic threshold of 3–5 mites/leaf were not effective in suppressing P. ulmi populations and most reduced predatory mites. Etoxazole had significantly higher number of overwintering P. ulmi eggs compared to all other treatments.

In this study, the dose-response relationship between abamectin and mortality of larval and adult forms of Panonychus ulmi (Koch) was established. Abamectin was investigated at a dilution series of 1/1, 1/1.15, 1/1.35, 1/1.6, 1/2, 1/2.55, 1/4, 1/8 and 1/16 of its field recommended concentration, in order to calculate the ECi - values. Results showed that the lowest ECi - values were observed on larvae, which showed high sensitivity to abamectin than adults. Both statistical models led to satisfactory findings and the linear model was ranked as the best model for describing the dose-response relationship. This research highlighted the importance of toxicity risk assessments to obtain a more accurate estimation of the compatibility of abamectin in the integrated pest management (IPM) programs. [ABSTRACT FROM AUTHOR]

Knowledge about phytoseiid species associated with vines is a preliminary step in the development and implementation of integrated management strategies against phytophagous mites such as Panonychus ulmi. The aim of this study was to perform a comparative survey of phytoseiids present in abandoned, organically managed, and conventionally managed vineyards, as well as to compare ecological indices in these production systems. Samplings were conducted between July and September 2017 in vineyards situated in the Subregions of Lima and Cávado, the Vinho Verde region. A total of 50 leaves/vineyard were collected from 12 vineyards, kept in containers at low temperature and taken to Escola Superior Agrária-Instituto Politécnico Viana do Castelo to be screened under a stereoscope microscope. A total of 3.153 phytoseiid mites were sampled, belonging to eight species distributed across the vineyards analyzed. The most common species were Typhlodromus (Typhlodromus. pyri (45.7%), Kampimodromus aberrans (39%), and Phytoseius macropilis (8.7%). Higher richness occurred in abandoned vineyards, with seven species, and the most abundant were K. aberrans (46.5%) and T. (T.. pyri (28.9%). Only two predatory species were present (in similar proportions) in organically managed vineyards, T. (T.. pyri and K. aberrans, while T. (T.. pyri predominated in conventionally managed vineyards (93.8%). Kampimodromus aberrans. P. macropilis, and T. (T.. pyri were eudominant in abandoned vineyards while K. aberrans and T. (T.. pyri were eudominant in organic vineyards. Typhlodromus (T.. pyri was eudominant and T. (T.. exhilaratus was dominant in conventionally managed vineyards. Therefore, we might conclude that phytoseiid abundance significantly differs among vineyard management types, with higher ecological indices in abandoned vineyards, and lower indices in conventional managed vineyards in the northern region of Portugal. [ABSTRACT FROM AUTHOR]

The development of Panonychus ulmi feeding on apple leaves has been widely studied, but nothing is known about its development on grapevine leaves. This study aimed to gather biological information on P. ulmi based on its life table on leaves of Cabernet Sauvignon (CS) and Pinot Noir (PN) grapevine cultivars, and check the oviposition rate of populations on apple and grapevines. The development of P. ulmi started with 30 eggs on CS and 30 eggs on PN, and oviposition tests were performed with four combinations (C1: ♂ Apple X ♀ Apple; C2: ♂ Grapevine X ♀ Grapevine; C3: ♀ Apple Isolated; and C4: ♀ Grapevine Isolated). This study was carried out at 25 ± 3 °C temperature, 14 h of photoperiod, and 70 ± 5% relative humidity. There was no significant difference (P > 0.05) in the grapevine cultivars studied, except for larval and egg-adult period of females and males. A significant difference (P ≤ 0.05) was observed for preoviposition and adult longevity. Life table parameters on CS were R0 = 7.88, T = 17.78 days, TD = 5.97 days, rm = 0.12, λ = 1.12; and on PN they were R0 = 5.20, T = 16.45 days, TD = 6.91 days, rm = 0.10, and λ = 1.11. Females of cross C1 laid an average of 3.44 ± 1.6 eggs daily, in C2 they laid 2.70 ± 1.76 eggs, in C3 they laid 4.19 ± 1.88 eggs, and females of C4 laid 3.6 ± 1.19 eggs. Data in our study allowed us to conclude that the development of P. ulmi is similar on the two grapevine cultivars studied. However, when its performance is compared to apples, reproductive potential on vineyards is lower. [ABSTRACT FROM AUTHOR]

In this paper, the coefficients were obtained for the prey-predator models Lotka-Volterra with competition and prey-predator of the Holling II type considering the mite system P. ulmi and its predator N. californicus. Using the SDRE control for both the control and a state observer, it was possible to solve the optimal control problem for quadratic functional non-linear systems. The computational simulations demonstrate the efficiency of both the control strategy and stabilize the system at the desired level below that considered critical as the state observer proposal. [ABSTRACT FROM AUTHOR]

European red mite (ERM), Panonychus ulmi (Koch) is a major pest of fruit crops (apple and almond) in Kashmir Valley, India. Investigations were carried out at ICAR-Central Institute of Temperate Horticulture, Srinagar, Jammuand Kashmir to study the population dynamics, biology and efficacy of acaricides against P. ulmi on almond and apple. In both the crops highest population (31.56 and 6.46 mites/leaf), respectively, was observed in the 29th standard week (SW) and significantly correlated with the temperature. Biology of ERM was also studied on almond: eggs hatched in 6.50 ± 0.29 days; larval development took 2.00 ± 0.00 days; protonymphal and deutonymphal stages lasted for 1.75±0.25 days each. Longevity of adult males and females was 4.25 ± 0.25 and 8.25 ± 0.48 days, respectively. The efficacies of some of the acaricides were evaluated against ERM on almond. Among these, fenazaquin 10 EC (0.004 %) was found to be excellent with 94.92 % mortality of ERM on almond. [ABSTRACT FROM AUTHOR]

Studies to study the annual cycle of development and the number of generations of the red fruit mite was continued until the middle of September, since after this period no development was observed in the laid eggs. On the basis of the conducted studies, it was found that the duration of development of the red fruit mite generation varies with temperature and relative humidity, with a combination of high temperature and high humidity accelerating development, while high humidity and low temperature do not accelerate development. At high temperature and low humidity, the mites die. In northeastern Azerbaijan, the red fruit mite on vegetable crops and wild grasses multiplies in seven generations during the growing season. [ABSTRACT FROM AUTHOR]

Over the past few decades, the hazards associated with the extensive use of organictin compounds have become an issue of extreme concern, while at present the effects of these substances on amphibians remain poorly understood. In the present study, we chose azocyclotin, one of common use acaricides in China. We focused on sexual development and steroidogenesis disrupting effects of azocyclotin in the Xenopus laevis . Tadpoles were exposed to azocyclotin (0.05 and 0.5 μg/L) for long-term (4 months) study. Results showed that exposure to azocyclotin caused developmental toxicity, including decreased survival, body weight, body length, gonadosomatic index, hepatosomatic index and female phenotype. At the same time, statistical increase in mean age at completion of metamorphosis was observed in azocyclotin treatments in comparison with control group. Furthermore, hormone concentrations, and steroidogenesis genes expression of adult frog were further evaluated in 28 days exposure. Results demonstrated that the key regulating hormones, e.g. testosterone and pregnenolone, were significantly upregulated. The expression levels of selected steroidogenic genes were also significantly altered. Our study demonstrated that azocyclotin could delay the metamorphosis and disrupt the gonadal differentiation of X. laevis. Steroidogenesis and the expression of genes involved in the hypothalamus-pituitary-gonadal-liver axis in frogs were disrupted after azocyclotin exposure. Azocyclotin showed both androgenic and antiestrogenic activity for X. laevis . Those findings emphasized the influence of azocyclotin on non-target species in the context of ecotoxicological risk assessment. [ABSTRACT FROM AUTHOR]

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.

Neoseiulus fallacis (Garman) (Acari: Phytoseiidae) is an efficient predator of the European red mite (ERM) (Panonychus ulmi (Koch); Acari: Tetranychidae) in Michigan, United States of America apple orchards and an important part of integrated pest management. Four reduced-risk insecticides (acetamiprid, spinetoram, chlorantraniliprole, and novaluron) and two conventional insecticides (esfenvalerate and carbaryl) were tested against N. fallacis for topical toxicity effects. Bioassays using a Potter spray tower were conducted to measure the topical toxicity of compounds when applied at field rate concentrations to N. fallacis. Lethal time was measured for adult N. fallacis at 4, 24, 48, 72, and 96 hours after treatment. Carbaryl and esfenvalerate showed the highest levels of toxicity to adult N. fallacis with shortest lethal time values (LT50) whereas the reduced risk insecticides novaluron, acetamiprid, spinetoram, and chlorantraniliprole were nontoxic. This study provides important information to apple growers regarding direct lethal effect of insecticides on predator mites and its implications to integrated mite management. [ABSTRACT FROM AUTHOR]

To understand the influence of four mulberry varieties on the development and reproduction of the European red spider mite,Panonychus ulmi(Koch) (Prostigmata: Tetranychidae), age-stage two-sex life tables ofP. ulmion Goshoerami, KNG, Chinese white and Rokokuyaso varieties were constructed under ambient laboratory conditions during summer season of the year with an average temperature of 26.22 ± 2.23 °C, relative humidity of 70 ± 5% and photoperiod of 14:10 h (L: D).Panonychus ulmideveloped comparatively better on KNG and Goshoerami varieties than the other two varieties, as indicated by high fecundity (45.05 ± 1.89 and 41.23 ± 1.66 eggs female−1, respectively) and intrinsic rate of increase (0.165 ± 0.01 and 0.168 ± 0.03 day−1, respectively). Lowest intrinsic rate of increase (r) was observed on Chinese white and Rokokuyaso (0.055 ± 0.03 and 0.057 ± 0.10 day−1, respectively). Total development time of immature females was shortest on KNG than on the other varieties. Immature survival was significantly higher on KNG and Goshoerami varieties (76.76 ± 7.59 and 72.96 ± 8.21%, respectively) and was lower on Chinese white and Rokokuyaso (46.76 ± 9.00 and 43.32 ± 8.71%, respectively). Based on all the above parameters, KNG and Goshoerami were found as most suitable varieties forP. ulmithan Chinese white and Rokokuyaso. [ABSTRACT FROM PUBLISHER]

Susceptibility of Panonychus ulmi Koch populations collected from apple orchards in Isparta province was studied against etoxazole, spirodiclofen and hexythiazox, and their detoxification enzyme (esterase, glutathione-S-transferase (GST), monooxygenaz cytochrome P450 (P450) and acetylcholinesterase (AChE)) levels were determined. For this purpose, 13 P. ulmi populations were collected from Isparta province and its districts during summer periods of 2012-2013. Acaricides were applied to mites by spray tower-leaf bioassay method. The data were analyzed by the program POLO PC and LC50 values were calculated. The resistance ratios are calculated by comparing LC50 values of field populations with LC50 values of the susceptible population. The resistance ratios in P. ulmi populations ranged from <1 to 1.95-fold for spirodiclofen, <1 to 2.36-fold for hexythiazox, and <1-7.30-fold for etoxazole. In all population, detoxification enzymes levels were examined biochemically with different substrates. The levels of detoxification enzymes are changed according to populations. [ABSTRACT FROM AUTHOR]

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Efficacy of three acaricides (Ortus 5% EC, Milbeknock 1% EC and Cascade 10% DC) and predatory insect; Chrysoperla carnea Stephens was evaluated on the European red mite Panonychus ulmi Koch (Acari: Tetranychidae) movable stages infested apple orchards during the two successive seasons; 2012 and 2013 at Darawa village, Ashmon, Menoufia governorate, as well as determining the biochemical changes in the treated insects. The results show that, The highest reduction percentages of P. ulmi movable stages during 2012 and 2013 seasons were recorded with Ortus followed by Milbecknok then the predatory insect; C. carnea, while the lowest reduction percentages were recorded with Cascade. The effect of the two acaricides Ortus and Milbecknok (the highest toxic acaricides) on the major biochemical components of P. ulmi adult females showed that, the acaricide Ortus achieved high effects on the total lipids content and the two enzymes Acetylcholinesterase (AchE) and Glutathione-S-transferase (GST). The acaricide Milbecknok recorded high effects on the total lipids and carbohydrates contents and lipase, trehalase, amylase, AchE and GST enzymes. The two acaricides Ortus and Milbecknok are effective in controlling European red mite on apple trees and this can be attributed to abnormal changes of the major biochemical components in the treated mites. The predatory insect; C. carnea has efficient predation against P. ulmi and resulting increasing in the reduction of mite populations. (Ortus 5% EC, يهدف هذا البحث إلي تقييم ثلاثة أنواع من المبيدات الأكاروسية وأحد المفترسات الحشرية (أسد المن) Milbeknock 1% EC and Cascade 10% DC) (Panonychus ulmi علي الأطوار المتحركة للعنكبوت الأحمر الأوربي Chrysoperla carnea الذي يصيب أشجار التفاح خلال موسمي ٢٠١٢ و ٢٠١٣ في قرية Koch (Acari: Tetranychidae) داراوة مركز أشمون محافظة المنوفية وكذلك تقدير التغييرات الكيميائية الحيوية للحشرات المعاملة. أوضحت النتائج أن أعلي نسب إنخفاض في تعداد الأطوار المتحركة للعنكبوت الأحمر الأوربي أثناء C. ثم المفترس الحشري Milbecknok يليه مبيد Ortus موسمي ٢٠١٢ و ٢٠١٣ س جلت مع مبيد Cascade بينما أقل نسب إنخفاض س جلت مع مبيد carnea. علي التغييرات في (Ortus and Milbeknock) أظهرت نتائج المبيدات الأعلي سمةي أحدث تغيرا كبيرا في Ortus المكونات الكيميائية الحيوية لإناث العنكبوت الأحمر الأوربي، أن مبيد .Acetylcholinesterase and Glutathione-S-transferase محتوي اللبيدات الكلية والأنزيمين سجل تأثير ا عاليا علي كل من محتوي اللبيدات والكربوهبدرات الكلية Milbecknok بينما مبيد lipase, trehalase, amylase, Acetylcholinesterase and Glutathione-وكذلك الإنزيمات التالية S-transferase. نستخلص من النتائج السابقة أن نوعين من الثلاثة أنواع من المبيدات الأكاروسية لهما تأثير فعال في مكافحة العنكبوت الأحمر الأوربي علي أشجار التفاح وأن تفسير هذا يمكن إرجاعه إلي التغيرات الغير الطبيعية الحادثة في معظم المكونات الكيميائية الحيوية للحشرة. أيضا مفترس ذو كفاءة إفتراسية عالية ضد العنكبوت الأحمر الأوربي وينتج عن ذلك زيادة C. Carnea الحشرات في إنخفاض تعداد العنكبوت. [ABSTRACT FROM AUTHOR]

Background: The European red mite, Panonychus ulmi, is among the most important mite pests in fruit orchards, where it is controlled primarily by acaricide application. However, the species rapidly develops pesticide resistance, and the elucidation of resistance mechanisms for P. ulmi has not kept pace with insects or with the closely related spider mite Tetranychus urticae. The main reason for this lack of knowledge has been the absence of genomic resources needed to investigate the molecular biology of resistance mechanisms. Results: Here, we provide a comprehensive strand-specific RNA-seq based transcriptome resource for P. ulmi derived from strains susceptible and resistant to the widely used acaricide spirodiclofen. From a de novo assembly of the P. ulmi transcriptome, we manually annotated detoxification enzyme families, target-sites of commonly used acaricides, and horizontally transferred genes implicated in plant-mite interactions and pesticide resistance. In a comparative analysis that incorporated sequences available for Panonychus citri, T. urticae, and insects, we identified radiations for detoxification gene families following the divergence of Panonychus and Tetranychus genera. Finally, we used the replicated RNA-seq data from the spirodiclofen susceptible and resistant strains to describe gene expression changes associated with resistance. A cytochrome P450 monooxygenase, as well as multiple carboxylcholinesterases, were differentially expressed between the susceptible and resistant strains, and provide a molecular entry point for understanding resistance to spirodiclofen, widely used to control P. ulmi populations. Conclusions: The new genomic resources and data that we present in this study for P. ulmi will substantially facilitate molecular studies of underlying mechanisms involved in acaricide resistance. [ABSTRACT FROM AUTHOR]

The aim of the study was to examine the possibility of applying methyl jasmonate (JA-Me) and acibenzolar-S-methyl (BTH) to reduce the population of mites in apple orchards. The experiment was performed on apple trees cv. “Golden Delicious” grown in an orchard according to Integrated Pest Management (IPM) principles. The study showed that of the two elicitors, JA-Me restricted the population of the European red mite (Panonychus ulmiKoch) more strongly than BTH. Neither of these compounds significantly affected the size of the population ofTyphlodromus pyriScheuten – a beneficial predatory mite feeding on spider mites in apple orchards. The study also showed no adverse effects of these compounds on the yield and growth of apple trees, nor on their reproduction as measured by seed production. Studies indicate that the use of methyl jasmonate against spider mites on apple trees can complement the use of conventional acaricides as well as the introduction of predatory mites of the family Phytoseiidae in the protection of apple orchards. [ABSTRACT FROM AUTHOR]

The increasing concern over the continued use of pesticides is pressurising apple growers to look for alternatives to chemical pest control. The re-discovery, and subsequent conservation, of the beneficial predatory mite, Anystis baccarum (Linnaeus) (Acari: Anystidae), in Bramley apple orchards in Northern Ireland offers a potential alternative control component for incorporation into integrated pest management strategies. Anystis baccarum readily feeds upon economically important invertebrate pest species including European fruit tree red spider mite, Panonychus ulmi (Koch) (Acari: Tetranychidae) and show a level of compatibility with chemical pesticides. Recent mis-identification by apple growers of this beneficial mite species had resulted in unnecessary pesticide applications being applied within Northern Irish apple orchards. However, dissemination of information to the apple growers and promotion of the benefits this mite offers in apple orchards has helped to conserve its populations. Apple growers, across the United Kingdom, must be encouraged to be aware of A. baccarum, and indeed all predatory fauna, within their orchards and seek to conserve populations. In doing so, it will ensure that the British apple market remains an environmentally sustainable production system. [ABSTRACT FROM AUTHOR]

A two-part review is presented relating historical tests of the toxicity of pesticides toTyphlodromus pyriand their relevance to modern pest management in New Zealand pome-fruit orchards. Over the past 30 years, the initial need forT. pyrito be resistant to broad-spectrum pesticides has substantially declined as a growing array of new selective chemicals have come into use. In Part 2, a short-term field test is described for determining the toxicity of single applications of pesticides at recommended rates to European red mite (ERM),Panonychus ulmi, and its predator, an organophosphate (OP)-resistant strain ofT. pyrion apples in New Zealand. For each pesticide, changes in mite density were measured from pre-treatment to 2, 7 and up to 25 days post-treatment compared with a water-sprayed control. Density was recorded and analysed for live adult and immature ERM, and live and dead eggs, larvae, nymphs and adults ofT. pyri. Fifteen acaricides, 17 fungicides and 17 insecticides were evaluated. Chemicals more toxic toT. pyrithan ERM were aminocarb, amitraz, binapacryl, chlordimeform, etrimphos, fenvalerate + azinphos-methyl, mancozeb + dinocap, methidathion, methiocarb, omethoate, oxamyl, pirimiphos-methyl and pyrazophos. Chemicals equally or less toxic toT. pyrithan to ERM were acequinocyl, azocyclotin, benzoximate, bromopropylate, chlorpyrifos, clofentezine, cycloprate, cyhexatin, dinocap, mineral oil, propargite, triazophos and vamidothion. The remaining 23 chemicals (primarily fungicides and OP insecticides) had slight or no toxicity to ERM andT.pyri. The short-term field tests provided a useful guide to the long-term effects on ERM andT. pyripopulations of almost all the pesticides. However, the potential disruptive effect of pyrazophos was not found in long-term field trials, and conversely, the apparently harmless dithiocarbamate fungicides were later shown to be highly disruptive when repeatedly sprayed, as in commercial practice. Most of the chemicals tested are no longer used in commercial pome-fruit orchards in New Zealand, all of which now practise integrated fruit production or organic fruit production based on selective pest management methods. The tested pesticides of continuing importance are identified and discussed with special emphasis on the current need to retest for dithiocarbamate resistance inT. pyri, some populations of which have been exposed to these compounds for up to 40 years. This and the changes in pesticide use in New Zealand are paralleled by similar developments in most pome-fruit growing areas of the world. [ABSTRACT FROM AUTHOR]

A two-part review is presented relating historical tests of the toxicity of pesticides toTyphlodromus pyriand their relevance to modern pest management in New Zealand pome-fruit orchards. Over the past thirty years, the initial need forT. pyriresistance to broad-spectrum pesticides has substantially declined as a growing array of new selective chemicals have come into use. In Part 1, a laboratory bioassay is described for determining the toxicity of pesticides to the eggs and larvae of an organophosphate (OP)-resistant strain ofTyphlodromus pyrifrom New Zealand. Apple leaves bearingT. pyriand its preyPanonychus ulmiwere collected from the field. Leaf discs with known numbers of eggs (no active stages) ofT. pyriand prey were cut from the leaves and sprayed with selected pesticides at recommended field rates to simulate field application. The survival of eggs, and the larvae which hatched from them, were recorded for seven days. Thirteen acaricides, 16 fungicides and 15 insecticides were evaluated. Toxic chemicals were aminocarb, amitraz, benomyl, binapacryl, chlordimeform, ethion, omethoate, oxamyl, permethrin, pirimiphos-methyl and triazophos. Slight and variable toxicity was caused by azinphos-methyl, chlorpyrifos, dinocap, mancozeb + dinocap, metiram + nitrothal-isopropyl, and sulphur. No toxicity was detected with the other 24 pesticides. A comparison of the test results with those from field trials in New Zealand showed good agreement, except that the laboratory tests failed to detect the known field toxicity of dithiocarbamate fungicides and the insecticide vamidothion. Most of the chemicals tested are no longer used in commercial pome-fruit orchards in New Zealand, all of which now practise integrated (IFP) or organic (OFP) fruit production based on selective pest management methods. The tested pesticides of continuing importance are identified, and a summary is presented of the international literature describing the impact onT. pyriof the current pesticides used in New Zealand IFP and OFP. The changes in pesticide use in New Zealand are paralleled by similar changes in most pome-fruit growing areas of the world. [ABSTRACT FROM AUTHOR]

Phytophagous mites and their predators were monitored from 1994 to 2000 on a range of cultivars of apple trees under biological fruit production (BFP) and integrated fruit production (IFP) methods, and compared with those on trees sprayed with an organophosphate insecticide programme (OPP). Two-spotted spider mite (TSM) was the dominant mite pest but it remained below economic thresholds under BFP and IFP, primarily through predation byGalendromus occidentalis, assisted by a range of other predatory mites and insects. The latter were largely absent under OPP, and OP-resistantG. occidentaliswere unable alone to prevent TSM from causing unacceptable fruit infestation at harvest in some seasons. High populations of apple rust mite (ARM),Aculus schlechtendali, provided a valuable food source forG. occidentalisunder BFP and IFP that was not available under OPP. Similarly, the use of acaricidal sulphur and lime sulphur as trial fungicides in the BFP orchard greatly reduced ARM density and disrupted phytoseiid control. European red mite (ERM),Panonychus ulmi, caused no economic damage in any production system, primarily because of predation byTyphlodromus pyri. The density of the anthocoridOrius vicinus, which feeds on ERM and TSM, was shown across all three production systems to be dependent on the density of ARM on the foliage, but no such relationship was found for the miridSejanus albisignata. This research has provided further evidence of the need to find alternative disease management strategies for organic production to substitute for the broad-spectrum fungicidal, acaricidal and insecticidal impacts of sulphur and lime sulphur. [ABSTRACT FROM AUTHOR]

To understand the influence of different apple varieties on the development and reproduction of the European red mite, Panonychus ulmi (Koch) (Acari: Tetranychidae), age-stage two-sex life tables of P. ulmi on 'Fuji,' 'Starkrimson Delicious,' 'Golden Delicious,' and 'Granny Smith' varieties were constructed under laboratory conditions at 23 ± 1°C, 75 ± 5% relative humidity, and a photoperiod of 16:8 (L:D) h. Results showed that total development time of immature females was shorter on Fuji than on the other varieties, and this was because of its shorter egg duration. Immature survival of P. ulmi was 74.51-78.00% among four apple varieties, and no significant differences were found. The total fecundity per female was significantly higher on Golden Delicious (34.12 eggs per female) than that on Fuji (27.15 eggs per female), Starkrimson Delicious (25.15 eggs per female), and Granny Smith (20.62 eggs per female). Based on the intrinsic rate of population increase, Fuji and Golden Delicious were more suitable than Starkrimson Delicious and Granny Smith. [ABSTRACT FROM AUTHOR]

Ethanol extracts obtained from the leaf of the thorn apple (Datura stramoniumL.) (Solanaceae) were examined for lethal and repellent properties against adults of the European red mitePanonychus ulmi(Koch) (Acari: Tetranychidae) and its predatorStethorus gilvifrons(Muls.) (Col.: Coccinellidae) under laboratory conditions. The Petri leaf disc-spray tower method was used. The results showed thatD. stramoniumleaf extracts were lethal to both the mite and its predator. Furthermore, an increase in the dose of leaf extract caused a significant increase in the death rates of bothP. ulmiandS. gilvifronsadults. Probit analysis and parameter estimation showed that the LC50values of leaf extract were 7097.5 and 1853.9 mg/l at 24 h residual activity for spider mite and ladybird adults, respectively. The mite and ladybird mortality rates associated with the extract were higher at 48 h than at 24 h, with LC50values of 2013 and 1030 mg/l, respectively. However, the LC90values of the extract were lower for ladybirds than for spider mites at both 24 and 48 h. According to Pearson’s chi-squared test, both spider mite and ladybird adults showed strong aversions to apple leaf surfaces sprayed with sub-lethal doses of the extract (from 13.72 to 1058.0 mg/l). Moreover, an odour test using a two-choice olfactometer demonstrated that ladybird adults prefer fresh air to the extract odour. These results suggest thatD. stramoniumextract can be used effectively as a safer phytopesticidal product for the management ofP. ulmiin both organic and inorganic apple production, but it is not suitable for use in integrated pest management strategies due to its toxic and repellent effects againstS. gilvifrons. [ABSTRACT FROM PUBLISHER]

The functional response of Neoseiulus californicus (McGregor), a phytoseiid predator, was studied on different life stages of twospotted spider mite, Tetranychus urticae Koch, on leaves of apple, Malus domestica Borkh, during a period of 24 hours at 27 ± 2°C and 60% relative humidity. According to Holling's (1959) model, the functional response was Type II. The rate of instantaneous discovery (a') values were 0.9352 for eggs, 0.9260 for larvae, 0.8320 for nymphs, and 0.6786 for female adults, while handling time (Th) values were 0.0122, 0.0116, 0.0126, and 0.0532 for the same stages, respectively. [ABSTRACT FROM AUTHOR]

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The developmental rate and reproductive biology of Neoseiulus californicus, a generalist predator on spider mites and small insects, was investigated in the laboratory at five constant temperatures: 15, 20, 25, 30, and 34°C. The European red mite, Panonychus ulmi, an important pest in Korean apple orchards, was used as prey. Mean developmental time and adult longevity were inversely related to temperature from 15 to 30°C. Lifetime fecundity was greatest at 25°C, whereas daily fecundity was highest at 30°C. The sex ratio (female to male) was highest (0.77) at 25°C and lowest (0.67) at 34°C. Survivorship during immature development varied from 74.3 to 92.9%, with the lowest rate at 34°C. Life table parameters were analyzed and pseudo-replicates for the generation time ( t), the intrinsic rate of natural increase ( r), finite rate of increase (λ), net reproductive rate ( R), and doubling time ( t) were generated using the Jackknife method. Generation time ( t) was lowest (10.7 days) at 34°C, R was highest (49.2) at 25°C, and both r (0.29) and λ (1.34) were highest at 30°C. In conclusion, the development and adult life-history traits obtained for N. californicus fed on P. ulmi indicated significant potential for biological control. [ABSTRACT FROM AUTHOR]

BACKGROUND: Phytophagous mites such as the European red mite, Panonychus ulmi (Koch), are serious pests in European fruit tree orchards, and a number of acaricides are frequently used to control them. Spirodiclofen (Envidor®) has been a commonly used acaricide for several years. In the present study, European field populations collected in 2009 and 2010 were checked for their susceptibility to spirodiclofen by using discriminating dose and full dose response bioassays. RESULTS: In 2009 and 2010, a total of 63 field populations (including winter eggs) of European red mites were collected in different European countries, and in several populations from south-western Germany a shifting in susceptibility against spirodiclofen was observed. Full dose response bioassays on different developmental stages of field-collected strains suggested an age-dependent expression of resistance because eggs remain fully susceptible to spirodiclofen. Artificial selection with spirodiclofen of one of the field strains resulted in resistance ratios of > 7000. Synergism studies suggest a possible role of cytochrome-P450-dependent monooxygenases in spirodiclofen detoxification. Most of the other acaricides from different chemical classes displayed no or low cross-resistance in a spirodiclofen-selected strain. CONCLUSION: In order to preserve spirodiclofen as an important tool in spider mite resistance management, the efficacy situation should be continuously monitored, and it is suggested that spirodiclofen be alternated with acaricides coming from different mode-of-action classes. An observed age-specific expression of resistance revealed full susceptibility of eggs, so targeting spirodiclofen particularly against eggs is likely to reduce the selection pressures imposed on other life stages. Copyright © 2011 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The ladybird beetle Stethorus gilvifrons (Muls.) does not provide sufficient mite control in many of the apple orchards in Bursa, despite being an effective and voracious predator of the European red mite, Panonychus ulmi (Koch). This is due in large part to a heavy dependency on organophosphate (OP) and synthetic pyrethroid (SP) insecticides, which were applied to target key pests. To help understand the effects of the insecticides on the ladybird beetle and its main prey, P. ulmi, this study aims to determine their susceptibilities to the residues of parathion-methyl and bifenthrin and detoxifying enzyme activities, such as carboxylesterase (CarE) and glutathione S-transferase (GST). In addition, the insensitivity of acetylcholineesterase (AChE) to the inhibitors, paraoxon and primicarb, is also determined. There are differences in susceptibility to parathion-methyl, in CarE activity and AChE insensitivity, among the populations of predator ladybird and the spider mite. Although GST might play an important role in detoxifying OPs, there is no relationship between susceptibility to parathion-methyl and bifenthrin and GST activity in both the ladybird and the spider mite. On the other hand, two S. gilvifrons populations were surprisingly tolerant to two insecticides. The disparity in susceptibility to parathion-methyl among the predator populations was due to the responsibility of multiple biochemical resistance mechanisms, including elevated CarE activity and target-site insensitivity. Furthermore, the tolerance of the two populations of ladybirds to bifenthrin was similar to that of two P. ulmi populations collected from the same orchards, which indicates a coadaptation to SPs. Therefore, enhanced detoxification by increased activity of CarE is largely responsible for the observed tolerance to bifenthrin in S. gilvifrons populations. Consequently, these results demonstrate that the ladybird species tend to develop resistance to insecticides in the field. [ABSTRACT FROM AUTHOR]

Herbicide strips are used in apple orchards to promote tree growth and survival, to increase yield and to reduce the risk of rodent damage to tree bark. However, herbicide strips, particularly wider ones, may cause problems including soil erosion, reduced organic matter, leaching of nitrates into ground water and increased incidence of plant diseases and pests, including two-spotted spider mites, Tetranychus urticae Koch. In this 2 year study we monitored mite dynamics in apple trees and used sticky bands on tree trunks to determine rates of T. urticae immigration into Nova Spy apple trees in plots with wide (2 m) or narrow (0.5 m) herbicide strips. Use of wider herbicide strips promoted two risk factors that could trigger outbreaks of tetranychid mites. First, concentrations of leaf N in apple trees were higher and those of P and K were lower with the wide strips. Such changes in nutritional quality of leaves would increase the potential for more rapid population growth of T. urticae, and to a lesser extent, the European red mite, Panonychus ulmi (Koch). Second, there were higher rates of T. urticae immigration from the ground cover vegetation into the trees. In 2006, and for most of 2007, densities of T. urticae were higher with wide herbicide strips, whereas densities of P. ulmi were not enhanced. However, by late August to early September in 2007, densities of both tetranychids were lower with wide herbicide strips. This is because both risk factors were counterbalanced, and eventually negated, by the enhanced action of phytoseiid predators, mostly Typhlodromus pyri Scheuten. From July through September 2006, ratios of phytoseiids to tetranychids were always several-fold lower with wide herbicide strips but in 2007, from mid-July onwards, predator-prey ratios were usually several-fold higher with wide strips. However, this numerical response of phytoseiids to prey density can only occur where the pesticide program in orchards is not too harsh on phytoseiids. Hence the impact of width of herbicide strip is contingent on the composition and size of the phytoseiid complex and the impact of pesticides on predation. [ABSTRACT FROM AUTHOR]

Increasing temperatures are likely to impact ectothermic pests of fruits and nuts. This paper aims to assess changes to pest pressure in California's US$0.7 billion walnut industry due to recent historic and projected future temperature changes. For two past (1950 and 2000) and 18 future climate scenarios (2041-2060 and 2080-2099; each for three General Circulation Models and three greenhouse gas emissions scenarios), 100 years of hourly temperature were generated for 205 locations. Degree-day models were used to project mean generation numbers for codling moth ( Cydia pomonella L.), navel orangeworm ( Amyelois transitella Walker), two-spotted spider mite ( Tetranychus urticae Koch), and European red mite ( Panonychus ulmi Koch). In the Central Valley, the number of codling moth generations predicted for degree days accumulated between April 1 and October 1 rose from 2-4 in 1950 to 3-5 among all future scenarios. Generation numbers increased from 10-18 to 14-24 for two-spotted spider mite, from 9-14 to 14-20 for European red mite, and from 2-4 to up to 5 for navel orangeworm. Overall pest pressure can thus be expected to increase substantially. Our study did not include the possibility of higher winter survival rates, leading to higher initial pest counts in spring, or of extended pest development times in the summer, factors that are likely to exacerbate future pest pressure. On the other hand, initiation of diapause may prevent an extension of the season length for arthropods, and higher incidence of heat death in summer may constrain pest population sizes. More information on the impact of climate change on complex agroecological food webs and on the response of pests to high temperatures is needed for improving the reliability of projections. [ABSTRACT FROM AUTHOR]

Abstract: The annual occurrence and distribution of the predatory bugs Anthocoris nemorum and Anthocoris nemoralis between apple, pear and herbal vegetation, was assessed in three apple orchards in 2001, and in two apple and two pear orchards in 2002. In the laboratory anthocorid prey preference was assessed in two-choice experiments with key pests of apple and pear including pear psyllid, apple psyllid, green apple aphid, rosy apple aphid and red spider mites. Anthocorid predation behavior towards pear psyllids was assessed. Anthocorids were the dominant early season predatory bugs. A. nemorum dominated in apple, while A. nemoralis dominated in pear. A. nemorum was also common in herbal vegetation, especially in mid-summer. Anthocorid numbers were correlated with numbers of collembola, psyllids and aphids in apple, and with numbers of psyllids in pear. A. nemoralis preferred pear psyllid to green apple aphid, while A. nemorum preferred green apple aphid. Both species preferred psyllids to spider mites. The success rate of A. nemoralis in attacking pear psyllids was higher than that of A. nemorum. A. nemorum had two generations in both 2001 and 2002 proving that it can be bivoltine under Danish climate conditions. The mid-summer move by A. nemorum from trees to herbal vegetation suggests that herbal vegetation may maintain A. nemorum in orchards at times of low prey numbers in the trees. Habitat and prey preference trials both identify A. nemorum as a biological control agent of special importance in apple, whereas A. nemoralis is of importance in pear. [Copyright &y& Elsevier]

The functional response of the phytoseiid predator Chileseius camposi González y Schuster, 1962 (Acarina:Phytoseiidae) on densities of its prey Panonychus ulmi (Koch, 1836) was evaluated under controlled temperature (20 ± 2 °C),, relative humidity (75 ± 15%) and photoperiod (16:8h L:D). A functional type II response was displayed (Holling's disk). Holling, Wolf transformation and Rogers models gave similar values for estimating parameters of the Holling's disk equation; however, estimates produced by the Livdahl and Stiven model were higher. Values of attack rate and handling time can be considered within the normal range for phytoseiid generalists. [ABSTRACT FROM AUTHOR]

Non-glandular leaf trichomes positively influence the abundance of many phytoseiid mites. We characterized the influence of grape leaf trichomes (domatia, hairs, and bristles) on Typhlodromus pyri Scheuten abundance over two years in a common garden planting of many grape varieties and 2 years of sampling in a commercial vineyard. In general, a lack of trichomes was associated with much lower predator numbers and in the case of Dechaunac, a cultivar with almost no trichomes, very few T. pyri were found. Phytoseiid abundance was best predicted by a model where domatia and hair had an additive effect (r² = 0.815). Over two years of sampling at a commercial vineyard there were T. pyri present on all of the 5 cultivars except Dechaunac. At the same time, European red mite prey were present on Dechaunac alone. These results suggest that on grape cultivars lacking leaf trichomes, T. pyri likely will not attain sufficient densities to provide biological control of European red mite, despite presence of the mite food source. The relationship between leaf trichomes and phytoseiid abundance that is observed at the scale of single vines in a garden planting appears to also be manifest at the scale of a commercial vineyard. Because persistence of predatory mites in or nearby the habitats of prey mites is important for effective mite biological control, leaf trichomes, through their influence on phytoseiid persistence, may be critical for successful mite biological control in some systems. [ABSTRACT FROM AUTHOR]