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Background: Most studies on efficacy of fungal pathogens and predatory mites against Tetranychus urticae have been done on individual species in the laboratory. We evaluated fungi and predatory mites separately and together against glasshouse populations of T. urticae on chrysanthemum plants. First, effectiveness of the fungal pathogens Beauveria bassiana (Bb88) and Metarhizium anisopliae (Ma129) was compared; then, effectiveness of the predatory mites Phytoseiulus persimilis and Neoseiulus californicus. Based on the results, N. californicus and isolate Ma129 were selected and evaluated in combination. In all experiments, treatment effects were assessed for eggs and motile stages of T. urticae., Results: The first experiment showed no significant effect of either fungal isolate on T. urticae populations, except on plants initially infested with 20 mites, where more eggs were found in the control compared to the fungal treatments. In the second experiment, both predatory mites were equally effective at reducing T. urticae populations compared with the control, regardless of initial T. urticae population density. The last experiment demonstrated that populations of T. urticae were reduced most when M. anisopliae (Ma129) and N. californicus were applied together, compared with the control and when each natural enemy was applied separately., Conclusions: Metarhizium anisopliae (Ma129) and B. bassiana (Bb88) isolates did not have a significant effect on reducing T. urticae populations. Both predatory mites reduced T. urticae populations, regardless of T. urticae density. Combined application of M. anisopliae (Ma129) and N. californicus were more effective against T. urticae than the control or when each agent was applied separately. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Background: In Thailand, the scaly grain mite, Suidasia pontifica Oudemans, impacts the feed industry by emitting a lemongrass-like odor in contaminated feed, reducing its palatability. This study focused on identifying volatile organic compounds (VOCs) associated with this odor in contaminated chicken feeds and ground maize, as well as individual mites using gas chromatography-mass spectrometry (GC-MS). We explored the relationship between VOC concentration and mite population size in chicken feed cultures, aiming to detect minimal mite presence through regression models. Additionally, we tested the sensitivity of nine electronic odor sensors in detecting these VOCs., Results: Our results showed Z-citral and E-citral present in mite-contaminated ground maize, chicken feeds, but absent in uncontaminated samples. Mite populations in chicken feed followed a normal distribution, increasing rapidly, peaking, and then declining, a pattern mirrored in the concentrations of Z-citral and E-citral. Simple linear regression models confirmed a positive correlation between mite density and citral concentrations. Polynomial regression models indicated Z-citral is detectable at mite densities over 67 individuals per gram and E-citral over 3.89 individuals per gram. Odor sensors showed varying readings across different citral concentrations, uncontaminated, and mite-infested chicken feeds., Conclusions: Our study confirms that S. pontifica are responsible for the lemongrass-like odor in infested samples, due to Z-citral and E-citral. The citral concentrations increase with mite population growth and are detectable at low mite densities, suggesting their effectiveness as biomarkers for early mite infestation detection. Additionally, MQ series odor sensors detected these VOCs, indicating their potential for monitoring mite infestations in storage environments. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Background: The biological control agent Phytoseiulus persimilis is a commercialized specialist predator of two agricultural pest mite species Tetranychus urticae and Tetranychus evansi. Biocontrol of these pest species by P. persimilis has achieved success in biological control in some areas. However, the lack of precise information about the influence of global climate change on the worldwide distribution of this biocontrol agent hampers international efforts to manage pest mites with P. persimilis. With 276 occurrence records and 19 bioclimatic variables, this study investigated the potential global distribution of P. persimilis., Results: The results demonstrated that the Maximum Entropy (MaxEnt) model performed well, with the area under the curve being 0.956, indicating the high accuracy of this model. Two variables, the minimum temperature of the coldest month (Bio_6) and precipitation of the coldest quarter (Bio_19) were the most important environmental variables that influenced the distribution of P. persimilis, contributing more than 30% to the model, respectively. The suitable area currently occupies 21.67% of the world's land area, spanning latitudes between 60°S and 60°N. Under shared socio-economic pathway (SSP) 5-8.5 (high-carbon emissions), the low suitable area would increase by 1.31% until the 2050s., Conclusion: This study successfully identified that south-eastern China, parts of countries in the Mediterranean coastal regions, including Libya, Algeria, Portugal, Spain, and France, are climatically favorable regions for P. persimilis, providing valuable information about the potential areas where it can be effectively exploited as biocontrol agents in classical biological control programs to manage pest spider mites environmentally friendly. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Background: Biological control with predatory mites is applied against pests in greenhouse crops. Chemical control with the use of selective, reduced-risk pesticides, is an important component of Integrated Pest Management (IPM) programs, that often needs to be combined with biological control. Here, we evaluated the effect of plant pollen when used as supplementary food on the survival, reproduction and predation of the predatory mite Amblydromalus limonicus (Acari: Phytoseiidae) after exposing young larvae and adults to flonicamid, an insecticide of moderate toxicity to phytoseiids. Pollen is an important alternative food for generalist phytoseiids ensuring survival and supporting populations build-up during periods of prey scarcity. Two regimes of cattail (Typha angustifolia L.) pollen differing in application frequency were used. In the first, the total amount of pollen was supplied once, within 30 min after insecticide application, whereas in the second regime, the same amount of pollen was supplied gradually, i.e., every 48 h., Results: Regardless of the frequency of application, pollen provisioning results in a reduction in prey (thrips) consumption relative to the control (no pollen provisioning). Nevertheless, when adult mites were directly exposed to flonicamid residues, pollen provisioning attenuated the reduction in prey consumption as compared to the control. In addition, the gradual (every 48 h) provisioning of pollen to adult predators exposed to flonicamid residues impacted positively the intrinsic rate of population increase (r m ) of A. limonicus as compared to when feeding on prey., Conclusion: Our results reveal an unexpected role of pollen provisioning in alleviating pesticides side-effects on phytoseiids. © 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2024 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Background: Rice is one of the most consumed cereals in the world. Productivity losses are caused by different biotic stresses. One of the most common is the phytophagous mite Schizotetranychus oryzae Rossi de Simons (Acari: Tetranychidae), which inhibits plant development and seed production. The identification of plant defense proteins is important for a better understanding of the mite-plant interaction. We previously detected a high expression of Osmotin1 protein in mite-resistant rice cultivars, under infested conditions, suggesting it could be involved in plant defense against mite attack. We therefore aimed to evaluate the responses of three rice lines overexpressing Osmotin1 (OSM1-OE) and three lines lacking the Osmotin1 gene (osm1-ko) to mite attack., Results: The numbers of individuals (adults, immature stages, and eggs) were significantly lower in OSM1-OE lines than those in wild-type (WT) plants. On the other hand, the osm1-ko lines showed larger numbers of mites per leaf than WT plants. When plants reached the full maturity stage, two out of the three infested OSM1-OE lines presented lower plant height than WT, while the three osm1-ko lines (infested or not) presented higher plant height than WT. The reduction in seed number caused by mite infestation was lower in OSM1-OE lines (12-19%) than in WT plants (34%), while osm1-ko lines presented higher reduction (24-54%) in seed number than WT plants (13%)., Conclusion: These data suggest that Osmotin1 is involved in rice resistance to S. oryzae infestation. This is the first work showing increased plant resistance to herbivory overexpressing an Osmotin gene. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Background: Structural and chemical plant defence traits may reduce the efficacy of biological control agents in integrated pest management. Breeding programmes have shown arthropod predators' potential to acclimate to challenging host plants. However, whether and how these predators adapt to novel plant environments remain unclear. Using the predatory mite Phytoseiulus persimilis - herbivorous mite Tetranychus urticae system in an experimental evolution setup, we studied the adaptation mechanisms to tomato and cucumber, plants that possess a distinct repertoire of defensive traits., Results: Experimental evolution experiments on whole plants revealed that allowing P. persimilis to adapt to tomatoes led to an ~100% larger population size. Independent feeding assays showed that tomato- and cucumber-adapted prey reduced predator fecundity. The deleterious effect of ingesting low-quality prey persisted after adaptation of the predator to both cucumber and tomato. We demonstrated that jasmonic acid (JA)-dependent defences reduce prey quality by evaluating predator performance on prey fed on JA defence-deficient tomato plants. Transcriptomic profiling of the replicated P. persimilis lines showed that long-term propagation on tomato and cucumber plants produces distinctive gene-expression levels. Predator adaptation to tomatoes results in the loss of a large transcriptional response, in which predicted cuticle-building rather than detoxification pathways are affected., Conclusion: We showed that the adaptation of predatory arthropods to a novel, challenging plant does not necessarily occur via the prey, but rather through the physical environment of the plant. We provided first insights into the underlying molecular mechanisms. © 2023 Society of Chemical Industry., (© 2023 Society of Chemical Industry.)

Background: A thorough knowledge of the population dynamics of pests and of the main factors affecting population growth is an important prerequisite for the development of effective control strategies. Failures of various treatments aimed at regulating populations of Dermanyssus gallinae are regularly reported in poultry farms and pullulations occur very quickly after first detection. To finely characterize population dynamics of D. gallinae, and to identify the factors modulating population growth, we conducted two successive multi-generation experiments using closed mesocosms equipped with or without automatic counters and housing a host full- or part-time (three nights per week)., Results: Population growth was very rapid and the adult to juvenile ratio very different from the prediction by a mathematical model. A male-biased sex ratio was observed in some mesocosms from 21 days and in most mesocosms from 35 days of population growth originating from an inoculum of adult females. A dramatic slowdown in growth was measured in mesocosms equipped with trackers, where the mites' path to the host was constrained. The slowdown in population growth induced by the intermittent presence of the host compared to its full-time presence was much less marked., Conclusion: These findings suggest avenues of research for new management methods. They question the relevance of a critical threshold based on traditional trap monitoring to manage D. gallinae. Our results highlight a unique characteristic of D. gallinae that makes it a recalcitrant case to threshold-based practices recommended for integrated pest management (IPM) against other arthropod pests. The dramatic effect of a physical constraint for the mite to access the host (unnatural constrained path) confirms an observation made in 1917 and is a reason to design perches that are less conducive to parasite traffic. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Background: Quantifying how chemical tolerance of pest arthropods varies with temperature is important for understanding the outcomes of chemical control, for measuring and monitoring resistance, and for predicting how pesticide resistance will evolve under future climate change. We studied the redlegged earth mite, Halotydeus destructor (Tucker), a winter-active invasive agricultural pest in Australia. Using a replicated block experiment, we tested the effect of different thermal conditions on the expression of chemical tolerance to a pyrethroid and two organophosphates. Our chemical bioassays were conducted on two redlegged earth mite populations: one possessed organophosphate resistance, whilst the other was susceptible to pesticides. Mites were first acclimated at cool (4 °C) and warm (14 °C) conditions and then exposed to pesticides in both cool (11 °C) and warm (18 °C) test conditions., Results: Warm test conditions generally reduced chemical tolerance to all pesticides relative to cool test conditions. Median lethal dose (LD 50 ) values of mites tested under cool conditions were 1.12-3.57-fold greater than of mites tested under warm conditions. Acclimation had a variable and small impact on chemical responses. Thermal factors (ratio between test temperatures) were similar between populations for each active ingredient. Despite reduced chemical tolerances under warm test conditions for individual mite populations, resistance factors (ratio between resistant and susceptible mite populations) were relatively consistent., Conclusion: Our data provides context for prior theoretical work demonstrating climatically constrained pesticide resistances in Australian redlegged earth mites. Estimates of temperature dependent toxicity measured in this study may be useful in parameterizing models of redlegged earth mite control under an increasingly warm and more variable climate. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., (© 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.)

Background: Empoasca onukii, the tea green leafhopper, is a key pest of tea whose control often requires the extensive use of insecticides. As a predator of the tea green leafhopper, the mite Anystis baccarum is a potential biological control agent worldwide, though little is known about how intercropping cover crops can impact its suppressing effect on E. onukii. Therefore, we conducted a field experiment to investigate how the relationship of the abundance of the predatory mite and its leafhopper prey is influenced by two different cover crops and a manually weeded inter-row treatment as a contrast to naturally growing vegetation in a tea plantation in China., Results: The abundance of A. baccarum was significantly higher in tea canopies of intercropped treatments than in canopies over natural ground cover. Litter samples showed higher abundances of A. baccarum when tea was intercropped with Paspalum notatum than with natural ground cover in the first year of treatment. The abundance of E. onukii in tea canopies was higher over the bare ground treatment in the first year but the opposite was observed in the second year., Conclusions: Results suggest that the abundance of A. baccarum in a tea plantation is influenced by intercropping and it can affect its leafhopper prey, albeit with varying levels of suppression. For informing biological control and suppression of pests, long-term experiments are needed to investigate the interactions of both pest and predator with cover crop treatments. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Background: Tomato/potato psyllid (TPP), Bactericera cockerelli (Šulc), is a recently established invasive pest of solanaceous crops in New Zealand. No alternative control strategies are available against TPP due to the development of insecticidal resistance. We investigated the combined use of the predatory mites Amblydromalus limonicus or Neoseiulus cucumeris with either the fungus Beauveria bassiana (suspensions and dry conidia) or with Typha orientalis pollen as a control of TPP in greenhouse bell pepper over 7 weeks., Results: All treatments significantly reduced TPP densities compared with the control. A. limonicus resulted in significantly lower TPP densities than any other combination with N. cucumeris. B. bassiana suspensions did not affect A. limonicus densities when they were combined. However, the application of dry B. bassiana conidia significantly reduced the densities of A. limonicus. The use of T. orientalis pollen resulted in significantly higher densities of A. limonicus but densities of N. cucumeris did not increase. The combined use of A. limonicus with B. bassiana suspensions or T. orientalis pollen resulted in significantly decreased TPP populations and greater crop yield., Conclusion: The synergistic application of A. limonicus with B. bassiana suspensions could be a suitable strategy to control TPP in the greenhouse. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Background: A wide range of supplementary food resources can be offered to generalist predatory mites to improve their survival and reproduction and enhance their persistence in the environment. We investigated the relative suitability of different pollen types for the survival and reproduction of Neoseiulus californicus and its life history on a mixed diet of pollen and prey. We also evaluated the population dynamics of Tetranychus urticae in the presence of N. californicus with or without pollen, and in comparison to Phytoseiulus macropilis., Results: Survival and reproduction of N. californicus adults were satisfactory on exclusive diets of T. urticae, cattail pollen, palm pollen and bee pollen. However, mites did not reproduce when fed only pollen during both immature and adult stages. Both predatory mites successfully controlled T. urticae. Although the specialist P. macropilis was more efficient in suppressing the pest population in the short term, it abandoned plants at low prey densities, whereas N. californicus performed better and persisted longer under prey scarcity., Conclusion: N. californicus is an efficient biological control agent of T. urticae and the provision of supplementary food could retain them in the crop prior to the arrival of the pest or in periods of prey scarcity. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Background: Parasitus bituberosus is common in rose fields and nearby vegetation around Bogotá. In rearing units, it is often aggregated, feeding on Frankliniella occidentalis edaphic phases. Preliminary observations suggested predator immatures can not reach adulthood if isolated. The objectives were to evaluate the suitability of F. occidentalis as prey for P. bituberosus, to evaluate free-living nematodes as complementary food, and to confirm the aggregation effect on predator biology. Aggregation types: (1) isolated mites, (2) mites paired only as deutonymphs and early adulthood, and (3) mites always paired. Diets: thrips (T), nematodes (N) and thrips + nematodes (NT)., Results: Parasitus bituberosus juveniles did not feed on live F. occidentalis, but developed and oviposited on nematodes. Approximately 77% of the isolated mites died as immatures. Mortality was low (21-23%) when predators were paired at least in the deutonymph and the early adult phase. Female daily predation rates were comparable to other predators on F. occidentalis (≥2.5). Continuously paired mites had high biotic potential, especially when the diet included nematodes (r m  ≥ 0.33; R o  ≥ 33.90; daily oviposition rate ≥ 10.9)., Conclusion: The results of this study warrant further investigation of this predator, to evaluate methods for its mass production, inclusion in conservation biocontrol programs and performance against the pest at a larger scale. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

Background: Zoophytophagous predators can trigger plant defenses affecting prey populations beyond predation. Euseius stipulatus is a presumed zoophytophagous phytoseiid common in citrus. The response of citrus to one of its potential prey, Tetranychus urticae, is genotype dependent, with Citrus reshni and C. aurantium exhibiting extreme susceptibility and resistance, respectively. Volatile blends produced upon infestation affected the behavior of these two mites. We wondered whether E. stipulatus could trigger similar responses., Results: Euseius stipulatus triggered genotype-dependent defense responses in citrus. Whereas C. aurantium upregulated the Jasmonic Acid, Salicylic Acid and flavonoids defensive pathways, C. reshni upregulated JA only. Likewise, different volatile blends were induced. These blends were exploited by E. stipulatus to select less-defended plants (i.e., those in which higher pest densities are expected) and, interestingly, did not prevent T. urticae from choosing E. stipulatus-infested plants. To the best of our knowledge, this is the first time that this type of response has been described for a zoophytophagous phytoseiid., Conclusion: The observed responses could affect herbivore populations through plant-mediated effects. Although further research is needed to fully characterize them and include other arthropods in the system, these results open opportunities for more sustainable and effective pest control methods (i.e., combining semiochemicals and biological control). © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Predator-prey interactions consist of direct consumption of prey by predators and indirect non-consumptive effects on prey. Predator cues can induce predation stress in prey that negatively influences the survival, development, reproduction, and feeding behaviour of the prey. This study evaluated the effects of hemipteran-tending ant (Technomyrmex albipes) odour on the development, survival, reproduction, and predation rates of the predatory mite Amblydromalus limonicus when feeding on an invasive pest of solanaceous crops, Bactericera cockerelli. The age-stage, two-sex life table theory was used to compare the demographic characteristics and predation rates of A. limonicus in the presence and absence of ant odour., Results: We show that exposure to ant odour did not alter the development, survival rate, and fecundity of A. limonicus, but induced a sexually dimorphic response in its longevity; consumption rates also showed that dimorphic response-predation rates increased in female A. limonicus, but not in males., Conclusion: To our knowledge, this is the first report indicating increased consumption rates by natural enemies exposed to odour from a mutualist of pest (ant). This finding may provide new insights into understanding tri-partite interaction involving a pest, its predator, and a mutulist of the pest. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Tetranychus evansi and T. urticae spider mites are known major pests of Solanaceae. Smallholders in Africa rely heavily on pesticide treatments. However, farmers claim that pesticides are generally ineffective despite high-frequency sprays. New management solutions are thus urgently needed. This study assessed the efficacy of using acaricide-treated nets combined with predatory mite release for controlling spider mites., Results: The results showed the acaricide-treated net alone was more effective at reducing numbers of T. urticae than T. evansi. We observed the opposite for release of the predatory mite Phytoseiulus longipes. This difference could be explained by the specific dispersion strategies of the two spider mite pests; T. evansi is gregarious, whereas T. urticae dispersed rapidly. Joint application of both techniques resulted in a synergetic effect that reduced T. evansi and T. urticae spider mite numbers close to zero. The synergetic effect could be explained by predator avoidance behaviour of the prey spider mites, resulting in higher prey trapping and killing rates on acaricide-treated nets, while P. longipes fed on spider mite eggs., Conclusion: These techniques are profitable for smallholders as they are not expensive and avoid residues on the crop. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Management of tomato potato psyllid (TPP; Bactericera cockerelli (Šulc)) predominantly relies on insecticides. However, biological control agents (BCAs) could provide viable alternatives to suppress TPP populations. In this laboratory experiment, we assessed the predatory mite Amblydromalus limonicus (Garman & McGregor) as a BCA of TPP on whole plants of two tomato and two pepper cultivars over a 5-week period., Results: Plant species and cultivar had a significant effect on the ability of A. limonicus to suppress populations of TPP. Numbers of TPP were suppressed by A. limonicus on four pepper treatments, but on only one tomato treatment. Amblydromalus limonicus could survive and reproduce on pepper and tomato, but more were found on pepper at the end of the 5-week period., Conclusion: Amblydromalus limonicus has the potential to suppress TPP populations on pepper but not tomato cultivars, based on the present study. Possible reasons for these results include the difference in leaf morphology between species, and higher predator:prey ratios on pepper than tomato because of the longer TPP generation time on pepper. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: Several phytoseiid species can potentially control the citrus rust mite (CRM). Their effectiveness varies, however, as do their intraguild interactions. Under laboratory conditions, Euseius stipulatus, E. scutalis and Iphiseius degenerans preyed effectively on CRM, whereas Amblyseius swirskii and Typhlodromus athiasae had no effect on CRM. In combination with A. swirskii, Euseius numbers were reduced due to intraguild predation, and consequently CRM suppression was less effective. In the field, predatory mite species can be variably provisioned by windborne pollen released from cover crops such as Rhodes grass (RG). We aimed to determine the effects of RG on the phytoseiid community in two field experiments, on different cultivars (pomelo and Shamouti orange). We also tested these communities for negative interspecific abundance relationships that are expected if their respective laboratory-observed intraguild interactions are manifested in the field., Results: Overall, on pomelo, we observed a dominance of A. swirskii, relatively low E. stipulatus and high CRM abundances. Amblyseius swirskii and E. stipulatus abundances were both elevated near RG, despite apparent intraguild predation by A. swirskii. Conversely, T. athiasae abundances were lower near RG, likely due to predation by A. swirskii. On Shamouti, E. stipulatus abundances were much higher than on pomelo and were not negatively related to A. swirskii abundances. There, RG increased E. stipulatus abundance, and CRM was reduced., Conclusion: RG cover cropping can enhance CRM control, depending on variation in intraguild interactions among phytoseiids, particularly between A. swirskii and E. stipulatus. These may be modulated by climatic and/or cultivar effects. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: The polyphagous mite pest, Halotydeus destructor, typically has three generations during the cool moist season in Australia and produces over-summering diapause eggs in spring. Diapause eggs have a distinct thick and dark chorion and can survive heat, desiccation and the application of pesticides. Farmers suppress mites producing diapause eggs by a carefully timed spring pesticide application using Timerite ® , which predicts the onset of diapause egg production based largely on day length. We investigated the association between diapause induction and other environmental factors that may complicate diapause predictions., Results: Diapause in H. destructor induction was influenced by three interacting environmental factors, namely day length, temperature and soil moisture. A cryptic type of diapause egg that lacked a thick chorion and was instead morphologically similar to non-diapause eggs was also discovered. Like diapause eggs, this newly discovered egg type could also survive hot and dry summer conditions., Conclusions: There is an opportunity to refine the Timerite ® spring spray by incorporating knowledge of other environmental factors inducing diapause in H. destructor. Compared with typical diapause eggs, the production of cryptic diapause eggs could reflect a strategy to deal with diversifying environmental stresses and/or represent a bet-hedging strategy to adapt to unpredictable environments. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: An understanding of the causes and consequences of dispersal is vital for managing populations. Environmental contaminants, such as pesticides, provide potential environmental context-dependent stimuli for dispersal of targeted and non-targeted species, which may occur not only for active but also for passive dispersal, although such a possibility is frequently neglected. Here, we assessed the potential of food deprivation and acaricides to interfere with the take-off for passive (wind) dispersal of the predatory mite Neoseiulus baraki., Results: Wind tunnel bioassays indicated that starvation favoured the take-off for wind dispersal by the mite predator, which also varied with wind velocity, and dispersal increased at higher velocities within the 1-7 (m s -1 ) range tested. For the acaricides tested, particularly the biopesticide azadirachtin but also abamectin and fenpyroximate, the rate of predator take-off for dispersal increased, and further increased with wind velocity up to 7 m/s. Such responses were associated with changes in the predator behavioural preparation for wind-mediated passive dispersal, with a greater incidence of the standing posture that permitted take-off., Conclusion: The rate of take-off for passive dispersal by N. baraki increased with food deprivation and exposure to the residues of agricultural acaricides. Azadirachtin exposure resulted in a particularly strong response, although abamectin and fenpyroximate also stimulated dispersal. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Background: In integrated pest management systems in greenhouse crops, the predatory mite Amblyseius swirskii is becoming increasingly important as a biological control agent of various pests, especially thrips and whiteflies. An emerging strategy to promote the predator's establishment and retention in the crop consists in providing food supplements. However, when faced with omnivorous pests, such as the western flower thrips, Frankliniella occidentalis, food supplements need to be applied with extreme care, in order not to boost population growth of the pest. This laboratory study was conducted to evaluate the impact of commercial products of Typha angustifolia pollen and decapsulated brine shrimp cysts (Artemia sp.) on populations of both pest and predator and on predator-prey interactions., Results: Pollen was highly supportive for both F. occidentalis and A. swirskii, whereas Artemia cysts supported thrips populations to a lesser extent than those of the predator. Furthermore, a less pronounced reduction in thrips consumption by A. swirskii was observed in the presence of Artemia cysts as compared with T. angustifolia pollen., Conclusion: Artemia might be a valuable alternative to pollen for supporting populations of A. swirskii in order to improve thrips management, as they are less beneficial for the pest but do support population growth of A. swirskii., (© 2015 Society of Chemical Industry.)

Background: A key component for spray decision-making in IPM programmes is the establishment of economic injury levels (EILs) and economic thresholds (ETs). We aimed to establish an EIL for the redlegged earth mite (Halotydeus destructor Tucker) on canola., Results: Complex interactions between mite numbers, feeding damage and plant recovery were found, highlighting the challenges in linking H. destructor numbers to yield. A guide of 10 mites plant(-1) was established at the first-true-leaf stage; however, simple relationships were not evident at other crop development stages, making it difficult to establish reliable EILs based on mite number. Yield was, however, strongly associated with plant damage and plant densities, reflecting the impact of mite feeding damage and indicating a plant-based alternative for establishing thresholds for H. destructor. Drawing on data from multiple field trials, we show that plant densities below 30-40 plants m(-2) could be used as a proxy for mite damage when reliable estimates of mite densities are not possible., Conclusion: This plant-based threshold provides a practical tool that avoids the difficulties of accurately estimating mite densities. The approach may be applicable to other situations where production conditions are unpredictable and interactions between pests and plant hosts are complex., (© 2015 Society of Chemical Industry.)

Background: An acaricidal effect of lime sulfur has not been demonstrated for Polyphagotarsonemus latus. However, lime sulfur can cause toxicity to natural enemies and to host plants. In this study, the toxicity of different concentrations of lime sulfur to P. latus, to the predatory mite Amblyseius herbicolus and to the predatory insect Chrysoperla externa was evaluated. Additionally, the phytotoxicity of lime sulfur to two P. latus hosts, chili pepper and physic nut plants, was determined., Results: Lime sulfur at a concentration of 9.5 mL L(-1) restrained P. latus population growth. However, this concentration was deleterious to natural enemies. The predatory mite A. herbicolus showed a negative value of instantaneous growth rate, and only 50% of the tested larvae of C. externa reached adulthood when exposed to 10 mL L(-1) . Physic nut had severe injury symptoms when sprayed with all tested lime sulfur concentrations. For chili pepper plants, no phytoxicity was observed at any tested concentration., Conclusion: Lime sulfur might be used for P. latus control on chili pepper but not on physic nut owing to phytotoxicity. Care should be taken when using lime sulfur in view of negative effects on natural enemies. Selective lime sulfur concentration integrated with other management tactics may provide an effective and sustainable P. latus control on chili pepper., (© 2012 Society of Chemical Industry.)

Background: Plasma treatment enables effective binding of chitosan film to textile fibres. Heavy metal ions such as Ag(+) adsorbed onto the chitosan coating are known to enhance toxicity to microorganisms. The acaricidal effect of chitosan and chitosan/metal adducts with Ag(+) , Zn(2+) and Cu(2+) was tested in laboratory experiments. Tested species Acarus siro, Dermatophagoides farinae, D. pteronyssinus and Tyrophagus putrescentiae are allergen producers and important pests in house dust, stored food and feed. The mortality was compared after 24 h of exposure of mites to plasma-treated textiles., Results: Chitosan/Ag(+) textile caused at least 80% mortality of all species tested. Chitosan/Zn(2+) and chitosan/Cu(2+) textiles had a smaller effect on mite mortality than chitosan/Ag(+) . The conversion of chitosan/Ag(+) finishing to chitosan/Ag2 O did not influence the mortality of mites in biotests, except that of Tyrophagus putrescentiae, where the mortality decreased from 86 to 64%., Conclusion: The results support a great potential of chitosan/Ag(+) fibres in acaricidal materials and/or mite protective food packages., (© 2012 Society of Chemical Industry.)

Background: Leprosis is one of the most serious citrus plant diseases. Leprosis-affected plants, especially sweet orange [Citrus sinensis (L.) Osbeck], which is the most widely cultivated citrus fruit worldwide, show reduced photosynthetic capacity and severe defoliation. The aim was to evaluate the relationship between the Brevipalpus phoenicis (Geijskes) vector mite and citrus leprosis disease in Pera sweet orange plants grafted on different rootstocks. Data were analysed using numerical classification and conventional statistical analysis (ANOVA)., Results: Both viruliferous and non-viruliferous B. phoenicis populations increased in number on plants maintained at low soil water content. Among the evaluated rootstocks, Sunki mandarin proved least favourable for mite population increase. Furthermore, the viruliferous mite population increased more rapidly than the non-viruliferous mite population., Conclusion: The Cleopatra rootstock showed low variability in leaf nitrogen content, low mite number and low leprosis severity, thereby producing the most favourable results. Under appropriate moisture conditions, the Sunki rootstock produced the best results, showing the least severe leprosis. Rangpur lime rootstock grown in soil with varying water content showed the greatest variation in foliar nitrogen content, mite number and severity of leprosis and is considered to be the most difficult rootstock to manage., (Copyright © 2012 Society of Chemical Industry.)

Background: Predatory mites (Amblyseius swirskii Athias-Henriot, Typhlodromips montdorensis Schicha, Neoseiulus cucumeris (Oudemans) and Iphiseius degenerans Berlese) were investigated for their potential to act as control agents for Thrips palmi Karny. Prey consumption rates and compatibility with pesticides were assessed., Results: Second-instar larvae were the preferred life stage. Typhlodromips montdorensis consumed the most larvae (2.8) and also an average of 1.2 adult T. palmi per 5 day period. Both 24 and 48 h assessments following application of abamectin, spinosad and imazalil demonstrated mortality of predatory mites (across all species), which was significantly higher than with the other treatments (P < 0.001). Spraying with pymetrozine did not provide any increased mortality when compared with the water control. Application of thiacloprid proved detrimental only to I. degenerans. Following indirect exposure of predatory mites to pymetrozine and imazalil, no significant differences in mite mortality were obtained. Indirect exposure to spinosad was identified as the most detrimental treatment (P < 0.001) to all mites. Abamectin also proved detrimental, with only T. montdorensis showing any potential tolerance., Conclusion: All predatory mites investigated offer potential for controlling T. palmi. Compatibility with chemicals varied between the mites. The potential of incorporating the mites into eradication strategies for T. palmi is discussed., (Copyright © 2012 Society of Chemical Industry.)

Background: The redlegged earth mite, Halotydeus destructor Tucker, is an important pest of broad-acre farming systems in Australia, New Zealand and South Africa. In 2006, high levels of resistance to synthetic pyrethroids were discovered in this species in Western Australia., Results: Between 2007 and 2010, the authors monitored resistance in field populations and found it had spread considerably within the state of Western Australia. Twenty-six paddocks from 15 individual properties were identified with resistance, and these paddocks ranged over 480 km. To date, resistance has not been detected in any other Australian state. Resistance in H. destructor appears to be found across the entire pyrethroid group, but not to other chemical classes such as organophosphates and carbamates, or other chemistries with novel modes of action., Conclusion: The high levels of resistance occurring in Western Australia have caused considerable economic losses due to ineffective chemical applications and mortality of crop plants at seedling establishment. These findings highlight the need for a comprehensive resistance surveillance programme to be developed for H. destructor within Australia. Growers need to consider non-chemical approaches for pest control and should be encouraged to implement pesticide resistance management programmes for H. destructor., (Copyright © 2011 Society of Chemical Industry.)

Background: Citrus red mite, Panonychus citri (McGregor), is a key pest of San Joaquin Valley California citrus. Spirodiclofen was registered for mite control in 2007, and spirotetramat for scale control in 2008. Because of the potential for resistance to spirodiclofen to develop in spider mites, and cross-resistance to spirotetramat used for other citrus pests, bioassay methods for resistance monitoring were developed., Results: The responses of four populations of adult female, egg and larval stages of P. citri to spirodiclofen were compared to determine the most robust bioassay method for this pesticide. Adult females responded with a higher LC(99) and larval stages exhibited higher control mortality and a lower slope of response compared with the egg stage. Thus, the egg stage was found to be the most suitable stage for testing. Egg production and egg shape were significantly affected by spirodiclofen treatment of adult female mites. Bioassays with the related compound spirotetramat revealed that P. citri egg hatch was less affected by this compound, requiring the assessment of mortality to be extended to 11 days after treatment when the hatched larvae succumbed to the pesticide. Discriminating concentrations of 10 ppm for spirodiclofen and 31.6 ppm for spirotetramat in an 11 day bioassay were tested against eight field populations of P. citri, and 99-100% mortality resulted., Conclusion: These results provide a baseline for the response of P. citri to spirodiclofen and spirotetramat that will aid resistance management in California citrus., (Copyright © 2011 Society of Chemical Industry.)

Background: Mushroom cultivation may be adversely affected by insect pests, including sciarids (Lycoriella spp.), which were previously controlled by application of chemical pesticides. However, owing to food safety and environmental concerns, availability of pesticides for use during mushroom cultivation has diminished. Consequently, it is imperative to investigate alternative control strategies, not reliant on chemical pesticides, which may be used in an integrated pest management system., Results: Application of the predatory mite Hypoaspis miles Berlese to commercial mushroom-growing beds at the beginning of spawn run or just prior to casing (830 mites m(-2)) significantly reduced immature sciarids, Lycoriella ingenua (Dufour), in the growing substrate and also adult activity towards the conclusion of cropping. A trend towards lower sciarid emergence from substrates and reduced adult sciarid activity was observed following the application of Steinernema feltiae (Filipjev) (1.5 x 10(6) nematodes m(-2)) at casing. No significant treatment effects on mushroom yield were observed. However, contamination of the mushroom crop by adult sciarids increased in untreated controls. Application of H. miles required a 12-fold increase in labour when compared with application of S. feltiae., Conclusion: Contingent upon the development of an effective application system, H. miles has potential for the biological control of sciarids in commercial mushroom production., ((c) 2009 Society of Chemical Industry.)

The production of crops under protected conditions is increasing worldwide. Owing to growing consumer demands for healthy and green produce, and intensifying pesticide resistance, non-chemical solutions--foremost among which is biological control--are being sought. The authors review recent advances related to the application of predatory mites for the control of greenhouse pests, and discuss interactions among acarine biocontrol agents (ABAs) and the effects of crop plants and new technologies on ABAs, such as artificial lighting, elevated carbon dioxide levels and genetically modified organisms. This is followed by a discussion of the problems associated with the search for and use of new ABAs, including management, the benefits of modelling and avenues of future research., (Copyright (c) 2007 Society of Chemical Industry.)