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Agriculture sector of Saudi Arabia is growing swiftly and tomato is an important crop cultivated mostly under green houses. Unfortunately, it is facing severe infestation due to divers mite species. Present study, relates to evaluation of toxicity of oxamyl against two phytophagous mites; Aculops lycopersici and Tetranychus urticae, isolated from tomato plants suffering from infestation. Simultaneous effect of oxamyl on two predatory mites; Neosiulus cucumeris and Euseius scutalis, was also evaluated. Three concentrations of oxamyl; half of the recommended dose (HRD), recommended dose (RD) and double recommended dose (DRD), were used against each mite specie to observe mortality within seven days as compared to the control. Significant mortality of 97.91% and 93.92% was observed in A. lycopersici and T. urticae, respectively at RD. In case of predatory mites; N. cucumeris and E. scutalis, mortality was 60.61% and 64.48%, respectively, under same conditions. Mortality of mites observed at HRD was insignificant and there was negligible increase in mortality at DRD. Oxamyl being less toxic to predatory mites and significantly mortal to phytophagous mites is recommended as a tool to as a tool to achieve biological control parallel to pesticidal effect.

Domates pas akarı, Aculops lycopersici (Massee) (Acari: Eriophydae) domatesin önemli zararlılarından biridir. Domates bitkisinde yaprak, sap ve gövdede paslanmaya ve kurumalara neden olarak meyvenin ekonomik değerini ve verimini düşürmektedir. Bu nedenle, domateste zararlının mücadelesinde biyolojik mücadelenin kullanımı bu tezin ana konusudur. Bu çalışmanın amacı 2020-2021 yıllarında laboratuvar koşullarında 2 sırık çeşit (TGB230312, BT-TAYLİN) ve 2 oturak çeşit (RİO GRANDE, SC2121) üzerinde Neoseiulus californicus (McGregor)’un A. lycopersici ile beslenmesi sonucu avcının hayat tablosu ve avlanma kapasitesi parametrelerinin, sayısal ve işlevsel tepkilerinin incelenmesidir. Tezin ikinci bir amacı ise 2021 yaz-sonbahar sera koşullarında aynı domates çeşitlerinde yapay olarak bulaştırılan A. lycopersici’ye karşı N. californicus salımı (avcı:av; 1:20) yapıldıktan sonra zararlı ve avcının popülasyonlarının izlenmesidir. Neoseiulus californicus’un A. lycopersici üzerinde beslenmesi sonucunda farklı domates çeşitlerinde 1,15-1,43 günde yumurtalarının açıldığını, ortalama 5,96-6,27 günde bırakılan yumurtaların %74-97’sinin ergin olduğu, ergin dönemde dişi başına toplam 2,17-7,73 yumurta bıraktığı, net üreme gücünün (R0) 1,91-9,71, kalıtsal üreme yeteneğinin (rm) 0,043-0,136, artış oranı sınırı (λ) 1,04-1,15 ve ortalama döl süresinin (T0) 15,09-16,77 gün arasında değiştiği bununla birlikte işlevsel tepkisinin Tip II olduğu belirlenmiştir. Onbeş gün ara ile yapılan dört salımın arkasından salım yapılmayan kontrol parsellerine göre N. californicus salımı yapılan parsellerde önemli düzeyde A. lycopersici popülasyonu düşük bulunmuştur. Kontrol parsellerindeki en yüksek A. lycopersici popülasyonu haziran ortası ve eylül ortasında görülürken N. californicus salımı yapılan parsellerde sadece haziran ortasında görülmüştür. Ayrıca en yüksek N. californicus popülasyonları da eylül ortası ve sonunda belirlenmiştir. Bu sonuçlar, ardışık salımlardan sonra N. californicus’un A. lycopersici popülasyonunu baskıladığını göstermiştir. Tomato rust mite, Aculops lycopersici (Massee) (Acari: Eriophydae) is one of the important pests of tomato. It reduces the economic value and yield of the fruit by causing rusting and drying on the leaves and stems of the tomato plant. Therefore, the use of biological control of pests in tomato is the main subject of this thesis. The aim of this study is to investigate the feeding of Neoseiulus californicus (McGregor) with A. lycopersici on 2 indeterminate cultivars (TGB230312, BT-TAYLİN) and 2 determinate cultivars (RİO GRANDE, SC2121) of tomato plants under laboratory conditions and to investigate the life table and predatory capacity parameters (numerical and functional responses) of the predator mite in 2020-2021 years. A second aim of the thesis is to monitor pest and predator populations after the release of N. californicus (predator:prey; 1:20) against artificially infested A. lycopersici in the tomato cultivars in 2021 during summer-autumn season in greenhouse conditions. As a result of N. californicus feeds on A. lycopersici, eggs of the predator hatched in 1,15-1,43 days in different tomato cultivars, 74-97% of the eggs laid in an average of 5,96-6,27 days are mature. Neoseiulus californicus lay a total of 2,17-7,73 eggs per female. Its lifetable parameters [the net reproductive rate (R0), the intrinsic rate of natural increase (rm), the finite rate of increase (λ), and the mean generation time (T0) varied between 1,91-9,71; 0,043-0,136; 1,04-1,15; 15,09-16,77, respectively. Additionaly, its functional response was determined to be Type II. After four releases with an interval of 15 days, the population of A. lycopersici was found to be significantly lower in the N. californicus released plots compared with the control plots (no release). The highest A. lycopersici population in the control plots was seen in mid-June and mid-September, while N. californicus was seen only in mid-June in the released plots. In addition, the highest N. californicus populations were determined from mid to late September. These results showed that N. californicus suppressed the A. lycopersici population after consecutive releases. Türkiye Tohum Gen Bankası Bursa Tohum Altın Tohumculuk

Domates (Solanum lycopersicum L.) bitkisi anavatanı Güney Amerika’nın batı kıyıları olan Solanaceae familyası türlerinden biridir. Sebze üretimi ve tüketimi içerisinde hem ülkemizde hem de dünya genelinde en çok üretilen ve tüketilen bitkiler arasında yer almaktadır. Domatesin pas akarına karşı toleransını arttıracak (zararın azalması ve hızlıca iyileşmesi ile bitki gelişimini teşvik etme gibi) alternatif çözümlere ihtiyaç duyulmaktadır. Bu çalışmayla birlikte, kontrollü koşullarda domates pas akarı bulaştırılan domates fidelerinde sadece üridin veya sadece akarisitlerin (abamectin, acequinocyl, pyridaben, spiromesifen) yarı dozlarının uygulaması ila bunların kombinasyonlarının akar zararına olan etkilerinin belirlenmesi amaçlanmıştır. Literatür taraması yapıldığında bu konuyla ilgili herhangi bir araştırmanın mevcut olmadığı gözlemlenmiştir. Denemede akarisit uygulanan kombinasyonlarda abamectin 0,25 mg/L, acequinocyl 62,5 mg/L, pyridaben 15 mg/L ve spiromesifen 25 mg/L konsantrasyonları kullanılmıştır. Bitkilerde büyüme oranı, klorofil miktarı, yaprak oransal su kapsamı ve turgor kaybı gibi fizyolojik parametreler ölçülmüştür. Bununla birlikte MDA, glutatyon ve askorbik asit miktarı ile antioksidatif savunma sistemine ait bazı enzimlerin CAT, APOX ve SOD aktivitesindeki değişimler de incelenmiştir. Çalışmada yapılan analizler sonucunda genel olarak tüm parametreler p

Background The tomato russet mite (TRM), Aculops lycopersici, and powdery mildew (PM), Oidium neolycopersici, are two major problems in tomato cultivation for which no effective biocontrol solutions exist to date. In a greenhouse compartment, we investigated the potential of preventatively establishing the iolinid omnivorous mite Pronematus ubiquitus on potted tomato plants to control both pest and pathogen simultaneously. Results Using Typha pollen, P. ubiquitus established well on tomato plants, with numbers reaching up to 250 motiles per tomato leaflet. The built-up population was capable of controlling subsequent infestations with both TRM and PM. This represents the first report of an arthropod protecting a crop against pests as well as disease. Conclusion The implementation of P. ubiquitus in tomato crops could be a real game-changer as it eliminates the need for repeated pesticide use or sulphur applications. The finding that arthropods can effectively control diseases opens up new opportunities for biological crop protection.

The conservation status of an ecosystem is checked by studying the composition and diversity of the organisms that interact in trophic chains. The aim of this study was to evaluate the biodiversity of mites associated to Capsicum annuum L. var glabriusculum (Solanaceae) at three sampling sites corresponding to two Protected Natural Areas (PNA) in Tamaulipas state, Mexico. Samplings were carried out in “Cañón de la Peregrina” and “Altas Cumbres” situated in the PNA "Altas Cumbres" and “Ojo de Agua”, located in the "El Cielo" Biosphere Reserve. Mite diversity was H = 1.09 ± 0.14 in Ojo de Agua, and it was H = 1.08 ± 0.08 and H = 1.11 ± 0.06 in Altas Cumbres and Cañón de la Peregrina, respectively. A total of 47 species were identified belonging to 35 genera of 18 families associated to C. annuum L. var glabriusculum in Mexico. Predatory mite richness was higher than that of generalist and phytophagous mites (31, 11 and 5 species, respectively) for the two ANP. The similarity index of Jaccard between OA–AC (IJ = 0.257; P < 0.05), CP–AC (IJ = 0.293; P < 0.05) and AC–CP (IJ = 0.324; P < 0.05) was low. Pseudopronematalus sp. 4 (Iolinidae) was predatory mite most abundant in both ANP (Pi = 9.311); followed by Metaseiulus (Metaseiulus) negundinis (Denmark) (Phytoseiidae) only for ANP “Altas Cumbres” (Pi = 1.004). While for phytophagus mite, Aculops lycopersici (Tryon) (Eriophyidae) and Tetranychus merganser Boudreaux (Tetranychidae) presented the highest abundances in all sites (Pi = 79.919 and 5.142, respectively). The high number of mites species associated to chile piquín suggests stability in the PNA despite anthropogenic activities, and that the PNA works as a mite reservoir.

Aculops lycopersici (Massee) causes plant desiccation and severe damage to tomato (Lycopersicon esculentum Mill) fruit, resulting in serious economic loss. The objective of the study was to determine the incidence of damage to fruit by A. lycopersici. Three varieties of tomato (SUN 7705, CID, and V305 F1) were used. Variety V305 F1 had the greatest index of damaged fruit (1.6852a), lowest index of useful fruit, (2.1878a) and least average weight per fruit (302.97a) of the three varieties. CID was least affected. The middle stratum had the greatest index of damaged fruit (2.3070a), lowest index of useful fruit, (1.5660b), and least average weight per fruit (254.89b) of the three strata. The lower stratum was least affected.

Over the last decade, the tomato russet mite, Aculops lycopersici, has become a major pest in tomato crops worldwide, both in open-field and protected cultivation. Its minute size of 150 to 200 μm complicates early detection and monitoring in tomato crops. Passive dispersal occurs via air currents, crop management practices and commercial trade. Chemical control of Aculops lycopersici is difficult. Altered product use from broad spectrum pesticides towards selective acaricides, to meet integrated pest management (IPM) standards, has created better conditions for the rapid expansion of this specialized eriophyid mite. Moreover, practical implementation of promising natural enemies is challenging due to the complexity of biological control in tomato crops. Trichomes on tomato negatively affect arthropod natural enemies, but provide a refuge for the tomato russet mite. Despite the cosmopolitan nature of Aculops lycopersici, knowledge associated with IPM is limited and fragmented. This review describes fundamental biological data on Aculops lycopersici from the last 20 years and novel developments in the field of prevention, monitoring, chemical and biological control. The recent analysis of the genome sequence will be helpful in the development of a sustainable control strategy for Aculops lycopersici. © 2021 Society of Chemical Industry.

Neoseiulus Hughes is one of the most diverse genus of Phytoseiidae, with approximately 400 described species. Among them, Neoseiulus tunus (De Leon) is very frequent and abundant in the Neotropical region. Although considerable amount of data about morphological variation of phytoseiid mites are available, the possible causes of intraspecific variations are still poorly understood, being diet and feeding habit usually reported as the main drivers. The present study investigated the influence of three different diets on morphological traits of taxonomic interest of N. tunus, aiming to verify whether diet is a determinant factor in the morphological pattern of this species and which structures are most affected by them. Our results show that based on the diet treatment, populations of N. tunus may be differentiated based on the size of morphological traits. All treatments differ from stock population and among them, except between populations feeding with Aculops lycopersici (Massee) (Eriophyidae) and Tetranychus urticae (Kock) (Tetranychidae). The widest range occurred on the dorsal setae, macrosetae of leg IV, width of the dorsal shield, distance between the bases of the genital’s setae and posterior width of the ventrianal shield. Most of the dorsal setae responded to the treatment with significant variation, being the longest lengths observed when the A. lycopersici was offered as diet. Considering the other two diets, the variation does not present a clear increasing or reducing pattern., Acarologia, 61, 486-496

The tomato russet mite, Aculops lycopersici, is among the smallest animals on earth. It is a worldwide pest on tomato and can potently suppress the host’s natural resistance. We sequenced its genome, the first of an eriophyoid, and explored whether there are genomic features associated with the mite’s minute size and lifestyle. At only 32.5 Mb, the genome is the smallest yet reported for any arthropod and, reminiscent of microbial eukaryotes, exceptionally streamlined. It has few transposable elements, tiny intergenic regions, and is remarkably intron-poor, as more than 80% of coding genes are intronless. Furthermore, in accordance with ecological specialization theory, this defense-suppressing herbivore has extremely reduced environmental response gene families such as those involved in chemoreception and detoxification. Other losses associate with this species’ highly derived body plan. Our findings accelerate the understanding of evolutionary forces underpinning metazoan life at the limits of small physical and genome size., eLife digest Arthropods are a group of invertebrates that include insects – such as flies or beetles – arachnids – like spiders or scorpions – and crustaceans – including shrimp and woodlice. One of the tiniest species of arthropods, measuring less than 0.2 millimeters, is the tomato russet mite Aculops lycopersici. This arachnid is among the smallest animals on Earth, even smaller than some single-celled organisms, and only has four legs, unlike other arachnids. It is a major pest on tomato plants, which are toxic to many other animals, and it feeds on the top cell layer of the stems and leaves. Tomato growers need a way to identify and treat tomato russet mite infestations, but this tiny species remains something of a mystery. One way to tackle this pest may be to take a closer look at its genome, as this could reveal what genes the mite uses to detoxify its diet. Examining the mite’s genome could also reveal information about how evolution handles creatures becoming smaller. An area of particular interest is the overall size of its genome. Not all of the DNA in a genome is part of genes that code for proteins; there are also sections of so-called ‘non-coding’ DNA. These sequences play important roles in controlling how and when cells use their genes. In the human genome, for example, just 1% of the DNA codes for protein. In fact, most human protein-coding genes are interrupted by sequences of non-coding DNA, called introns. Here, Greenhalgh, Dermauw et al. sequence the entire tomato russet mite genome and reveal that not only is the mite's body size miniature: these tiny animals have the smallest arthropod genome reported to date, almost a hundred times smaller than the human genome. Part of this genetic miniaturization seems to be down to massive loss of non-coding DNA. Around 40% of the mite genome codes for protein, and 80% of its protein coding genes contain no introns. The rest of the miniaturization involves loss of genes themselves. The mites have lost some of the genes that determine body structure, which could explain why they have fewer legs than other arachnids. Additionally, they only carry a small set of genes involved in sensing chemicals and clearing toxins, which could explain why they are mostly found on tomato plants. Greenhalgh, Dermauw et al.’s findings shed light on what may happen to the genome at the extremes of size evolution. Sequencing the genomes of other mites could reveal when in evolutionary history this genetic miniaturization occurred. Furthermore, a better understanding of the tomato russet mite genome could lead to the development of methods to detect the infestation of plants earlier and be highly beneficial for tomato agriculture.

Studies on the life history and life table parameters of Neoseiulus cucumeris Oudemans (Acari: Phytoseiidae) were carried out under laboratory conditions of 25 ± 1 °C and 65 ± 5% RH; 30 ± 1 °C and ...

The tomato russet mite (TRM), Aculops lycopersici, is a worldwide pest of cultivated tomatoes. Currently, no effective biological control agents are available on the market. Therefore, chemical spray applications are required. Fast and reliable detection, monitoring and evaluation of interventions are a challenge, slowing down the development of an appropriate integrated pest management (IPM) strategy. This study describes a binomial sampling plan with the aim to reduce the efforts and costs for an accurate monitoring of A. lycopersici. Sampling was performed by taking pictures of the upper leaf surface with a smartphone through an attached magnification lens. A binomial sampling plan was developed based on the linear relationship between ln(mean TRM densities) and ln(-ln(1-P-T), where P-T is the proportion of samples with more than T (tally threshold) mites. The minimum precision threshold of 0.30 was determined for the different models. A resampling for validation of sample plans (RVSP) programme with a fixed sample number was used for validation of the model on an independent data set. The binomial sampling plans were validated at tally thresholds of T = 9 and T = 15 with fixed sample sizes of 15, 20, 25 and 30. Precision levels were satisfying within a range of P-T-values from 0.29 to 0.97 for T = 15 at a fixed sample size of 20. This range was much smaller for T = 9, where the P-T-values range between 0.40 and 0.92 at the same sample size. A binomial sampling model with T = 9 with a fixed sample size of 15, which has the lowest time investment, is feasible for glasshouse tomato growers in practice. However, for the development of pest management programmes, a more intensive and more accurate binomial sampling plan with T = 15 and a sample size of minimum 20 is suggested.

This study aimed to determine the biological parameters of Neoseiulus tunus (De Leon, 1967) feeding on Aculops lycopersici (Massee, 1937). We conducted experiments to assess the predation rate of the former and its biological cycle when consuming A. lycopersici exclusively. Moreover, we assessed the preference of N. tunus for A. lycopersici concerning the pollen of Typha domingensis Pers. (Typhaceae) and Tetranychus urticae Koch, 1835, using free-choice tests. The obtained data indicates A. lycopersici is an appropriate prey to N. tunus, as it allows it to complete its development, reproduce and increase its population. We also noticed that this phytoseiid prefers A. lycopersici to the two other food sources. Though more robust studies will be needed, these preliminary results allow some inferences, such as N. tunus being a potential natural enemy of A. lycopersici.

The mite family Phytoseiidae contains predatory species used in biological control. However, among the 2,521 valid species, only a few are presently considered for pest management. The study focuses on a species, frequently observed in agrosystems, but whose biology is almost totally unknown: Typhlodromus (Anthoseius) recki. The objectives were to assess its distribution and to determine under laboratory conditions: (i) the development of three populations fed on three tomato pests (Tetranychus urticae, T. evansi, Aculops lycopersici), (ii) the dispersion along the tomato stem, and (iii) the dispersion from mint to infested tomato leaf discs. Based on its distribution, this species seems to be adapted to Mediterranean climate, and is preferentially found on Boraginaceae, Solanaceae, Asteraceae and Lamiaceae. Results show that T. (A.) recki is a generalist predator, with good performance regarding the number of prey consumed. Differences were observed between the populations considered; one population out of the three tested shows even a higher mean consumption of T. urticae than that recorded for Neoseiulus californicus and N. cucumeris. It is attracted by food source and is able to walk along the tomato stem. These results are encouraging enough to consider T. (A.) recki as a good natural enemy candidate for biological control (especially based on biodiversity conservation). Further experiments should be developed to test the predatory ability of this species at larger scale (entire tomato plants and tomato fields or greenhouses)., Acarologia, 60, 684-697

Symbiosis Acarid arthropods are common and economically important pests of crop plants. The tomato russet mite Aculops lycopersici is only 175 micrometers long but can potently suppress the host plant's natural resistance. It has a highly streamlined genome of 32.5 megabases, more closely resembling that of a protist than a metazoan. Greenhalgh et al. discovered that this mite leaves no room in its genome for hangers-on. It contains few transposons, has slimmed intergenic spaces to almost none, has almost done away with chemosensory apparatus and detox pathways, and has even reduced its number of legs from eight to four in the interests of economy. However, it has retained the capacity to suppress the tomato's jasmonic acid signaling pathway, which blocks the ability of the tomato host plant to produce defensive metabolites and proteins. However, the selective forces resulting in this genome diminution remain a puzzle—perhaps one is the poor nutritional value of tomato plants. eLife 9 , e56689 (2020).

[ES] El ácaro del bronceado del tomate, Aculops lycopersici (Tryon) (Acari: Eriophyidae) es una de las plagas más comunes del cultivo de tomate a escala mundial. Elimina el contenido celular de las hojas, tallos y frutos y provoca un bronceado de los tallos debido a la destrucción de tricomas. La detección y el monitoreo de A. lycopersici en plantas de tomate son difíciles debido a su tamaño microscópico. Los tratamientos químicos no suelen ser eficaces ya que cuando los agricultores observan los síntomas, la infestación ya está muy extendida. Esta tesis tiene como objetivo investigar en el laboratorio la capacidad de diferentes ácaros depredadores para controlar A. lycopersici. Además, se ha seleccionado un ácaro depredador adecuado para el control de la plaga: Pronematus ubiquitus (McGregor) (Acari: Tydeidae), y se han realizado ensayos adicionales de su potencial de depredación y de su capacidad de desarrollo sobre la plaga objetivo. Los resultados obtenidos revelaron que P. ubiquitus se alimentó de todos los estados de A. lycopersici en las hojas de tomate lo que sugiere un elevado potencial para suprimir las poblaciones de A. lycopersici. Por otra parte, al comparar el desarrollo y la reproducción de P. ubiquitus alimentado con Typha sp. y A. lycopersici se ha concluido que A. lycopersici es un alimento adecuado para P. ubiquitus. Se requieren más estudios para evaluar la eficacia depredadora de P. ubiquitus a diferentes temperaturas y para determinar la eficacia del ácaro depredador en cultivos de tomate en invernaderos., [EN] The tomato russet mite, Aculops lycopersici (Tryon) (Acari: Eriophyidae) is one of the most common pests of tomato crops on a worldwide scale. It removes cell contents from leaves, stems and fruits and results in bronzing of the stems due to destruction of trichomes. The detection and monitoring of A. lycopersici on tomato plants are hard due to their microscopic size. Chemical treatments have not been very successful at controlling this pest because, by the time farmers detect the symptoms of the damage, the infestation is already widespread. This thesis research aimed at investigating in the laboratory the ability of different predatory mites to prey on A. lycopersici. Further, a suitable predatory mite was selected through the screening, namely Pronematus ubiquitus (McGregor) (Acari: Tydeidae), and further analysis of its predation potential and studies of its development on the pest were conducted. The obtained results revealed that adult P. ubiquitus successfully preyed on all stages of A. lycopersici on tomato leaves and indicated its potential to suppress A. lycopersici populations. In addition, the comparison of successful development and reproduction of P. ubiquitus on Typha sp. pollen and on A. lycopersici showed that A. lycopersici alone is a suitable food source for P. ubiquitus. Further studies are required to assess predation at different temperature regimes by P. ubiquitus and to clarify the efficiency of the predatory mite on tomato plants in greenhouses., This thesis has been developed as a result of mobility stay funded by the Erasmus+ - KA1 Erasmus Mundus Joint Master Degrees Programme of the European Commission under the PLANT HEALTH Project and was supported in part by the project BALTO (LAtraject HBC.2017.0829) funded by VLAIO, Flanders, Belgium (coordinator Dr Raf De Vis).

Tomato plants are attacked by diverse herbivorous arthropods, including by cell-content-feeding mites, such as the extreme generalist Tetranychus urticae and specialists like Tetranychus evansi and Aculops lycopersici. Mite feeding induces plant defense responses that reduce mite performance. However, T. evansi and A. lycopersici suppress plant defenses via poorly understood mechanisms and, consequently, maintain a high performance on tomato. On a shared host, T. urticae can be facilitated by either of the specialist mites, likely due to the suppression of plant defenses. To better understand defense suppression and indirect plant-mediated interactions between herbivorous mites, we used gene-expression microarrays to analyze the transcriptomic changes in tomato after attack by either a single mite species (T. urticae, T. evansi, A. lycopersici) or two species simultaneously (T. urticae plus T. evansi or T. urticae plus A. lycopersici). Additionally, we assessed mite-induced changes in defense-associated phytohormones using LC-MS/MS. Compared to non-infested controls, jasmonates (JAs) and salicylate (SA) accumulated to higher amounts upon all mite-infestation treatments, but the response was attenuated after single infestations with defense-suppressors. Strikingly, whereas 8 to 10% of tomato genes were differentially expressed upon single infestations with T. urticae or A. lycopersici, respectively, only 0.1% was altered in T. evansi-infested plants. Transcriptome analysis of dual-infested leaves revealed that A. lycopersici primarily suppressed T. urticae-induced JA defenses, while T. evansi dampened T. urticae-triggered host responses on a transcriptome-wide scale. The latter suggests that T. evansi not solely down-regulates plant gene expression, but rather directs it back towards housekeeping levels. Our results provide valuable new insights into the mechanisms underlying host defense suppression and the plant-mediated facilitation of competing herbivores

Trichome-mediated defence in wild and cultivated tomato cultivars has been extensively studied against some mite species for several decades. Previous studies have shown that this mechanism negatively affects phytophagous mites and their predators. To better explain the tritrophic relationship of tomatoes, the interactions between population densities of the tomato rust mite, Aculops lycopersici (Massee) (Acari: Eriophyidae), and its predators on the tomato cultivars, namely, Dora, Etna, Grande, H2274, Jana and M1103, and the trichome densities of these cultivars were investigated in both a climatic room and an organic tomato field from 2014-2015. Under both controlled and field conditions, the A. lycopersici population density was significantly higher in the stake tomato cultivars, Jana and Etna, than in other tomato cultivars. When the tomato rust mite’s population density was the highest during mid-August and mid-September in the tomato field, the population density of the predator species, Tydeus kochi Oudemans (Tydeidae), showed a similar population pattern and significant positive correlation with the A. lycopersici density. However, density of this predator mite was significantly lower than that of A. lycopersici over the entire season. Remarkably, the glandular trichome type VI density was significantly higher in the stake cultivars than other cultivars. In contrast, significantly fewer glandular trichomes were found in the indeterminate tomato cultivars, Grande and H2274, which had fewer tomato rust mites and larger tydeid mite predator densities. These results support the hypothesis that trichomes provide excellent shelter for tomato rust mites and are obstacles for its predator mites. However, the population density of the insect predator, Macrolophus sp., was not affected by the trichome density or tomato cultivar, but its population density was not significantly correlated with that of the A. lycopersici population.

Climate change is expected to bring longer periods of drought and this may affect the plant’s ability to resist pests. We assessed if water deficit affects the tomato russet mite (TRM; Aculops lycopersici), a key tomato-pest. TRM thrives on tomato by suppressing the plant’s jamonate defenses while these defenses typically are modulated by drought stress. We observed that the TRM population grows faster and causes more damage on drought-stressed plants. To explain this observation we measured several nutrients, phytohormones, defense-gene expression and the activity of defensive proteins in plants with or without drought stress or TRM. TRM increased the levels of total protein and several free amino acids. It also promoted the SA-response and upregulated the accumulation of jasmonates but down-regulated the downstream marker genes while promoting the activity of cysteine—but not serine—protease inhibitors, polyphenol oxidase and of peroxidase (POD). Drought stress, in turn, retained the down regulation of JA-marker genes and reduced the activity of serine protease inhibitors and POD, and altered the levels of some free-amino acids. When combined, drought stress antagonized the accumulation of POD and JA by TRM and synergized accumulation of free sugars and SA. Our data show that drought stress interacts with pest-induced primary and secondary metabolic changes and promotes pest performance. Electronic supplementary material The online version of this article (10.1007/s10493-017-0200-4) contains supplementary material, which is available to authorized users.

Mites of family Stigmaeidae are potential predators of various species of phytophagous mites through the world.The present study was conducted in Acarology Research Laboratory Plant Protection Research Institute, Dokki, Egypt. The aim of this work was to study the effect of different prey species on the biology of stigmaeid mite, Agistemus vulgaris Soliman and Gomaa. The results showed that A.vulgaris completed its life cycle in 12.56 days when fed on Tetranychus urticae Koch as compared to 12.09 and 10.75 days when fed on Oligonychus sayedi Zaher, Gomaa & El-Enany and Aculops lycopersici Massee, respectively. The maximum average fecundity (53.75 eggs/female) was recorded after feeding on O. sayedi where as after feeding on T. urticae and A. lycopersici , it was 28.43 and 21.93, respectively. Predatory mite has better life table parameters in comparison with the other prey mites. The biological aspects of the predator was as follow, Mean generation time (T) averaged 18.63, 19.18 and 15.34 days, respectively; Net reproductive rate (Ro) averaged 12.82, 24.38 and 9.81; intrinsic rate of natural increase (rm) was 0.13, 0.16 and 0.14; finite rate of increase (λ) averaged 1.14, 1.18 and 1.16 when the mite fed on immature stages of T. urticae, O. sayedi and A. lycopersici, respectively. A. vulgaris is considered a promising biological control agent against phytophagous mites.

This study is conducted to develop a new method of early occurrence monitoring for Aculops lycopersici Massee (Acari: Eriophyidae), a major pest in tomato. A. lycopersici causes damage to plants such as curling of leaflet edges, followed by leaflet bronzing. As feeding continues by the mites, the plant takes on a russeted, wilted appearance, eventually culminating in leaflet desiccation and finally plant death. Fruit damages in tomato were shown when the density of mites was very high. Also, A. lycopersici caused more damage to unripe fruits than ripe fruits. The time taken to detect A. lycopersici on green label sticker was 7.0 seconds, the shortest. Blue, orange and white label stickers took 17.1, 19.8 and 12.3 seconds respectively. The permeable microscope with side illumination was useful in observing A. lycopersici on label stickers. A. lycopersici began to occur in late-April and the density of the mites increased rapidly after mid-May. The density peaked in mid to late-June, and decreased after late-June. A. lycopersici was observed on lower stems 20 days after the release of mites and observed on higher stems 60 days after. The peaked densities were observed on stems 40 and 60 days after and on leaf 80 days after. The label sticker is enough to monitor early occurrence of A. lycopersici in tomato cultivation facilities.

Experiments were conducted at Faculty of Agriculture farm Shebin Elkom and laboratory of Economic Entomology and Agricultural Zoology Department to study the eriophyid mites associated with three vegetable plants, five fruit trees, and two ornamental plants during the period from 2013/2015. Incidence studies indicated that 11 species of eriophyid mites belonging to 7 Genera was collected. Five plant extracts were chosen to determine their effect on Aculops lycopersici mite, after one week the redaction percentages were the highest when cayenne pepper and garlic used 98, 91 % while this percentage approximately ranged between 85, 88 % for other plant extracts, three weeks after application the reduction percentages were 100% in all plant extracts treatment except thyme record 98%. Ten chemical compounds as pesticides were experimented to show their effect on Aculops lycopersici. One day after application Sino S recorded the highest reeducation percentage 97% followed by Citrogard and Dumber 90%, while the lowest reduction percentages ware recorded by Vermex and Arrow 43, 46 %. Also, studied effect of some control methods against eriophyid mites on some morphological characters of tomato plants. It was observed that plant length increase in all treatments than untreated plants, increase percentage were 88.6, 89.7 % for Acari stop and high point treatment, while it was 88.4 , 90.9% in Cayenne pepper and Garlic three weeks after application. Biology of eriophyid mite Aceria dioscoridis reared in laboratory under 28± 2 C and 75± 5% R. H. the mean of incubation period was 1.75± 0.32 days, 72% from eggs was hatched to active larvae. Some biological aspects of predatory mite were studies when used Aceria dioscoridis ,Cisabroptus Kenyaeas prey, the incubation period of predator egg was 2.44± 0.61days for female, while it was 2.42± 0.51days for male. The life cycle of the predatory mite ranged from 8:12 days for female and 7: 12 for male.

Development, oviposition, and survival of a commercially available predatory mite, Amblyseius swirskii (Athias-Henriot), were investigated to determine the life history parameters when they consumed a diet of cattail ( Typha latifolia L.) pollen or tomato russet mites ( Aculops lycopersici [Massee]) at 25 ± 0.5 °C and 70 ± 10% RH. Both diets were favorable for development, oviposition, and survival of A. swirskii . Amblyseius swirskii reared on mite prey showed improved performance as compared to pollen. Females laid a total of 26.8 and 38.1 eggs on the pollen and mite diets, respectively. The mortality of female A. swirskii was very low during the first 20 days on both diets, and the cumulative Weibull models that were used to describe age-specific survival and fecundity of female showed a good fit to the data. The net reproductive rate ( R 0 ), intrinsic rate of increase ( r m ), and finite rate of increase ( λ ) of A. swirskii were higher on russet mites than when fed on the pollen diet due to their shorter immature development period and higher oviposition rate. The intrinsic rate of increase ( r m ) of the predatory mite was 0.185 and 0.201 on the pollen and mite diet, respectively. The mean generation time ( T ) and the population doubling time ( D t ) were not significantly different for A. swirskii on the two diets. Our results provide life history information for a commercially available A. swirskii using two favorable diets and can be used to compare population growth under other diet sources.

Predation, development, and oviposition experiments were conducted to evaluate Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae) as a potential biological control agent for tomato russet mite, Aculops lycopersici (Massee) (Acari: Eriophyidae), which can be a serious pest of greenhouse tomatoes. Results showed that A, swirskii attacked all developmental stages of A. lycopersici and had a type II functional response at the prey densities tested. The attack rate and handling time estimates from the random predator equation were 0.1289/h and 0.2320 h, respectively, indicating that A. swirskii can consume 103.4 individuals per day. Predation rates of A. swirskii on A. lycopersici in the presence of alternative food sources such as pollen, first-instar thrips, or whitefly eggs were 74, 56, and 76%, respectively, compared with the predation rate on A. lycopersici alone. A. swirskii successfully completed their life cycle on either A. lycopersici or cattail (Typha latifolia L.) pollen. At 25°C and 70% RH, developmental time of female A. swirskii fed on A. lycopersici or on cattail pollen was 4.97 and 6.16 d, respectively, For the first 10 d after molting to the adult stage, A. swirskii fed on A. lycopersici had higher daily oviposition rate (2.0 eggs per day) than on pollen (1.5 eggs per day). From this laboratory study, it can be concluded that A. swirskii has promising traits as a predator against A. lycopersici and that their populations can be maintained using alternative food sources such as cattail pollen. We suggest that the effectiveness of A. swirskii against A. lycopersici under field conditions needs next to be investigated.

Koprivina grinja Tetranychus urticae (Koch) i hrđasta grinja rajčice Aculops lycopersici (Masse) kozmopolitski su štetnici. Izraziti su polifagi i osim rajčice napadaju i brojne druge vrste kultiviranoga i samonikloga bilja. U vrlo kratkom vremenu mogu pričiniti velike štete stoga je potrebno provoditi niz različitih mjera koje uključuju sve raspoložive nepesticidne metode, ali i kemijsko suzbijanje. Bez kontinuiranog monitoringa na prisutnost grinja, ne može se na vrijeme zaštiti nasad od tih štetnika koji mogu uzrokovati velike štete., Twospotted spider mite Tetranychus urticae (Koch) and tomato russet mite Aculops lycopersici (Masse) are cosmopolitan pests. Both species are extremely polyphagous and have been reported on numerous host plants, including tomato. In a very short period of time can cause a lot of damage so it is necessary to implement a variety of measures, including chemical control. Without continuous monitoring, it is not possible to protect tomato from mites, which can cause great damage.