Predatory Phytoseiid Mites Research Articles

Comparative Toxicity of Certain Acaricides against Tetranychus urticae Koch and their Side Effects on Phytoseiulus persimilis A.-H. (Acari: Tetranychidae: Phytoseiidae)

The acaricidal activity using the recommended concentrations of the novel compound cyflumetofen 24% SC as compared with bifenazate 48% SC and abamectine 1.8% EC was determined against the two-spotted spider mite, Tetranychus urticae Koch under greenhouse conditions at Faculty of Agriculture, Cairo University during 2017-2018. Their side effect on the predatory phytoseiid mite, Phytoseiulus persimilis Athias-Henriot was also investigated. Average number of mite mortality in the two seasons showed that abamectin was more toxic to predatory mite than other tested acaricides, while cyflumetofen was more toxic to spider mites T. urticae and followed by abamectin and bifenazate. Field trials proved that cyflumetofen was not as harmful as other compounds. Therefore, life-table parameters of both T. urticae and P. persimilis treated with LC50 of cyflumetofen were investigated in laboratory to know more knowledge about the population growth of mite pest and its natural enemy under stressful of treatment. Cyflumetofen prolongedthe mean generation time, doubling time while it decreased fecundity as represented by female proportion in the generation, net reproductive rate, intrinsic rate of increase, finite rate of increase and gross reproductive rate of both mite species. Cyflumetofen showed considerable negative effects on T. urticae life-tables but it had moderate or low effects on P. persimilis. It is recommended to use the novel acaricide, cyflumetofen in IPM programs of plants feeding spider mites.

Composition, repellent and fumigant toxicity of Mentha longifolia essential oil on Tetranychus urticae and three predatory mites of the family phytoseiidae (Acari: Tetranychidae: Phytoseiidae)

The chemical composition of essential oil extracted from leaves of the medicinal plant Mentha longifolia (L.) Huds growing in Egypt, were determined through Gas Chromatography/Mass Spectrometry ( GC/MS). The analyses revealed that the major component of M. longifolia was Monterpene ketone (piperitone oxide). Mentha longifolia was potent for the pest Tetranychus urticae Koch with a significant increase in repellency. In addition, it exhibited strong oviposition deterrence to the pest based on a 99.4% reduction of the total number of eggs on leaf discs treated with the oil. The LC50 values of M. longifolia against eggs, nymphs and females of T. urticae by fumigant application, were 2.95, 3.47, 3.74 μL / L, while the LC90 values were 8.99, 9.41, 11.01 μL/ L, respectively. The toxicity of M. longifolia oil by fumigant application to females and eggs of 3 predatory phytoseiid mites was tested. Neoseiulus californicus (McGregor) is extremely insusceptible to M. longifolia oil than the pest T. urticae and both phytoseiid mites, Neoseiuls barkeri (Hughes) and Typhlodromips swirskii (Athias Henriot) under laboratory conditions. When both stages of tested predatory mites, exposed to fumigant of LC50 and LC90 μL/L values reported on T. urticae, female’s mortality of N. californicus was lesser than that reported on N. barkeri and T. swirskii. These show that the fumigant toxicity of M. longifolia oil has the highest lethal activity to the pest T. urticae and the least to the predatory mite N. californicus. Results indicated that the mode of delivery of the essential oil was largely a result of action in the vapor phase via respiratory system. Data was suggested that M. longifolia oil have the potential agent to be used in the maintainable management of T. urticae combined with N. californicus.

To the species structure of predatory phytoseiid mites (Parasitiformes, Phytoseiidae) of state reserve “Elanetskyi Step”

As material for this work the gatherings of the author executed in 2016 year. On 43 species of plants 85 samples in which 249 copies of phytoseiid mites are revealed are taken. For the statistical analysis used an occurrence index (P1, %) and an index of domination of Paliya-Kovnatski (Di). Species structure of predatory phytoseiid mites (Parasitiformes: Phytoseiidae) in plant associations of state reserve "Elanetskyi step" (Mykolaiv region, Ukraine) were studied at the first time. 21 species of 7 genera of the family are detected (A. andersoni, A. herbarius, A. maior, N. marginatus, N. reductus, N. tauricus, E. finlandicus, D. echinus, T. tiliarum, P. intermixtus, P. soleiger, A. caudiglans, A. rapida, A. pirianykae, A. recki, A. verrucosa, A. spectata, T. cotoneastri, T. laurae, T. tiliae). Frequency of occurrence and fidelity to different types of plant communities for each species of mites were determined. Amlydromella (s. str.) recki, the most common species, was with occurrence index 35.3%. The species Amblydromella (s. str.) rapida, Amblydromella (Litoseia) spectata, and Paraseiulus intermixtus were the rare species (one specimen of each species was presented at collections). Amblydromella (s. str.) recki was the dominant in the complex of plant-feeding predatory mites. Three species, A. pirianykae, A. andersoni and E. finlandicus, were the subdominants. Typhlodromus cotoneastri was the subdominant of the first order. The remaining 16 species were the secondary members of the complex.

A Pollen Diet Confers Ultraviolet-B Resistance in Phytoseiid Mites by Providing Antioxidants

Many plant-dwelling mites including phytophagous spider mites and predacious phytoseiid mites suffer lethal deleterious effects from solar ultraviolet-B (UVB; 280–315 nm wavelength) radiation. Phytoseiid species also often feed on pollen as an alternative food source. As pollen is frequently exposed to solar radiation, it is likely to contain compounds that protect germ cells from UVB radiation and radiant heat. If phytoseiid mites can obtain these protective compounds, pollen feeding may play a role in their adaptation to UVB. In this study, we compared the potential protective effects of tea pollen, peach pollen, and Tetranychus urticae mites as food items in Neoseiulus californicus. Egg hatchability and adult female survival after UVB irradiation were higher in pollen-fed than mite-fed N. californicus. The major protective effects of peach pollen and tea pollen were UVB shielding effects and antioxidant capacity, respectively, and these were derived from distinctive antioxidant components. The major antioxidant in peach pollen was tri-p-coumaroylspermidine, although its antioxidant capacity was relatively low; instead, it effectively absorbed UVB radiation. By contrast, the major antioxidants of tea pollen were catechin and epicatechin 3-gallate, which had high antioxidant capacities. Our results indicate that the protective antioxidant components in pollen improved UVB resistance in N. californicus, contributing to their adaptation to solar radiation.

Life tables of the predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae) on two pest mites as prey, Aculops lycopersici and Tetranychus urticae

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 60 ± 5% RH; 35 ± 1 °C and 55 ± 5% RH. As prey, immature stages of tetranychid spider mite T. urticae Koch (Acari: Tetranychidae) and the moving stages of the Tomato Russet Mite A. lycopersici (Massee) (Acari: Eriophyideae) were selected. The predatory phytoseiid mite, Neoseiulus cucumeris (Oudemans) was able to develop successfully from egg to adult stage through the entire life history on both preys. The higher of different temperatures and relative humidities shortened the development and increased reproduction and prey consumption and vice versa. The maximum reproduction (3.91, and 3.09 eggs/♀/day) was recorded at 35 °C and 65% RH, while the minimum (2.12, and 1.90 eggs/♀/day) was at 25 ± 1 °C and 55 ± 5% RH. when N. cucumeris fed on A. lycopersici and T. urticae, respectively. The reproductive rate on eriophyid was significantly higher than previously recorded on tetranychid. Life table parameters indicated that feeding of phytoseiid mite N. cucumeris on tomato russet mite A. lycopersici led to the highest reproduction rate (rm = 0.268, 0.232 and 0.211 females/female/day), while feeding on T.urticae gave the lowest reproduction rate (rm = 0.159, 0.143 and 0.131) at 35 °C and 55% RH, 30 °C and 60% RH and 25 °C and 65% RH, respectively. The population of N. cucumeris multiplied (36.81, 28.71 and 20.47) and (24.60, 19.58 and 14.62 times) in a generation time of (20.10, 23.20 and 25.14) and (22.35, 25.36 and 27.79 days) when a predator fed on A. lycopersici and T. urticae at the same temperature above mentioned, respectively. These results suggest that the two mites, particularly A. lycopersici, proved to be suitable prey for N.cucumeris, as a facultative predator.

Reciprocal intraguild predation between Neoseiulus barkeri and Amblyseius swirskii (Mesostigmata: Phytoseiidae): Does experience affect anti-intraguild predation behaviors?

In order to increase their inclusive fitness, animals predominantly probe their changing environment for predation cues to adopt appropriate antipredator strategies and decrease the costs of defensive behavior. Intraguild predation (IGP) occurs when a predator kills and consumes individuals of another predator which is its competitor for a shared prey. IGP is prevalent among predatory mites of the family Phytoseiidae which are used as biological control agents of agricultural pests worldwide. Phytoseiid mite mothers usually display antipredator behaviors to avoid or reduce IGP risk of their juveniles. When facing a novel IGP risk, experience may enable the mothers to display more efficient antipredator responses. We studied the effect of experience on reciprocal antipredator behaviors of an indigenous predatory phytoseiid mite, i.e., Neoseiulus barkeri Hughes, and an exotic one, i.e., Amblyseius swirskii Athias-Henriot, as biological control candidates for integrated pest management strategies in Iran. First, we determined the occurrence of IGP and mutual risk of the predators within the guild; IGP occurred reciprocally and A. swirskii was the stronger IG predator. Second, in choice situations between a patch with only shared prey and a patch with shared prey plus IGP risk cues, we scrutinized patch choice, oviposition site selection and ability to counterattack by females of each species that had either experienced the IGP risk or not. The experience did not affect patch choice and oviposition behaviors of the species whereas it elicited an increase in their predation on IG predator juveniles. We suggest that the presence of IG predator juveniles and cues may not significantly modify the distribution of the IG prey species. The reinforced counterattack behavior in experienced females showed that both species were able to tune their antipredator behavior after exposure to IG predators. Consequences of the antipredator behaviors in experienced IG prey females on distribution and possibilities of the coexistence of the study species are discussed.

Особливості структури комплексів фітосеїдних кліщів в рослинних асоціаціях міст

20 species of 10 genera of mites of this family Phytoseiidae were found while studying a species composition on the plants of urban environment Amblyseius andersoni Chant, 1957; Amblyseius rademacheri Dosse, 1958; Neosiulus herbarius Wainstein, 1960; Neoseiulus reductus Wainstein, 1962; Euseius finlandicus, Oudemans, 1915; Kampimodromys aberrans Ouderman, 1930; Dubininellus echinus Wainstein et Arutunjan, 1970; Dubininellus juvenis Wainstein et Arutunjan, 1970; Typhlodromus cotoneastri Wainstein, 1961; Typhlodromus laurae Arutunjan, 1974; Typhloctonus aceri Collyer, 1957; Typhloctonus tiliarum Oudemans, 1930; Paraseiulus incognitus Wainstein et Arutunjan, 1967; Paraseiulus soleiger Ribaga, 1902; Amblydromella (s.str.) caudiglans Scheuten,1959; Amblydromella (s.str.) pirianykae Wainstein, 1972; Amblydromella (s.str.) rhenana Oudemans, 1905; Amblydromella clavata Wainstein, 1972; Amblydromella (Aphanoseius) verrucosa Wainstein, 1972; Galendromus longipilus Nesbitt, 1951. The peculiarities of their spreading in plant associations of Kyiv city, Uman city, Vasylkiv town, Brovary town (Ukraine) which differed from each other by various characteristics (population, area, urbanization degree, etc.) were determined. Total 68 species of plants were examined in the territory of Kyiv city where there were 40 species of trees and shrubs (including 2 types of conifers) and 28 species of herbaceous plants; 16 species of 10 genera of predacious phytoseiid mites were found. 14 species of 8 genera of mites were registered on 25 plant species in the territory of Brovary town (16 species of tree-and-shrub and 9 species of herbaceous plants) in the result of processing of collected materials. 10 species of 7 genera were identified while studying the current state of species diversity of predacious mites of Phytoseiidae family on 26 species of trees and shrubs of green urban plantations within Vasylkiv town. 12 species of 7 genera of Phytoseiidae mites were identified in the result of study of urban plantations in Uman city. Common species at studied areas were the following seven species: A. andersoni, A. rademacheri, E. finlandicus, K. aberrans, T. laurae, T. aceri, T. tiliarum. During the researches the domination index (Di). It was found that spreading of mites was different. Dominant species, subdominant species, subdominant of first order and minor members of species complexes were revealed while analysed the species structure of predacious phytoseiidae mites. E. finlandicus was the dominant in all research plots: Kyiv (Di = 51.63 %), Uman (Di = 60.32 %), Vasylkiv (Di = 15.65 %), Brovary (Di = 33.90 %). K. aberrans (Di = 15.52 %) and E. finlandicus was determined as dominant species n Vasylkiv town. K. aberrans (Di = 2.35 %) and T. aceri (Di = 1.30 %) had the status of subdominant species in research areas. We also have been studied the mite species diversity on the grass and shrubs. We studied the mites on the 93 species of plants where 55 were trees and shrubs (58.9 %) and 38 species were the herbaceous plants (41.1 %).

Peculiarities of Distribution of Two Amblydromella Species (Phytoseiidae, Parasitiformes) in the Zone of Their Natural Intergradation in the Eastern Ukraine

Abstract Distribution of two morphologically and ecologically related species of predatory phytoseiid mites of the genus Amblydromella (A. pirianykae and A. recki) in a zone of their natural intergradation (mountain ridge Donetsky Kriazh in the east of Ukraine) is studied for the first time. The list of plants populated by both predators is given. Consistent patterns of mite distribution on life forms of plants are determined biotopical fidelity on the basis of the coefficient. Very rarely, A. pirianykae and A. recki mites simultaneously populate the same plant organism (only 1.6 % of all samples) which can be attributed to the partially resolved antagonistic relationships. Th e basis of the antagonism is, in the first place, similarity of food preferences of the predators that, in principle, occupy the same ecological niche. Dramatic finale of this confrontation is the elimination of one of the species which has no distinct advantage in the specific conditions of a local microhabitat.

Synergism of Beauveria bassiana and Phytoseiulus persimilis in control of Tetranychus urticae on bean plants

Tetranychus urticae Koch (Acari: Tetranychidae) causes severe damage in both greenhouse and field crops. Previous studies have found that a phytoseiid predatory mite, Phytoseiulus persimilis Athias-Henriot, and an entomopathogenic fungus, Beauveria bassiana (Balsamo) Vuillemin, are both potential candidates for the control of this pest and have shown varying degrees of success. We assessed the compatibility of these two biological control agents for control of T. urticae on potted bean plants, examining the following treatments: i) a low release rate of P. persimilis (10 prey:1 predator), ii) a high release rate of P. persimilis (5:1), iii) a single application of B. bassiana (1 × 108 spore/ml), iv) a single application of B. bassiana after application of the low release rate of P. persimilis, and v) a non-treatment control (no application of either B. bassiana or P. persimilis). A single application of B. bassiana reduced the egg and adult populations of T. urticae initially, but mite populations rebounded again after few days. Phytoseiulus persimilis at the high release rate eliminated the pest population completely, while the low release rate failed to control spider mites. The combined application of B. bassiana and low release rate of P. persimilis also successfully controlled T. urticae population (p < 0.001), with lowest corrected leaf damage (1.5%).

Biological control of Echinothrips americanus by phytoseiid predatory mites and the effect of pollen as supplemental food

The poinsettia thrips, Echinothrips americanus Morgan, is an upcoming pest in greenhouse crops, causing serious damage in various vegetable and ornamental crops through extensive foliage feeding. We assessed which stages of E. americanus are attacked and killed by the phytoseiid predatory mites Amblyseius swirskii (Athias-Henriot), Amblydromalus limonicus (Garman and McGregor), Euseius gallicus Kreiter and Tixier and Euseius ovalis (Evans). Both the predation and oviposition rates were assessed in the laboratory to evaluate which mite species is potentially the most effective predator of E. americanus. In two greenhouse trials with non-flowering sweet pepper plants, we compared the efficacy of the predators E. gallicus and E. ovalis with A. swirskii and we assessed how this was affected by the application of cattail pollen. All stages of E. americanus, except adults, were consumed by all species of predatory mites. The highest predation and oviposition rates were recorded for A. limonicus followed by A. swirskii and E. ovalis when first and second larval stages were provided as prey, but E. ovalis appeared to be the best predator of thrips pupae. Euseius gallicus displayed very low predation and oviposition rates compared to the other species of predatory mites. Cattail pollen did not support the population growth of poinsettia thrips, but it strongly increased the predatory mite population densities, particularly those of E. ovalis. Both A. swirskii and E. ovalis significantly reduced thrips densities on plants. The application of pollen significantly enhanced the control of E. americanus by A. swirskii; this was not the case for E. ovalis. Euseius gallicus did not reduce densities of E. americanus on sweet pepper plants, not even at high densities in the presence of pollen.

Efficacy of two predatory mite species to control whiteflies infesting poinsettia plants compared to the standard parasitoid Encarsia formosa

The two predatory phytoseiid mite species Amblydromalus limonicus (Garman and McGregor) and Transeius montdorensis (Schicha) were tested as alternative for the control of the two whitefly species Trialeurodes vaporariorum (Westwood) and Bemisia tabaci (Gennadius). As standards the parasitoid wasp E. formosa was included as well as a chemical routine treatment. Efficacy of all beneficials to control T. vaporariorum was comparable to the chemical regime, and all treatments provided good pest control without significant differences. Shortly after release, individuals of both predatory mite species were found on nearly each plant but numbers decreased after three to four weeks. Hence, releases had to be repeated regularly. Control of B. tabaci was slightly less efficient. Efficacy of E. formosa and T. montdorensis was similar followed by A. limonicus with 20, 26 and 56 B. tabaci larvae remaining per plant, respectively. Although numbers of beneficials had been increased for control of B. tabaci numbers were still not high enough. However, results indicate that successful control is possible.

Predatory phytoseiid mites associated with cassava in Kenya, identification key and molecular diagnosis (Acari: Phytoseiidae)

The objective of this study was to carry out a large survey in order to characterize Phytoseiidae species diversity on cassava in Kenya. A total of 29 species from 10 genera were identified in diverse ecological zones in Kenya. The warm-to-hot low midlands of eastern and the warm-humid coastal strip yielded over 70 % of the species identified. The dominant species were Euseius fustis (Pritchard and Baker) and Typhlodromalus aripo De Leon present in 37 and 34 % of samples, respectively. Typhlodromalus aripo was found persistent in coastal, eastern and western regions of Kenya while E. fustis was present in all sampled localities of the country. In addition to morphological diagnosis, molecular sequences for DNA fragments 12S, CytB, COI and ITS, were obtained for T. aripo and E. fustis. Molecular diagnosis has revealed the unexpected presence of Neoseiulus idaeus Denmark and Muma and indicated its misidentification as Neoseiulus onzoi (Zannou, Moraes and Oliveira) in a previous survey carried out in Kenya. Molecular sequences herein obtained will help further diagnosis of phytoseiid species and complement the international reference databases needed to assist molecular identification of Phytoseiidae species.

Innate and acquired response of Neoseiulus barkeri and Neoseiulus californicus (Acari: Phytoseiidae) to spider mite induced plant volatiles

Predators may adjust their foraging behavior according to herbivore induced plant volatiles innately or through learning. Here, first we investigated whether the phytoseiid predatory mites, Neoseiulus californicus and N. barkeri were innately able to respond to odors related to Tetranychus urticae infested bean leaves. The naive predator females were reared on washed T. urticae as prey on filter paper with no experience of SIPV. The olfactory experiments showed that both N. barkeri and N. californicus significantly moved towards T. urticae infested bean leaves rather than clean air. Neoseiulus californicus significant preference of T. urticae infested bean leaves rather than clean tomato (as unfamiliar environment) confirmed the innate response in this species, while N. barkeri could not differentiate the latter odor sources so that its innate response considered weak. In a separate set of experiments, naive N. californicus females with no preference towards SIPV were experienced by receiving odors related to T. urticae infested bean leaves. The changed response (significant preference) of the experienced individuals showed the predator ability for acquired response. As the predator paired the odor with food absence/presence, associated learning was suggested as the mechanism. No acquired response was recorded for N. barkeri.

カブリダニに捕食されたハダニ卵齢が蛍光プライマーを用いた検出率に及ぼす影響

カブリダニに捕食されたハダニ卵齢が蛍光プライマーを用いた検出率に及ぼす影響

Biological control of thrips pests (Thysanoptera: Thripidae) in a commercial greenhouse in Hungary

AbstractPolyphagous thrips, like western flower thrips Frankliniella occidentalis and onion thrips Thrips tabaci, are major pests in various ornamental and vegetable crops in greenhouses throughout the world. In Hungary, both of these polyphagous thrips species frequently cause severe damage in many greenhouse crops, especially in commercial sweet pepper. Chemical control is not always feasible because of certain ecological characteristics of these thrips species. The commercially available phytoseiid predatory mites like Amblyseius swirskii and anthocorid flower bugs like Orius laevigatus are often used simultaneously for the biological control of severe thrips infestation in sweet pepper cultivation in Hungary. Our observations demonstrated that the polyphagous thrips assemblages were effectively controlled by the combined release of natural enemies, despite the fact that the establishment of O. laevigatus did not seem to be successful in the first year. Overall, the thrips population density remained below the economic threshold in both years. However, the low infestation level of thrips suggests that a single predator release strategy could be applied effectively and still maintain the thrips below the damage threshold in greenhouse sweet pepper.

Highly virulent Beauveria bassiana strains against the two-spotted spider mite, Tetranychus urticae, show no pathogenicity against five phytoseiid mite species.

Entomopathogenic fungi and predatory mites can independently contribute to suppressing the two-spotted spider mite, Tetranychus urticae Koch. It is important to assess the risk of possible fungal infections in predators when a combination of them are being considered as a tandem control strategy for suppressing T. urticae. The first part of this study tested 12 Beauveria bassiana isolates for virulence in T. urticae. Strains SCWJ-2, SDDZ-9, LNSZ-26, GZGY-1-3 and WLMQ-32 were found to be the most potent, causing 37.6-49.5% adult corrected mortality at a concentration of 1×107m/L conidia 4days post-treatment. The second part evaluated the pathogenicity of these five strains in five species of predatory phytoseiid mites. The bioassay results indicated that all adult predatory mite mortalities ranged from 7.5 to 9.1% 4days post-treatment. No viable fungal hyphae were found on predator cadavers. Observations with scanning electron microscopy revealed that conidia were attached to the cuticle of predatory mites within 2-12h after spraying with strain LNSZ-26, and had germinated within 24-36h. After 48h, conidia had gradually been shed from the mites, after none of the conidia had penetrated the cuticular surfaces. In contrast, the germinated conidia successfully penetrated the cuticle of T. urticae, and within 60h the fungus colonized the mite's body. Our study demonstrated that although several B. bassiana strains displayed a high virulence in T. urticae there was no evident pathogenicity to phytoseiid mites. These findings support the potential use of entomopathogenic fungus in combination with predatory mites in T. urticae control programs.

Genome Sequencing of the Phytoseiid Predatory Mite Metaseiulus occidentalis Reveals Completely Atomized Hox Genes and Superdynamic Intron Evolution.

Metaseiulus occidentalis is an eyeless phytoseiid predatory mite employed for the biological control of agricultural pests including spider mites. Despite appearances, these predator and prey mites are separated by some 400 Myr of evolution and radically different lifestyles. We present a 152-Mb draft assembly of the M. occidentalis genome: Larger than that of its favored prey, Tetranychus urticae, but considerably smaller than those of many other chelicerates, enabling an extremely contiguous and complete assembly to be built—the best arachnid to date. Aided by transcriptome data, genome annotation cataloged 18,338 protein-coding genes and identified large numbers of Helitron transposable elements. Comparisons with other arthropods revealed a particularly dynamic and turbulent genomic evolutionary history. Its genes exhibit elevated molecular evolution, with strikingly high numbers of intron gains and losses, in stark contrast to the deer tick Ixodes scapularis. Uniquely among examined arthropods, this predatory mite’s Hox genes are completely atomized, dispersed across the genome, and it encodes five copies of the normally single-copy RNA processing Dicer-2 gene. Examining gene families linked to characteristic biological traits of this tiny predator provides initial insights into processes of sex determination, development, immune defense, and how it detects, disables, and digests its prey. As the first reference genome for the Phytoseiidae, and for any species with the rare sex determination system of parahaploidy, the genome of the western orchard predatory mite improves genomic sampling of chelicerates and provides invaluable new resources for functional genomic analyses of this family of agriculturally important mites.

An astigmatid defence volatile against a phytoseiid mite

AbstractNumerous semiochemicals have been isolated from several species of astigmatid mites with various identified or unidentified functions. Alarm pheromonal activity is widespread with neryl formate and neral, being the most common compounds eliciting alarm response in conspecifics. The cosmopolitan astigmatid mite Suidasia medanensis (= S. pontifica) Oudemans (Acari: Suidasidae) has been reported to use neral as an alarm pheromone, but neral can also act as an allomone towards predators of oribatid mites. Suidasia medanensis can be utilised as a factitious prey for mass‐rearing of the phytoseiid predatory mite Amblyseius (= Typhlodromips) swirskii (Athias‐Henriot) (Acari: Phytoseiidae), which is used for biological control of insect and mite pests in protected crops. This study investigated the potential defence properties of the S. medanensis volatiles against A. swirskii, comparing the repellency to pollen‐reared (naïve) vs. S. medanensis‐reared (experienced) predators using a synthetic blend of the isomers neral and geranial (1:1) as a model compound. In a repellency bioassay, the synthetic blend elicited a significant repellence to A. swirskii with no difference between naïve and experienced predators. During capture success studies, S. medanensis under repeated attack could release sufficient quantities of the defence volatile to deter 1–5 attacks from A. swirskii, whereas hexane‐treated S. medanensis artificially depleted of volatiles were significantly more vulnerable to an attack. This is the first report of an astigmatid defence volatile with repellent activity to a phytoseiid mite and the starting point to understanding semiochemical interactions in any current or novel factitious predator‐prey mass‐rearing system.

Suitability of Corcyra cephalonica Eggs (Lepidoptera: Pyralidae) for the Development, Reproduction and Survival of Four Predatory Mites of the Family Phytoseiidae (Acari: Phytoseiidae)

The influence of rice moth, Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) eggs on the development, survival and reproduction of four predatory phytoseiid mites was studied under laboratory conditions. Amblyseius largoensis (Muma) successfully developed and reproduced on C. cephalonica eggs, while protonymphs of Neoseiulus barkeri (Hughes), Cydnoseius negevi (Swirski and Amitai) and Typhlodromips swirskii (Athias-Henriot) failed to develop beyond the protonymphal stage.

Arthropod ecosystem services in apple orchards and their economic benefits

Apple is grown as a long‐term perennial crop and orchards provide relatively stable ecological habitats. Only a small proportion of the diverse fauna of arthropods that can inhabit the orchard ecosystem are important pests, the majority of species being minor pests, beneficial or benign. In this paper, the interacting ecosystem services provided by five contrasting naturally occurring arthropod groups in cool temperate apple orchards are reviewed, and their economic benefits broadly quantified. These are:The roles of bees and other insects in apple pollination increasing yields and fruit quality, the economic value of which may be significantly underestimated. Naturally occurring, pesticide‐resistant phytoseiid predatory mites and their role in regulating phytophagous mites. They eliminate the need for 1–2 acaricide sprays per annum and the risk of acaricide resistance. The earwig Forficula auricularia L. and its role in regulating several important apple pests. There is great variability in populations between orchards for reasons not fully understood. It is estimated that F. auricularia reduces insecticide applications by 2–3 per annum and reduces pest damage. Mutualism between the common black ant Lasius niger (L.) and important pest aphids, the roles of competitors, natural and artificial food sources, and ant exclusion in disrupting mutualism which can foster biocontrol of aphids by generalist predators so greatly reducing the need for sprays. Beneficial epigeic arthropods and their role in predating the soil dwelling life stages of insect pests. These contribute to the control of pest populations although the level of suppression is not consistent depending on several ecological factors.