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Neoseiulus barkeri Hughes has been used to control several pests, including the red palm mite, Raoiella indica Hirst. However, in some situations, the exclusive use of biocontrol agents is not sufficient to prevent the damage caused by pests. In these scenarios, the integration of chemical and biological controls is desired. For that purpose, the determination of selective acaricides, avoiding or reducing deleterious effects on the biological control agent is desirable. This study evaluated the lethal and sublethal effects of acaricides (abamectin, azadirachtin, fenpyroximate and pyridaben) on the predatory mite N. barkeri. We investigated the toxicity and selectivity of the acaricides and the survival, fertility, egg viability and instantaneous growth rate (ri) of N. barkeri exposed to acaricides. Additionally, we classified the acaricides according to the scale proposed by the International Organization for Biological Control (IOBC). Among the acaricides evaluated, abamectin was selective for N. barkeri because the estimated lethal concentration (LC50) for N. barkeri was higher than that for R. indica. None of the acaricides affected predator survival curves. However, azadirachtin and fenpyroximate reduced the average predator survival time. Pyridaben was the only acaricide that reduced the fertility of N. barkeri females and, consequently, their instantaneous growth rate (ri). All the acaricides affected the viability of N. barkeri eggs. Pyridaben was classified as moderately harmful, whereas other acaricides were classified as harmless. [ABSTRACT FROM AUTHOR]

Pollen as one of the most important supplementary food benefits the generalist predators in many aspects. However, little is known about the performance of generalist predators with type IV lifestyle when they are reared continuously on prey supplemented with pollen for many generations. In this study, the life history traits of the predatory mites Euseius nicholsi (Ehara et Lee) (Acari: Phytoseiidae) were compared when two prey species, Tetranychus urticae Koch (Acari: Tetranychidae) and Eotetranychus kanktus Ehara (Acari: Tetranychidae) were offered with the presence/absence of camellia pollen. The results showed that the mixed diet of prey and pollen significantly improved the fitness of predatory mites. Predatory mites with pollen as supplementary food developed 1 day faster than their counterparts fed only with prey. They survived much longer and produced almost twice as many eggs as their counterparts. Nevertheless, these benefits were only evident in the first few generations and faded away from Generation 5. This study advanced our understanding by indicating that the beneficial effects of supplementary pollen decreased along with generations and clarifying that T. urticae was a more nutritious prey to E. nicholsi. [ABSTRACT FROM AUTHOR]

Banker plant systems can enhance biological control of arthropod pests in protected agriculture if they facilitate the persistence of beneficial organisms by providing them with persistent habitats or supplemental food such as pollen or nectar. Ornamental pepper banker plants infested with either the predatory phytoseiid mites Amblyseius swirskii (Athias‐Henriot) or Amblydromalus limonicus (Garman and McGregor) were tested under greenhouse conditions in Florida, USA, for management of the chilli thrips, Scirtothrips dorsalis Hood on Double Knock Out® roses. After two 6‐week studies, performed from October to December 2019 and 2020, both mite species reduced populations of S. dorsalis on roses to nearly undetectable levels (<1 thrips/leaf) compared with predator‐free controls. There was no difference in the mean number of thrips on leaves between the two mite species treatments. Lower S. dorsalis numbers observed on roses when mites were present led to significantly reduced foliar damage assessed as the degree of tissue scarring from S. dorsalis feeding compared with the control. This study may provide rose growers in Florida an alternative option for managing S. dorsalis populations on roses, a typically unsuitable plant for maintaining mite populations. [ABSTRACT FROM AUTHOR]

Cannibalism is a commonly found behaviour in the animal kingdom. The biggest concern of cannibalism is that it reduces the inclusive fitness of the cannibals by eliminating close relatives. Kin recognition is a strategy used by many cannibals to benefit from cannibalism without the cost of reducing their inclusive fitness by eating close relatives. Most members of the family Phytoseiidae are cannibalistic. Previous studies suggest that specialist phytoseiids practice kin recognition, while generalists use species recognition or discrimination due to the diet specification and frequent intraspecific interactions. We examined whether kin recognition is used by a type‐III generalist phytoseiid, Amblyseius herbicolus (Chant) (Acari: Phytoseiidae). The cannibalistic adults with different hunger levels (0‐, 24‐ and 48‐hr starvation) were given a choice of kin and a non‐kin larva. Kin recognition of A. herbicolus was affected by the hunger level. Adults not starved before the test significantly preferred cannibalizing non‐kin larva. Conversely, adults starved for 24 and 48 hr showed no statistically significant preference between kin and non‐kin larvae. Furthermore, the latency reflected hunger level, where not starved adults had the most prolonged latency, while adults starved for 24 and 48 hr had intermediate and shortest latency. This study suggests A. herbicolus use innate recognition mechanisms to avoid kin cannibalism since the adults and larvae had no prior association before the experiment. The effect of familiarization on kin recognition in A. herbicolus should be further investigated. [ABSTRACT FROM AUTHOR]

The importance of eristaline flies (Diptera, Syrphidae, Eristalini) as pollinators in natural ecosystems and for agricultural crops is well known. However, in‐depth studies on the life cycle of most of these species have yet to be carried out. The aim of this research was to study the life cycle of Eristalis tenax (Linnaeus, 1758) and Eristalinus aeneus (Scopoli, 1763) in order to improve the current rearing system employed at the University of Alicante. The results were analysed using the age‐stage, two‐sex life table method. As one of the main results, the mean duration of the life history of E. tenax and E. aeneus was 46.06 and 65.12 days (d), respectively. The most critical step for both species was found at the beginning of the larval stage (first instar), when the highest mortality was recorded. Population parameters were also analysed and compared. The intrinsic rate of increase (r), the finite rate of increase (λ), the net reproductive rate (R0) and the mean generation time (T) were 0.09 (d−1), 1.09 (d−1), 42.11 offspring and 40.97 d, in the case of E. aeneus and 0.05 (d−1), 1.05 (d−1), 23.13 offspring and 59.23 d, in the case of E. tenax. These results indicate that the current rearing system is more efficient for E. aeneus, which displays a faster population growth. However, some modifications need to be implemented to improve the production of E. tenax. [ABSTRACT FROM AUTHOR]

The use of predatory mites as the sole management tactic in biological control programmes frequently does not fully and reliably prevents damage of phytophagous mites on plants. Therefore, as an alternative, the integration of predatory mites with acaricides can provide more effective control of phytophagous mites than that of the predators only. However, for such integration, acaricides minimal negative impacts on predatory mites are required. In this study, we evaluated the sublethal effects of three acaricides on the foraging behaviour of Neoseiulus baraki (Athias-Henriot) (Acari: Phytoseiidae) in a coconut production system. The acaricides were assessed for interference with the location of prey habitat using a Y-tube olfactometer and for interference with the location of the prey colony within the habitat using a video-tracking system. In addition to the choice of odour source, the time required and the distance walked to make the choice were assessed. The acaricides tested were abamectin, azadirachtin and fenpyroximate. The predatory mite preferred coconuts infested with the coconut mite Aceria guerreronis Keifer (Acari: Eriophyidae) over uninfested coconuts when not exposed to acaricides. However, when exposed to acaricides, the predator did not distinguish between infested and uninfested fruits. When exposed to abamectin, N. baraki spent more time resting and walked greater distances before making the choice of an odour source. Thus, the acaricides impair the ability of the predatory mite N. baraki to locate a prey habitat and to locate a prey within that habitat. The acaricides differentially affected prey foraging by interfering with odour perception. [ABSTRACT FROM AUTHOR]

Artificial diets have been developed to sustain the mass rearing of a wide range of arthropod natural enemies, with varying success. In some cases, such diets can be optimized using insect-derived materials, such as haemolymph. In this study, we examined the effect of supplementing haemolymph of the black soldier fly, Hermetia illucens, to a basic artificial diet for the phytoseiid mite Amblyseius swirskii. The survival, development and reproduction of the predatory mite were assessed when fed on artificial diets composed of honey, sucrose, tryptone, yeast extract and egg yolk, supplemented with 5%, 10%, or 20% of H. illucens pre-pupal haemolymph. Developmental time from larva to adult was shorter for males and females offered artificial diets supplemented with 20% haemolymph vs. the basic diet. The oviposition rate and total fecundity of females reared on the basic diet were substantially lower than those of females supplied with the enriched diets. The intrinsic rate of increase was highest on the diet containing 20% haemolymph, followed by those containing 10% and 5% haemolymph. In a subsequent diet-switching experiment, mites fed on the basic diet in their juvenile stages were switched upon adulthood to diet enriched with different concentrations of H. illucens haemolymph. The females that were fed with the enriched diets from the adult stage on had higher oviposition rates and fecundities than those maintained on the basic diet, but their reproductive parameters were not significantly affected by the concentration of the haemolymph in the artificial diet. In conclusion, supplementing artificial diets with black soldier fly haemolymph significantly improved their nutritional value for A. swirskii. Our findings indicate the potential of using H. illucens as a cheap source for haemolymph in artificial diets, as the fly can be cost-effectively produced at a large scale on organic waste materials. [ABSTRACT FROM AUTHOR]

There is an increasing awareness that vegetation diversity can affect herbivore and natural enemy abundance and that plants can play a major role in directly manipulating natural enemy abundance for protection against herbivore attacks. Using data from cassava fields, we aimed at (i) testing the capacity of the predatory mite Typhlodromalus aripo to control the herbivorous mite Mononychellus tanajoa in a chemical exclusion trial; and (ii) testing, based on the differential preference by T. aripo for cassava cultivars, how combinations of two morphologically different cassava cultivars with differential suitability to the predator can improve its population densities on the non-favourable cultivar, thereby reducing M. tanajoa densities with subsequent increases in cassava yield. The study was conducted in a cassava field in Benin, West Africa. The experiments confirmed that T. aripo effectively suppresses M. tanajoa populations on both cultivars and showed, in the no-predator-exclusion experiments, that cultivar combinations have significant effects on M. tanajoa and T. aripo densities. Indeed, T. aripo load on the non-preferred cultivar was lowest in subplots where the proportion of T. aripo-preferred cultivar was also low, while, and as expected, M. tanajoa load on the non-preferred cultivar showed decreasing trends with increasing T. aripo densities. The possible mechanisms by which cultivar mixing could increase predator load on the non-favourable cultivar were discussed. Our data showed that appropriate cultivar combinations effectively compensate for morphologically related differences in natural enemy abundance on a normally predator-deficient cultivar, resulting in lower pest densities on the non-favourable cultivar. In practical terms, this strategy could, in part, enhance adoption of cultivars that do not support sufficient levels of natural enemies for pest control. [ABSTRACT FROM AUTHOR]

Humidification can suppress water loss from an organism and has great potential for improving the cold storage of short-lived arthropods, such as predatory mites. The effectiveness of humidity-controlled cold storage was recently verified for Neoseiulus californicus ( McGregor) females but was not examined for males. Combining both males and females in one storage protocol might increase the predator population because it would enhance the opportunity for multiple mating, which is necessary for females to maximize their egg production. Newly emerged adult males were stored at an air temperature of 5°C and relative humidity ( RH) of 100% or 80%. The median survival time ( LT50) was 32 days at 100% RH and 14 days at 80% RH; the survival curves differed significantly. Males stored at 100% RH for 0, 10, 20 and 30 days were introduced to virgin females for mating at 25°C to evaluate their reproductive ability. The pre-oviposition period was significantly prolonged in the females mated with males stored for ≥20 days. No negative effects of storage were observed on the oviposition period, total number of eggs or net reproduction rate ( R0) in the females mated with males stored for ≤20 days or on the mean generation time ( T) for those stored for 30 days. A slight decrease in the intrinsic rate of increase ( rm) was observed in the females mated with males stored for ≥20 days. Our storage method can preserve N. californicus males for 20 days with only a minor reduction in their survival and reproductive ability. [ABSTRACT FROM AUTHOR]

The herbivore-induced plant volatile (HIPV) methyl salicylate (MeSA) is widely present in the chemical profile of several plant species and is known to attract natural enemies, including predatory mites. In this study, the response of Typhlodromus pyri, a key predator of pest mites in west coast vineyards, to synthetically produced MeSA was tested using a Y-tube olfactometer in laboratory bioassays. Six doses ranging from 0.002 to 200 μg of MeSA diluted in 0.1 ml hexane were tested. Significantly higher proportions of T. pyri preferred MeSA at doses 0.02, 0.2 and 20 μg. No differences in response to MeSA were detected at the highest (200 μg), intermediate (2 μg) and lowest (0.002 μg) doses. Mite response to MeSA was a function of dose when fitting polynomial and logistic regression models using dose and square of the log dose prediction factors. Results indicate that synthetic MeSA may be applied to attract predatory arthropod populations in vineyards to enhance biological control of pest mites. [ABSTRACT FROM AUTHOR]

Neoseiulus californicus (McGregor) is a predatory mite employed for biological control of the agricultural pest Tetranychus urticae (Koch). We explored whether environmental differences, in this case the trichome densities of abaxial leaf surfaces of strawberry cultivars (‘Maehyang’ and ‘Sulhyang’ varieties) affect the functional response of adult female N. californicus preying on immature stages (egg, larva and nymph) of T. urticae. We also evaluated the functional response of N. californicus to eggs of T. urticae at different temperatures (15, 20, 25, 30 and 35°C). We conducted a logistic regression of the proportion of prey consumed as a function of initial prey density to identify functional response types, and used nonlinear least-squares regression and the random predator equation to estimate attack rates and handling times. The functional response of adult female N. californicus to T. urticae was not influenced by non-glandular trichomes on abaxial leaves but was affected by temperature. Overall, adult female N. californicus exhibited a type 2 functional response to T. urticae. The handling time of N. californicus was highest (1.9970 h) against T. urticae nymphs. The attack rate did not change much at 15–30°C, but was significantly higher at 35°C. The handling time decreased significantly with increasing temperature at 15–35°C. At 35°C, the attack rate was highest (0.2087) and the handling time was lowest (0.9511 h). [ABSTRACT FROM AUTHOR]

The developmental time and survival of immature stages of Neoseiulus californicus were studied at nine constant temperatures (12, 16, 24, 24, 28 32, 36, 38 and 40°C), 60–70% RH, and a photoperiod of 16 : 8 (L : D) h. The total mortality of immature N. californicus was lowest at 24°C (4.5%) and highest at 38°C (15.2%). The total developmental time decreased with increasing temperature between 12°C (18.38 days) and 32°C (2.98 days), and increased beyond 32°C. The relationship between the developmental rate and temperature was fitted by five nonlinear developmental rate models (Logan 6, Lactin 1, 2 and Briere 1, 2). The nonlinear shape of temperature development was best described by the Lactin 1 model (r2 = 0.98). The developmental variation of each stage was well described by the three-parameter Weibull distribution model (r2 = 0.91–0.93). The temperature-dependent developmental models of N. californicus developed in this study could be used to determine optimal temperature conditions for its mass rearing, to predict its seasonal population dynamics in fruit tree orchards or greenhouse crops, or to develop a population dynamics model of N. californicus. [ABSTRACT FROM AUTHOR]

The performance of herbivores, natural enemies and their interactions may be affected directly or indirectly by host plant traits, e.g. the physical plant characteristics may influence the search pattern and the functional response of predators. We studied the functional response of adult females of the predatory mite Neoseiulus cucumeris to first instar larvae of Thrips tabaci on three host plants (sweet pepper, eggplant and cucumber). The 24-h leaf disc experiments conducted at 25 ± 1°C, 60 ± 10% relative humidity and 16 : 8 h (light : dark) showed that N. cucumeris exhibited a type II functional response on all host plants. The following search rates and handling times were estimated from fitting the data to the disc equation 0.043/h and 1.798 h (cucumber); 0.048/h and 1.030 h (sweet pepper) and 0.0441/h and 2.294 h (eggplant) giving an estimated maximum predation of 13.35, 23.31 and 10.46 larvae per day respectively. The data from sweet pepper could also be described by the random predator equation ( a′: 0.051/h; Th: 0.472 h). The host plant species interacted significantly with prey density on the functional response of N. cucumeris with the relative differences in the number of thrips eaten on each host plant increasing with density. It is suggested that it is mainly the difference in trichome density between the three host plants that is responsible for the observed differences in the functional response of N. cucumeris. These results emphasize the importance of the host plant characteristics on the performance of natural enemies and for optimizing their use in biological control of pests. [ABSTRACT FROM AUTHOR]

Use of the predatory mite Neoseiulus cucumeris (Oudemans) (Acari, Phytoseiidae) and a fleece cover in combination with pyrethrum application showed potential for control of two important pests in organic production of strawberry ( Fragaria × ananassa Duch.), although there were some unexpected interactions between pyrethrum and the release of N. cucumeris that need to be investigated further. Two cultivars, Honeoye and Cavendish, were treated with pyrethrum with or without fleece to control strawberry blossom weevils [ Anthonomus rubi Herbst. (Col., Curculionidae)] and N. cucumeris was released to control strawberry mites [ Phytonemus pallidus (Banks) (Acari, Tarsonemidae)]. Number of strawberry mites, number of flower buds damaged by the weevil, incidence of grey mould and powdery mildew, and fruit yield were measured in two consecutive fruiting seasons. In Honeoye, the fleece in combination with pyrethrum decreased the proportion of damaged buds by 11–23% and increased yield by 49–91 g per plant. When pyrethrum was used alone it did not influence the number of damaged buds or yield. This indicates that the combined treatment was more effective because of the fleece. In Cavendish, the fleece and pyrethrum treatments were not found to be effective. Almost no P. pallidus was found in Honeoye and the results were not analysable. In plots with Cavendish where N. cucumeris had been released, there were approximately 50% fewer P. pallidus from the end of August onwards in 2003. However, this response did not significantly influence the succeeding year's yield. The number of fruits infected with fungi was very low and no effects were observed for any of the treatments. [ABSTRACT FROM AUTHOR]

The impacts of four pesticides used for control of citrus thrips, Scirtothrips citri (Moulton), were evaluated in both field and laboratory populations of a predaceous mite, Euseius tularensis Congdon. Abamectin and chlorfenapyr had the least impact of pesticides evaluated on a field population of E. tularensis and predaceous mite levels mirrored those observed in the untreated control but at a slightly depressed level. Spinosad reduced predaceous mites somewhat but they recovered to 50% of the level in the untreated control by the end of the trial. Mite populations were low throughout the trial in plots treated with cyfluthrin. As an overall summary statistic, cumulative predator mite-days ranged from 73.6% of the level observed in the untreated control with abamectin to 67.1% with chlorfenapyr, 36.8% with spinosad and 11.7% with cyfluthrin. Three additional field trials confirmed abamectin's minimal impact. In laboratory studies of adult female mite mortality on field-weathered, pesticide-treated leaves, cyfluthrin caused high mortality on day 1 after treatment and all mites that were not killed were driven off leaf discs until day 21. When mites were placed on leaf discs 1 day after treatment with abamectin, spinosad, or chlorfenapyr, 67.5% of the mites died on chlorfenapyr discs. By 7 days after treatment, no material but cyfluthrin showed a significant impact. Implications to citrus integrated pest management are discussed. [ABSTRACT FROM AUTHOR]

The acaricide hexythiazox (Acorit[sup ®] SC, 100 g a.i.l[sup –1]), the fungicide triadimefon (Bayleton spezial[sup ®] WG, 52 g a.i.kg[sup –1]) and the insecticide heptenophos (Hostaquick[sup ®] EC, 550 g a.i.l[sup –1]), were tested in the laboratory for their side-effects on the predatory mite Phytoseiulus persimilis A.H. The pesticides were either applied separately at a range of concentrations or in admixture to detached bean leaves using a Potter Tower to deposit 2 mg spray solution per cm[sup 2]. No significant differences in the mean mortality rate of the phytoseiid or in the mean reproduction per female was found between the different treatments. Total effect values ranged from 5.4 to 38.7% after separate application of the test products and from 8.9 to 25.5% after treatment with the various pesticide mixtures. [ABSTRACT FROM AUTHOR]

Studies on juvenile survival, development and reproduction of Euseius finlandicus Oudemans, Typhlodromus pyri Scheuten and Kampimodromus aberrans Oudemans feeding on crawlers of the diaspidid San José scale Quadraspidiotus perniciosus Comstock were conducted in the laboratory at 25 ± 1°C, 65 ± 5% RH and 16 h photoperiod. Immature life stages as well as adult females readily accepted crawlers as prey. All predatory species preying upon scale crawlers were able to complete development and to sustain reproduction during a 10-day-period. Immatures of E. finlandicus and K. aberrans had a low juvenile mortality, whereas nearly 50% of T. pyri protonymphs died. Mean development from larva to adult took 5.6 days in E. finlandicus, 13.2 days in K. aberrans and 17.4 days in T. pyri. E. finlandicus had a higher fecundity (0.7 eggs/day/female) than T. pyri (0.5 eggs/female/day) and K. aberrans (0.4 eggs/female/day). However, San José scale crawlers must be considered a suboptimal prey. Its nutritional value is discussed in relation to that of more adequate food sources. Data on development and fecundity are also discussed in relation to other phytoseiid species feeding on armoured scale insects. [ABSTRACT FROM AUTHOR]

The effects of different relative humidities (50%, 55%, 65%, 75%, 85% and 100% RH) on egg hatch were tested at 25 ± 1°C for three strains of Euseius finlandicus Oudemans, two strains of Typhlodromus pyri Scheuten and two strains of Kampimodromus aberrans Oudemans. At decreasing humidity, egg mortality increased earlier in K. aberrans than in E. finlandicus and T. pyri. E. finlandicus and T. pyri had similar humidity responses. Differences between strains within each species were small. RH50 values (relative humidity at which 50% of eggs hatch) were 50.4%, 52.4% and 53.1% for strains of E. finlandicus, 51.8% and 53.3% for strains of T. pyri, and 55.3% and 57.5% for strains of K. aberrans, respectively. Eggs of the Finnish E. finlandicus strain were most drought resistant (50.4% RH50), eggs of the French K. aberrans strain were most sensitive (57.5% RH50). The results are discussed in relation to the abundance of these species on certain plants and to the humidity responses of other phytoseiids. [ABSTRACT FROM AUTHOR]

Abstract: The model introduced here is an open test which produces experimental results of the same quality as a former test model and at the same time achieves considerable savings in both time and materials. The characteristic feature of the present method is that the mites are kept on a treated glass surface floating on water. The water forms a natural barrier ensuring that the mites cannot escape from the treated area. [ABSTRACT FROM AUTHOR]