Predatory Mite Research Articles

Plant, pest and predator interplay: tomato trichomes effects on Tetranychus urticae (Koch) and the predatory mite Typhlodromus (Anthoseius) recki Wainstein.

Trichomes are well-known efficient plant defense mechanisms to limit arthropod herbivory, especially in Solanaceae. The present study aims to evaluate the impact of trichome types on the development, survival and dispersal of Tetranychus urticae, and the phytoseiid predatory mite Typhlodromus (Anthoseius) recki. Six Solanum lycopersicum cultivars and two wild Solanum species, S. cheesmaniae and S. peruvianum, presenting contrasting densities and types of trichomes, were considered. Cultivars and species were characterized by counting each trichome type on leaves, petioles and stems. Mites stuck on petiole and stem and alive mites on the leaflet used for mite release and in the whole plant were counted three weeks after T. urticae plant infestation. Tetranychus urticae settlement and dispersal were differently affected by trichomes. Trichome types V and VI did not affect settlement and dispersal, whereas trichome types I and IV on the petiole had the highest impacton mites. Trichomes on leaves slightly affected mite establishment, there appears to be a repellent effect of trichome types I and IV. The low densities of both T. urticae and its predator detected for the cv. Lancaster could not be clearly associated to the trichome types here considered. The predator did not seem to be affected by plant characteristics, but rather by T. urticae numbers on the plant. The trichome traits unfavorable to T. urticae, did not affect the predator which showed high efficiency to control this pest on all the plant genotypes considered, but at a favorable predator:prey ratio (1:1). Altogether, these results are encouraging for the use of T. (A.) recki as a biological control agent of T. urticae regardless of the trichome structure of the tomato cultivars, but other conditions should be tested to conclude on practical implementations.

Acute toxicity effects of pesticides on predatory snout mites (Trombidiformes: Bdellidae).

Predatory mites biologically control a range of arthropod crop pests and are often central to agricultural IPM strategies globally. Conflict between chemical and biological pest control has prompted increasing interest in selective pesticides with fewer off-target impacts on beneficial invertebrates, including predatory mites. However, the range of predatory mite species included in standardized pesticide toxicity assessments does not match the diversity of naturally occurring species contributing to biocontrol, with most testing carried out on species from the family Phytoseiidae (Mesostigmata). Here, we aim to bridge this knowledge gap by investigating the impacts of 22 agricultural pesticides on the predatory snout mite, Odontoscirus lapidaria (Kramer) (Trombidiformes: Bdellidae). Using internationally standardized testing methodologies, we identified several active ingredients with minimal impact on O. lapidaria mortality, including Bacillus thuringiensis,nuclear polyhedrosis virus, flonicamid, afidopyropen, chlorantraniliprole, and cyantraniliprole, which may therefore be good candidates for IPM strategies utilizing both chemical and biological control. Comparison of our findings with previous studies on Phytoseiid mites reveals important differences in responses to a number of chemicals between predatory mite families, including the miticides diafenthiuron and abamectin, highlighting the risk of making family-level generalizations from acute toxicity assessments. We also tested the impacts of several pesticides on a second Bdellidae species (Trombidiformes: Bdellidae)and found differences in the response to chlorpyrifos compared with O. lapidaria, further highlighting the taxon-specific nature of nontarget toxicity effects.

Life table parameters of Amblyseius largoensis, Amblyseius swirskii and Proprioseiopsis lenis (Acari: Phytoseiidae) fed on eggs and larvae of Frankliniella occidentalis.

The immature development and reproduction of the predatory mites Amblyseius largoensis (Muma), Proprioseiopsis lenis (Corpuz and Rimando), and Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) were investigated using both thrips eggs and first instars of the western flower thrips, Frankliniella occidentalis Pergande, as prey in a controlled laboratory environment at 25°C and 60% relative humidity. When provided with thrips eggs as food, A. largoensis exhibited a notably shorter immature development period for both males (7.05 days) and females (6.51 days) as compared with A. swirskii (8.05 and 7.19 days, respectively) and P. lenis (8.10 days and 7.05 days, respectively). Amblyseius largoensis also displayed a higher oviposition rate (2.19 eggs/female/day) than A. swirskii and P. lenis (1.79 and 1.78 eggs/female/day, respectively). Moreover, it exhibited the highest fecundity (25.34 eggs/female), followed by P. lenis (24.23 eggs/female) and A. swirskii (22.86 eggs/female). These variations led to A. largoensis having the highest intrinsic rate of increase (rm) at 0.209, followed by A. swirskii at 0.188, and P. lenis at 0.165. However, when the predatory mites were provided with first instars of F. occidentalis, A. swirskii demonstrated a faster immature development period for both males (7.67 days) and females (7.59 days) as compared with P. lenis (9.00 days and 7.86 days, respectively) and A. largoensis (8.47 days and 8.61 days, respectively). While the oviposition rates of P. lenis (1.92 eggs/female/day) and A. swirskii (1.90 eggs/female/day) were similar when feeding on this prey, A. largoensis produced fewer eggs (1.83 eggs/female/day). Further, A. swirskii exhibited the highest fecundity (31.93 eggs/female), followed by A. largoensis (25.71 eggs/female) and P. lenis (23 eggs/female). Consequently, the intrinsic rate of increase (rm) on thrips first instars was highest in A. swirskii (0.190), followed by A. largoensis (0.186), and P. lenis (0.176). In summary, our findings indicate that in terms of life history parameters A. largoensis performs optimally when feeding on thrips eggs, whereas A. swirskii performs best when preying on the mobile first instars of the thrips. These insights into the dietary preferences and reproductive capabilities of the studied predatory mite species have important implications for their potential use as biological control agents against F. occidentalis in agricultural settings.

Effects of Prey Switching at Different Stages on Life Parameters of Neoseiulus bicaudus

The phenomenon of prey switching is prevalent in the natural world and represents a strategic adaptation of predators to their environment. Neoseiulus bicaudus, a native predatory mite found in Xinjiang, serves as a natural enemy to numerous small pests. The utilization of Tyrophagus putrescentiae as an alternative prey for the mass breeding of N. bicaudus is employed to fulfill the demands of enhanced breeding efficiency and cost-effectiveness. Following the introduction of mass breed N. bicaudus into the agricultural ecosystem, there was a switching in the prey of N. bicaudus from Ty. putrescentiae to Tetranychus turkestani. The objective of this study was to investigate the impact of prey switching at various stages on N. bicaudus. This study employed the age-stage, two-sex life table to assess the life parameters of N. bicaudus undergoing prey switching at different stages. The results showed that the survival rate of N. bicaudus was significantly decreased, the developmental period was significantly prolonged, the fecundity was improved during prey switching, and the intrinsic rate of increase of N. bicaudus was significantly decreased. The negative effects of prey switching in larva and deutonymph stages were greater than those in protonymph and adult stages. The stage and age of N. bicaudus undergoing prey switching were positively correlated with the male ratio, and negatively correlated with the total preoviposition period and the mean generation time. The comprehension of prey switching effects on N. bicaudus can enhance our understanding of the predator adaptation to environmental changes and contribute to the artificial rearing and application of natural enemy.

Effect of Methyl Jasmonate on the Performance of Tetranychus evansi Baker & Pritchard, 1960 (Acari: Tetranychidae) and Phytoseiulus longipes Evans, 1968 (Acari: Phytoseiidae) on Tomato Plants

Inducible anti-herbivore defenses in plants are predominantly regulated by jasmonic acid (JA). The red spider mite Tetranychus evansi Baker & Pritchard, 1960 (Acari: Tetranychidae) is an invasive pest known for its detrimental impact on tomato plants and other Solanaceae crops. Here, we investigated the extent to which T. evansi and the predatory mite Phytoseiulus longipes Evans, 1968 (Acari: Phytoseiidae) are affected by induced JA-defenses. Initially, we artificially induced the JA-response in tomato plants using exogenous methyl jasmonate (MeJA) and subsequently assessed the effect of JA defenses on spider mite by evaluating mortality and oviposition rates. Our findings revealed a higher mortality and lower oviposition rates on plants treated with MeJA compared to non-treated control plants. Furthermore, we examined the predatory mite's predation rates on spider mite eggs produced on MeJA-treated and non-treated tomato plants. The results showed a reduced predation on T. evansi eggs derived from MeJA-treated plants, indicating a potential negative impact of JA-induced defenses on the predator's performance. Finally, we released five predatory females on T. evansi-infested tomato plants treated and non-treated with MeJA, monitoring the predator population density for three generations. Predator population was not affected, as the abundance of larvae and adults was not significantly different between treatments. These findings underscore the negative impact of JA defenses on herbivores and highlight the trade-off it may pose on natural enemies.

Adult females and larvae of the predatory mite Gynaeseius liturivorus avoid cannibalism via kin recognition

Adult females and larvae of the predatory mite Gynaeseius liturivorus avoid cannibalism via kin recognition

Are predatory mites effective as biological control agents to suppress Oligonychus ilicis (Acari: Tetranychidae) in blueberry plantings?

Southern red mite, Oligonychus ilicis McGregor (Acari: Tetranychidae), is an important polyphagous spider mite pest that causes economic damage to many ornamentals, coffee, and fruit crops. Blueberry growers in the Southeastern United States, including Florida and Georgia, have experienced severe losses due to outbreaks of O. ilicis. Predatory mites are an important management tool used for controlling spider mites; however, predators have not been studied and successfully evaluated in blueberry systems. Amblyseius swirskii Athias-Henriot, Phytoseiulus persimilis Athias-Henriot, and Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) are among the most economically important arthropod agents used in augmentative biological control worldwide. To evaluate the potential of these 3 commercially available predatory mites for use in blueberry plantings, we conducted experiments under controlled laboratory conditions and in the greenhouse. In preliminary laboratory experiments, P. persimilis and N. californicus significantly reduced the number of O. ilicis motile stages below those found in the untreated control, indicating the potential for these 2 predatory mite species to suppress O. ilicis populations. Amblyseius swirskii did not perform well controlling O. ilicis motiles in the laboratory. Under greenhouse conditions, N. californicus and P. persimilis significantly reduced the number of eggs after 7 days of release and the number of motile stages after 14 days of release. This is the first report of using phytoseiid mites to suppress O. ilicis in blueberry systems in the United States. Further studies on predator behavior, feeding preferences, and acaricide compatibility with predators are required to investigate the possibility of using P. persimilis, and N. californicus as biological control agents of O. ilicis in blueberry systems.

Phytoseiidae (Acari: Mesostigmata) of the subfamily Amblyseiinae from Brazil

Phytoseiidae is composed of essentially predatory mites most commonly found on the aerial plant parts. Presently, it is considered to contain about 2,650 valid species, divided into nearly 102 genera of three subfamilies: Amblyseiinae, Phytoseiinae and Typhlodrominae. Approximately 250 of those have been reported from Brazil. Amblyseiinae is the largest subfamily, with about 65% of the described species. This publication summarises the morphologic, taxonomic and distributional information of the Amblyseiinae reported from Brazil, in support of future research on their conservation and practical use. A total of 195 valid species of 29 genera of Amblyseiinae is listed in this publication, 121 of which were described from this country, including seven species which are most certainly incorrect reports, based on the present state of knowledge. Two new combinations are proposed: one in Amblyseius, Amblyseius malvus (Denmark & Evans), and one in Transeius, Transeius piracicabae (Denmark & Muma). Six new synonyms are proposed (Chelaseius lativentris Karg, T. piracicabae, Euseius errabundus De Leon, Typhloromalus clavicus Denmark & Muma, Typhlodromips fordycei (De Leon) and Typhlodromips mangleae De Leon, as senior synonyms of Chelaseius brazilensis Denmark & Kolodochka, Transeius gervasioi Rocha, Silva & Ferla, Euseius plaudus Denmark & Muma, Typhlodromalus simus Denmark & Muma, Typhlodromips igapo Nuvoloni, Lofego, Rezende & Feres and Typhlodromips pederosus El-Banhawy, respectively). A key is provided to help in the separation of the species reported. So far, the most diverse genera in Brazil (followed by the number of species reported) are: Amblyseius Berlese (48), Neoseiulus Hughes (23), Typhlodromips De Leon (22), Iphiseiodes De Leon (14), Amblydromalus Chant & McMurtry (13) and Euseius Wainstein (12). The highest number of species is reported from the southeastern region (119 species), followed by the northeastern (82), the northern (68), the southern (65) and the midwestern (52). The states with highest numbers of registered species are São Paulo (109), Bahia (70), Rio Grande do Sul (62), Amazonas (47), Pernambuco (44) and Minas Gerais (43), while those with lowest numbers are Rio Grande do Norte (16), Sergipe (12), Pará (12), Rondônia (7) and Amapá (5). At least in part, those differences might be related to the dedicated searching effort.

Within-tree distribution and seasonal dynamics of Eutetranychus banksi and Euseius stipulatus (Acari: Tetranychidae, Phytoseiidae) on citrus: Implications for the biological control of the pest

The Texas citrus mite, Eutetranychus banksi (McGregor) (Acari: Tetranychidae), is a citrus pest widely distributed throughout the Americas and recently introduced in Spain. In this study we studied the within-tree distribution of E. banksi and the predatory phytoseiid mites, identify the phytoseiid species associated with the pest, and describe the seasonal trends to analyse the predator’s behaviour in response to the increase in pest density, allowing evaluation of biological control possibilities. The Texas citrus mite was mainly found on the adaxial (upper) side of leaves from the current year's shoots located at the periphery of the tree canopy, whereas phytoseiids prefer the abaxial (lower) side of leaves inside the tree canopy. The spider mite preferred to feed on leaves rather than fruits, whereas phytoseiids use both substrates equally. Eutetranychus banksi showed a single population peak in late summer-early autumn, while phytoseiids showed two peaks, a main spring peak and a second less abundant in autumn. The seasonal dynamics of E. banksi and phytoseiids on fruits occurred in parallel to those recorded on leaves. Euseius stipulatus (Athias-Henriot) was the most frequent and abundant phytoseiid species, apparently displacing other predatory mites. In autumn, when E. banksi reached high densities, phytoseiids moved from the leaf abaxial sides inside the tree canopy to the adaxial sides on the periphery and to the fruits, to feed on E. banksi. In addition, a change in phytoseiid colouration from white to reddish-brown was observed. Both, the number of red phytoseiids and their leaf occupation increased significantly in response to the prey population growth, which was indirect evidence of their contribution to the biological pest control. However, the low predator:prey ratios observed cannot avoid the pest population growth.

Diversity of phytophagous and predatory mites in vegetable crops in Himachal Pradesh, India

The surveys carried out in different vegetable growing areas of Himachal Pradesh yielded 25 species of mites belonging to 9 genera under 5 families. Among all, 5 species were phytophagous, 19 were predatory mites and 1 species was of saprophagous mite. On capsicum, a predatory mite of the family Anystidae was recorded for the first time from the state. During the study, majority of predatory mites were recorded on cucumber and brinjal than other vegetables. Four species are the new reports from Himachal Pradesh.

Leaf trichome-mediated predator effects on the distribution of herbivorous mites within a kidney bean plant.

Some predators prefer to settle on leaf patches with microstructures (e.g., trichomes and domatia), leaving traces on the patches. Herbivorous arthropods, in turn, select leaf patches in response to these traces left by predators. It remains unclear whether traces of predators on leaf patches affect the distribution of herbivorous prey within plants through plant microstructure. Therefore, we examined the distribution of herbivorous mite (Tetranychus urticae) and predatory mite (Phytoseiulus persimilis) by investigating their oviposition pattern. We used a kidney bean plant (Phaseolus vulgaris) with two expanded primary leaves and the first trifoliate leaf, focusing on leaf trichomes as the microstructure. The density of trichomes was higher on the first trifoliate leaf than on the primary leaves and on the abaxial surface of the leaves than on the adaxial surface. Adult female P. persimilis laid more eggs on the first trifoliate leaf to the primary leaves. Although adult female T. urticae preferred to oviposit on the abaxial surface of primary leaves, previous exposure of plants to predators diminished this preference. The altered egg distribution would be a response to the traces of P. persimilis rather than eggs of P. persimilis. Our findings indicate that T. urticae reproduces on leaf patches with traces of predators without altering their oviposition preference. Given that the presence of predator traces is known to reduce the reproduction of T. urticae, it may have a substantial effect on the population of T. urticae in the next generations on kidney bean plants.

Combined application of entomopathogenic fungi and predatory mites for biological control of Tetranychus urticae on chrysanthemum.

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

Development of Menthyl Esters of Valine for Pest Control in Tomato and Lettuce Crops.

Menthyl ester of valine (MV) has been developed as a plant defense potentiator to induce pest resistance in crops. In this study, we attempted to establish MV hydrochloride (MV-HCl) in lettuce and tomato crops. When MV-HCl solutions were used to treat soil or leaves of potted tomato and lettuce plants, 1 µM MV-HCl solution applied to potted plant soil was most effective in increasing the transcript level of defense genes such as pathogenesis-related 1 (PR1). As a result, leaf damage caused by Spodoptera litura and oviposition by Tetranychus urticae were significantly reduced. In addition, MV-HCl-treated plants showed an increased ability to attract Phytoseiulus persimilis, a predatory mite of T. urticae, when they were attacked by T. urticae. Overall, our findings showed that MV-HCl is likely to be effective in promoting not only direct defense by activating defense genes, but also indirect defense mediated by herbivore-induced plant volatiles. Moreover, based on the results of the sustainability of PR1 expression in tomato plants treated with MV-HCl every 3 days, field trials were conducted and showed a 70% reduction in natural leaf damage. Our results suggest a practical approach to promoting organic tomato and lettuce production using this new plant defense potentiator.

Predation of Raoiella indica (Acari: Tenuipalpidae) by Stethorus tridens Gordon (Coleoptera: Coccinellidae)

The red palm mite (RPM), Raoiella indica Hirst (Acari: Tenuipalpidae), is an invasive species in several American countries and has a wide range of hosts, causing significant damage, mainly to coconut and banana crops. Previous studies conducted in America have focused on the biological control of RPM through predatory mites and insects. Stethorus tridens Gordon (Coleoptera: Coccinellidae) is considered a promising biocontrol agent of phytophagous mites it has been observed on several cultures, and has a high predatory capacity. The aim of this study was to investigate S. tridens preferences among different developmental stages of RPM and estimating the functional and numerical responses of S. tridens over its most preferred prey-stage. Furthermore, the prey preference of S. tridents was examined between eggs of Tetranychus evansi Baker and Pritchard (its natural prey) and eggs of RPM through two-choice and non-choice experiments. The results showed that S. tridens prey on all developmental stages of RPM, with a marked preference for eggs over other stages of RPM. The functional response of this predator was type III, as consumption increased rapidly at intermediate egg densities. Predation on RPM eggs was unable to stimulate S. tridens reproduction, even at the highest densities. When we compared the food preference of S. tridens to eggs of T. evansi and RPM, we found that the predator preferred tetranychids. The results of this study suggested that RPM can be used as alternative prey to S. tridents, serving as a source of energy and allows for maintenance but not its reproduction.

How do different agricultural managements interfere with the Phytoseiidae mite (Acari: Phytoseiidae) community in apple trees?

In this study we performed the sampling of phytoseiid mites in different apple production orchards, and we evaluated the richness and abundance of these mites, as well as their distribution in the different strata of the plants. Furthermore, we studied how the different apple tree cultivars affect the diversity and distribution of these predatory mites. Collections were carried out in apple orchards in three different production areas: 1- organic agriculture (Antônio Prado, RS); 2- conventional agriculture (Muitos Capões, RS); 3- regenerative agriculture (São Joaquim, SC). In total, seven orchards were evaluated, in Muitos Capões and São Joaquim, two orchards of the Fuji and Gala, whereas in Antônio Prado, three cultivars (Eva, Fuji and Gala) were considered. In each orchard, 40 plants were evaluated, and from each plant a median branch was randomly chosen from which a leaf was removed from the apical, median and basal thirds. The collected leaves were taken to the laboratory, they were observed and the mites found mounted in Hoyer's medium and identified. A total of 695 phytoseiid specimens were collected. Greater abundance was noted in the apical stratum of plants of the Gala cultivar, demonstrating the effect of cultivar and stratum on phytoseiid richness, abundance and distribution. Neoseiulus californicus (McGregor) (Phytoseiidae) was the main species in areas of conventional and regenerative cultivation, being present in all evaluated orchards, but with low occurrence in areas of organic management. In organic orchards, species of the genus Euseius [Euseius mesembrinus (Dean) and Euseius inouei (Ehara and Moraes)] (Phytoseiidae) were more abundant. The results suggest that producers consider less intensive use of pesticides and herbicides in orchards in order to maintain populations of predatory mites due to their potential for biological control.

Maternal Care Behavior and Its Consequences in Competition.

Parental care behavior has evolved as a life history strategy to improve reproductive success, particularly in organisms facing challenging environments. However, the variation in maternal care, such as egg-guarding behavior in response to the social environment and the associated ecological consequence of competition, remains largely unknown. This study addresses a gap in current knowledge by examining the plasticity of maternal care behavior in the predatory mite C. eruditus and its impact on offspring survival and intra- and interspecific competition. Our results demonstrated that the reproductive females frequently exhibit egg-guarding behaviors, with enhanced maternal care efforts when the interspecific competitor is present. Egg masses are significantly more vulnerable to predation in the absence of maternal care. Guarding females increased egg survival rates and adversely influenced the survival of both con- and heterospecific competitors, with higher mortality rates being detected. Our findings highlight the ecological significance of maternal care behaviors and suggest that releasing C. eruditus and Neoseiulus cucumeris (Oudemans) together is not recommended for pest management in storage products.

Ecologo-faunistic review of tetranychid (Acariformes: Tetranychoidea) and phytoseiid mites (Parasitiformes: Phytoseiidae) in the Transcarpathian Region, Ukraine</p >

The results of long-term research on tetranychid and phytoseiid mites in the Transcarpathian region of Ukraine are summarized. Transcarpathian Tetranychoidea are represented by 28 species from 10 genera, and the same list for Phytoseiidae included 49 species from 11 genera. For 77 species of mites from 21 genera, species composition, abundance, trophic specialization, and biotopic distribution in different altitudinal zones of Transcarpathia, Ukraine was analysed. Ten species of tetranychid mites (Bryobia rubrioculus, Tetranyhus horridus, Amphytetranyhus viennensis, Eotetranycuus carpini, E. quercicola, Neotetranychus rubi, Oligonychus ununguis, Panonychus ulmi, T. turkestani and T. urticae), and 11 species of phytoseiid mites (Neoseiulus umbraticus, Kampimodromus aberrans, Amblyseius andersoni, A. rademacheri, Euseius ucrainicus, Dubininellus echinus, D. juvenis, Typhloctonus aceri, T. tuberculatus, Anthoseius (A.) rhenana and A. (A.) clavata) were common to all three studied altitudinal zones. The species diversity of tetranychids was highest in the lowlands (23 species), slightly lower in the foothills (19 species), and the lowest in the mountain zone (11 species). For phytoseiid mites, it was the highest in the foothills (38 species), 25 in the lowlands and 21 in mountains. Among the tetranychids, the transzonal species A. viennensis retained its dominant status in all altitudinal zones. In the lowland, the highest rates of occurrence and dominance indices were observed for the species B. rubrioculus and T. turkestani, and in the foothills—for P. ulmi and T. horridus. The species composition of mites in the lowlands and mountains varied the most for both predators and phytophagous mites. Among the tetranychids, the most striking marker species in the mountains were P. ulmi and N. rubi. Only in the mountains were found such phytoseiid species as N. alidis, N. montanus, T. runiacus, T. mutatus, and A. salviae, which could thus be considered strictly mountainous. All of them have fragmented habitats and are tied to mountainous regions. In that altitudinal zone, an exceptionally high occurrence rate and dominance index were established for N. montanus among the phytoseiids. This is most probably due to significantly greater differences in the temperature and humidity regimes and range of host plants and, for predatory mites, prey species. The results of this study provide additional information about the structure of the communities of phytophagous and predatory mites in the natural zones of the mountain landscape and changes in the composition of the communities under the influence of environmental factors and the forage base, which is a consequence of the altitudinal distribution of the investigated biocenoses.

The influence of photoperiod on development and population growth performance of the Phytoseiulus persimilis fed on Tetranychus urticae

ABSTRACT Environmental factors, such as photoperiod, can play an important role in the development of mites. The influence of photoperiod (L:D = 4:20, 8:16, 12:12, 16:8 and 20:4) on the development and population parameters of the predatory mite, Phytoseiulus persimilis Athias-Henriot fed on two-spotted spider mite, Tetranychus urticae Koch was examined under laboratory conditions. Pre-adult development decreased with increasing photoperiod until 12 h, after which the development period progressively increased. Longevity of both sexes demonstrated significant differences throughout photoperiods, with the longest at 20:4 L:D and the shortest at 8:16 L:D. The highest value of mean total fecundity was 13.62 egg/female at 12:12 L:D photoperiod. The net reproductive rate (R 0), the intrinsic rate of increase (r) and the finite rate of increase (λ), showed the highest value at 12:12 L:D. The R 0, r and λ for P. persimilis increased with increasing photoperiod from 4:20 to 12:12 L:D, but decreased sharply at the 16:8 and 20:4 L:D treatments. Our findings indicate that photoperiod has a significant role in advancing the rate of development, survival rate, and reproduction for commercial production of P. persimilis, with a 12:12 photoperiod length recognized as the ideal period for commercial production in culture.

An Integrated Pest Management Strategy Approach for the Management of the Stable Fly Stomoxys calcitrans (Diptera: Muscidae).

Stable flies, Stomoxys calcitrans, stand as formidable pests with a global impact, inflicting significant economic losses on the livestock sector. Larval development occurs in diverse substrates, including decomposing plant material and manure, while emerged adults pose a threat through blood-feeding on both animals and humans. Conventional chemical control methods, predominantly reliant on insecticides, not only pose environmental risks but also face challenges of resistance among stable fly populations. To address this pressing issue, we propose an integrated pest management (IPM) strategy for stable fly control. This approach involved a combination of sanitary-cultural practices, animal protection, the release of natural enemies targeting immature stages, and a specialized trapping system for adults. The Stomoxycc® trap, designed for mass trapping of adult Stomoxys, was employed alongside the release of the predatory mite Macrocheles robustulus and two wasp parasitoids, Spalangia cameroni and Muscidifurax raptor (under the commercial brands Biomite® and Biowasp®) on animal bedding as a key component of this IPM strategy. The implementation of this initiative has been undertaken at a significant sanctuary for donkeys and mules in western Spain. In this publication, we present the application and results of the IPM strategy utilized and provide insights into its use as a sustainable and environmentally friendly option for controlling stable fly populations.

Biological Control of Three Major Cucumber and Pepper Pests: Whiteflies, Thrips, and Spider Mites, in High Plastic Tunnels Using Two Local Phytoseiid Mites.

To enhance food security, food safety, and environmental health, a bio-based integrated pest management (BIPM) strategy was evaluated at two coastal locations in Lebanon as an alternative to toxic pesticide sprays in commercial high-arched plastic tunnels common in many countries. The evaluation occurred during two cucumber and pepper cropping seasons: spring and fall. At each site, two commercial tunnels were used; farmers' conventional practices were applied in one tunnel, while the BIPM approach was followed in the second tunnel. In the farmers' practices, a total of 14 sprays of insecticide/acaricide mixtures were applied during the spring growing season, and 6 sprays were applied during the fall. In the BIPM tunnels, hotspot releases of local strains of Amblyseius swirskii and Phytoseiulus persimilis were applied. By the end of the spring season, the number of whitefly nymphs (WFNs)/leaf and thrips/leaf in the pesticide treatment were 4.8 and 0.06, respectively, compared to 0.1 and 0.33, respectively, in the BIPM treatment. Similarly, at the end of the fall season, the WFNs reached 19.7/leaf in the pesticide control as compared to 1.2/leaf in the BIPM treatment, proving the efficacy of A. swirskii. Farmers using conventional acaricides during both cropping seasons failed to control Tetranychus urticae, the two-spotted spider mite (TSSM). However, hotspot releases of P. persimilis were successful in controlling TSSM. By the end of June, the number of TSSMs reached 7.8/leaf in the BIPM treatment compared to 53/leaf in the pesticide treatment. Likewise, in December, TSSM numbers reached 9/leaf in the BIPM treatment compared to 40/leaf in the pesticide treatment. Preliminary observations of pepper showed that both predatory mites (A. swirskii and P. persimilis) gave similar or better efficacy against the three pests. The two local predatory phytoseiid mites seem to be effective in controlling these three major pests and to be adapted to local environmental conditions. A rate of increase of 0.86 was observed for P. persimilis and 0.22 for A. swirskii, in June, when maximum temperatures were close to 40 °C. This also shows a compatibility between the two predators. In conclusion, our BIPM approach was efficient under a Mediterranean climate in arched plastic tunnels with relatively poor aeration.