Predatory Mite Species Research Articles

Functional responses of predatory mites, Cheyletus eruditus (Schrank) and Cheyletus malaccensis Oudemans (Trombidiformes: Cheyletidae) to Liposcelis decolor (Pearman) (Psocodea: Liposcelididae)

Psocids (Psocodea: Liposcelididae) are stored-product pests that are not easily managed by standard management tools and practices, such as insecticides. Biological control can be an effective alternative or complement to pesticides in the management of psocids in some scenarios. This study was carried out to evaluate the efficiency of two predatory mite species, Cheyletus eruditus (Schrank) and Cheyletus malaccensis Oudemans (Trombidiformes: Cheyletidae) to manage Liposcelis decolor (Pearman) (Psocodea: Liposcelididae), a key stored product psocid pest species that is phosphine tolerant. The functional responses of these two cheyletid mites to nymphs, adult males and females of L. decolor was determined under laboratory conditions at 24 ± 1 °C and 0: 24 (L: D) photoperiod. Based on the results of maximum likelihood estimates (MLE) of a logistic regression analysis, the functional responses of both the predatory mites to nymphs and adult males or females of L. decolor were Holling Type II. Subsequent estimations of attack rate (a), handling time (Th), maximum predation (K), and predation efficiency (η) per day (d) using a linearly transformed Hollings Type II model for predators against prey life stages revealed that C. eruditus performance was preferable compared to that of C. malaccensis. Similarly, the per capita consumption rate and searching efficiency of C. eruditus were considerably higher compared to C. malaccensis for all life stages of L. decolor. Nevertheless, further studies are required to validate the efficiency of C. eruditus and C. malaccensis based on other evaluation criteria including field trials, and their compatibility with other management strategies targeted at stored product pests in order to facilitate the incorporation of these mite species into existing IPM systems for managing psocids.

Mites associated with Vitis labrusca (Vitaceae) in southern Brazil: Population dynamics and ecology

Viticulture is one of the main economic activities in Rio Grande do Sul (RS), Brazil, with emphasis on the American grape varieties, Vitis labrusca L. (Vitaceae), used in producing juices and wines. The present work aimed to identify the mite species associated with American grapevines (V. labrusca), their possible natural enemies, and their population fluctuations. The selected varieties were: Bordô (Bd) and Couderc (Cc and Cd) in Dois Lajeados (RS), Bordô (Bi) in Imigrante (RS) and Bordô (Bp), in Putinga (RS). The study was conducted monthly between March 2017 and March 2018, evaluating 20 randomly selected plants from each municipality. We found 5,452 mites belonging to 13 families, distributed across 29 genera and 42 species, or belonging to the suborder Oribatida. Higher mite richness was observed on Cc (12 species) and higher abundance on Cd (2,812 specimens), Cc (868) and Bi (799). Among the predatory mite families, Stigmaeidae had the highest abundance (896 specimens), followed by Phytoseiidae (746). The most abundant species observed were Euseius mesembrinus (Dean), Agistemus riograndensis Johann & Ferla, Tydeus californicus (Banks), Polyphagotars-onemus latus (Banks) and Tarsonemus sp. This is the first study in southern Brazil that evaluates and reports the mite fauna and its ecology on American grape varieties, with high abundance and frequency of predatory mites. This work is important to assist in implementing management techniques that promote the maintenance of predatory mite species in these vineyards.

Neoseiulus pseudomarginatus sp. nov., a new species of predatory mites (Acari: Phytoseiidae) continuously misidentified as Neoseiulus marginatus (Wainstein) from the Mediterranean countries

Many previous descriptions of Phytoseiidae (Acari: Mesostigmata) species lack some important morphological characteristics including the number of dorsal solenotomes (gland pores). However, the importance of the presence or absence of a single pair of solenostomes to identify two distinct species in some phytoseiid genera, such as Kampimodromus Nesbitt and Neoseiulus Hughes has previously been confirmed by molecular studies in several cases. Neoseiulus marginatus (Wainstein) was originally described from Kazakhstan, a country located in Central Asia, based on the specimens collected from herbaceous plants. It was subsequently reported and redescribed from a series of Western Palearctic countries. However, the material first redescribed from Crimea and thereafter from Armenia, Greece, Israel, and Turkey, by having gd5 solenostomes, is distinct from the original N. marginatus described by Wainstein. Indeed, our examinations of its type specimens confirmed that gd5 pores are consistently absent in the type series of N. marginatus. Therefore, this species is redescribed and illustrated based on the female lectotype. In addition, N. pseudomarginatus sp. nov., a widely distributed species in the Western Palearctic countries, which has seven pairs of solenostomes is described as a new taxon for science. Furthermore, our examinations of the type specimens of N. polyporus (Wainstein) indicated that it should be considered as a junior synonym of N. marginatus, as already suggested in earlier studies.

A tiny cuckoo: Risk‐dependent interspecific brood parasitism in a predatory mite

Abstract Many animal species protect their eggs against predators, and other species may profit from this by adding their eggs to those of the protecting species. We studied two tiny species of predatory mites that share a food source, are engaged in intraguild predation, and which eggs are attacked by the same egg predator. One of these predatory mites (Neoseiulus californicus) adds its eggs to those of the other species (Gynaeseius liturivorus) which guards its eggs from egg predators, resulting in reduced predation of the eggs of the nonguarding species. The guarding species experiences costs in the form of intraguild predation of her offspring, and the addition of eggs to the guarding species therefore qualifies as brood parasitism. In the presence of egg predators, the brood parasite preferentially adds its eggs to those of the guarding host species, not to those of another, nonguarding mite species. This cuckoo behaviour comes with a cost for the parasite when egg predators are absent, and therefore only occurs when egg predators are present. Our findings emphasize the importance of the risk of egg predation as a factor driving facultative brood parasitism. Read the free Plain Language Summary for this article on the Journal blog.

Predatory mites (Acari: Phytoseiidae) on Vegetable Fields in Diyarbakır, Elazığ and Muş Provinces, Turkey

This study was conducted to identify predatory mite species on pepper, tomato, bean, cucumber, pumpkin, watermelon, melon, and eggplant plant leaves between 2018 and 2019 Diyarbakır, Elazığ, and Muş provinces. 1063 plant samples were collected and 676 of these samples which were observed with mite species. Predatory mite species were identified belonging to the Phytoseiidae family, which constitues 10.65% of 676 plant samples. The identified predatory mites were listed as Neoseiulus barkeri Hughes, Neoseiulus bicaudus Wainstein, Neoseiulus marginatus (Wainstein), Neoseiulus zwoelferi (Dosse), Neoseiulus sp., Phytoseius finitimus Ribaga, Proprioseiopsis messor (Wainstein), Typhlodromus (Anthoseius) bagdasarjani Wainstein and Arutunjan, Typhlodromus (Anthoseius) rhenanus (Oudemans) and Typhlodromus (Anthoseius) recki (Wainstein) in this study. Neoseiulus barkeri wasdetected as the most common species with 57.44% total number of individuals in the three provinces. The most detected host plants were Cucumis sativus L. at 60.59%; Solanum melongena L. (Family name) at 15.94% while the least detected vegetable was Capsicum annuum L. at 1.06% percentages.

Management of Panonychus ulmi with Various Miticides and Insecticides and Their Toxicity to Predatory Mites Conserved for Biological Mite Control in Eastern U.S. Apple Orchards

Panonychus ulmi (Koch) (Acari: Tetranychidae), commonly known as European red mite, is a polyphagous pest of various tree and small fruit crops, including apples. A field study was conducted to evaluate different pesticide options available for the management of P. ulmi, and their impact on the population of non-target predatory mite species complex consisting of Neoseiulus fallacis, Typhlodromus pyri, and Zetzellia mali in apple orchards. Pesticides were applied using a commercial airblast sprayer at the 3-5 mite/leaf recommended economic Integrated Pest Management (IPM) threshold or prophylactically in the spring ignoring IPM practices such as monitoring, reliance on biological control and economic thresholds. Effects on the motile and egg stages of P. ulmi were evaluated as were effects on the populations of predatory mites through frequent leaf counts during the season. We also recorded the subsequent overwintering eggs of P. ulmi from each pesticide treatment. The two prophylactic treatments containing a mixture of zeta-cypermethrin + avermectin B1 + 1% horticultural oil and abamectin + 1% horticultural oil provided effective control of P. ulmi population throughout the season without reducing predatory mite populations. In contrast, eight treatments applied at the recommended economic threshold of 3-5 mites/leaf were not effective in suppressing P. ulmi populations and most reduced predatory mites. Etoxazole had significantly higher number of overwintering P. ulmi eggs compared to all other treatments.

Foraging behaviors of Amblyseius swirskii Athias-Henriot and Euseius scutalis (Athias-Henriot) (Acari: Phytoseiidae) feed on the invasive pest, Eutetranychus orientalis (Klein) (Acari: Tetranychidae)

BackgroundRecent population outbreaks of citrus brown mite, Eutetranychus orientalis (Klein) (Acari: Tetranychidae), were observed in the Çukurova region, a region that supplies approximately 80% of total citrus production in Turkey. Therefore, to obtain preliminary data, regarding biological control of this pest, functional and numerical responses of two commonly found predatory mites, Amblyseius swirskii Athias-Henriot and Euseius scutalis (Athias-Henriot) (Phytoseiidae) in citrus orchards, to egg and protonymph stages of E. orientalis were determined under laboratory conditions.ResultsIn the experiments, six different prey densities (1, 5, 10, 20, 40 and 80) for each selected biological stage of the prey were provided to the predatory mite for 24 h. According to results, the proportion of prey consumed by A. swirskii decreased with increasing egg and protonymph stages of the prey densities. Similarly, the proportion of protonymph consumption of E. scutalis decreased with increasing prey densities, but egg consumption of the predator showed no discernible response to increasing densities. A. swirskii exhibited a type II functional response in both prey stages, whereas E. scutalis showed a type II response only for the protonymph stage of the prey. The attack rate (α) and the handling time (Th) varied between the biological stages and also predatory mite species. The highest α (0.066 h−1) and the lowest Th (0.536 h) values were determined when the A. swirskii was fed on protonymph stage of E. orientalis. The numerical response curves were found to be similar to those of Type II functional response. The efficiency of conversion of ingested food (ECI) of the both predatory mite species females decreased on both tested stages when prey density increased. The highest and the lowest average daily mean number of eggs laid by E. scutalis was found as 0.20 and 1.40 when it fed on eggs and protonymphs of its prey, respectively.ConclusionBoth predatory mite species were evaluated as potential and promising biological control agents in the sustainable control of E. orientalis in citrus orchards.

Side effects of abamectin and hexythiazox on seven predatory mites

Abstract Use of acaricides has become a common practice to control pests all over the world including Saudi Arabia. In spite of killing the targeted pests, such insecticides also effect growth of predatory mites. Present study has been conducted to evaluate the impact of two acaricides, abamectin and hexythiazox, on seven species of predatory mites. Standard solutions of abamectin (8.4% w/v) and hexythiazox (10% w/w) were purchased and prepared for direct spray. Acaricides were tested at three serial concentrations of recommended dose (RD), half of the recommended dose (HRD) and double the recommended dose (DRD). Trials were made on eggs, nymphs and adults of the seven species of predatory mites under laboratory conditions. Effect of the applied acaricides was determined one week after the application. The results of the study revealed that all doses of hexythiazox and abamectin are toxic to the nymphs and adults of all seven species of predatory mites but to the variable extent. Furthermore, it was observed that hexythiazox and abamectin reduced the percentage of egg hatching for all seven species of predatory mites. Hexythiazox was found to be more toxic than abamectin to all seven predatory mites. Higher mortality was recorded at DRD and RD, while minimum mortality was recorded at HRD. Acaricidal effect is less severe on hatching eggs than on immatures and adults of the predatory mites. Species vary in susceptibility to acaricides and in some populations resistance has been observed. Based upon this study, it is recommended that the frequent use of acaricides against phytophagous mites should be avoided and feasibility of biological control programs should be promoted to protect the environment, health of living individuals and the non-target organisms.

Review of the genus Gamasellodes Athias-Henriot (Mesostigmata: Ascidae) in Russia, with a description of a new species

A new predatory mite species of the genus Gamasellodes Athias-Henriot, 1961 (Mesostigmata: Ascidae), G. brevisetus sp. n., is described and illustrated based on morphological characters of adults collected from meadow soils of Eastern Europe, the Caucasus and Western Siberia. The spermatodactyl of the male chelicera is unique among the representatives of this genus, being a thin-walled goffered tube possessing a broad opening. Female spermathecal apparatus is of a laelapid-type, with two unpaired successive chambers. In addition, an identification key to all known Russian species of the genus is presented, including G. rectiventris Lindquist, 1971, which was recorded from Russia for the first time.

Re-assessing the pest status of Tetranychus evansi (Acari: Tetranychidae) on solanaceous crops and farmers control practices in Benin

This study was carried out 7 years after a first one conducted in 2013 as part of the policy of the Benin government to promote the vegetable production sector. Data collection was mostly based on a countrywide survey conducted in 25 municipalities throughout Benin, from August to December 2020. Farmers were selected based on their experience in cultivating solanaceous crops, and were interviewed to assess their perception about the severity of the spider mite Tetranychus evansi , the control method they used against this pest, and their knowledge about potential predators associated with the mites. Additionally, predatory mites associated with T. evansi in farmer fields were identified . All farmers recognized T. evansi to which they attributed local names depending on their ethnic group. They were also able to identify its damages on solanaceous crops. They indicated that outbreaks of T. evansi occurs at the end of the rainy season while their damages are more severe during the dry season. Production losses due to the mites were estimated by farmers to 27%, 24% and 22% respectively for tomato, African eggplant, pepper in the moderate damage case and 80%, 79%, 55% respectively for tomato, African eggplant and pepper in the severe damage conditions. To fight the mites, farmers generally apply heavy doses of chemical pesticides at high frequency. Pyrethroid and organophosphate compounds are the most frequently used pesticides. The only phytophagous mite recorded was T. evansi . A total of four species of predatory mites, all belonging to the phytoseiid family, were found associated with the pest on Solanaceous plants: Amblyseius swirskii, A. tamatavensis, Neoseiulus barkeri and N. longispinosus. This is the first report of the presence of N. longispinosus in Benin. Considering the high losses attributed to the pest, effective and sustainable management practices are necessary. • Importance of re-assessment of Tetranychus evansi status. • Importance of T. evansi damage on Tomato, African eggplant and pepper. • Importance of heavy chemical doses application. • Local predatory mites.

Prey stage preference and functional response of Neoseiulus striatus (Acari: Phytoseiidae) on Tetranychus urticae (Acari: Tetranychidae)

The two-spotted spider mite, Tetranychus urticae, is one of the most serious phytophagous mites affecting maize in China. Recently, a species of predatory mite, Neoseiulus striatus Wu (Acari: Phytoseiidae), was found on maize plants in Inner Mongolia. To understand the potential of N. striatus as a biocontrol agent agsinst T. urticae, prey stage preference of N. striatus for T. urticae and functional response of N. striatus to T. urticae were explored in a climate chamber set at 25 ± 1 °C, 60 ± 5% RH, and a 16:8 h (L:D) photoperiod. The immature stages (eggs, larvae and nymphs) of T. urticae were used to avoid the influence of oviposition of female adults on the experimental results. In the no-choice experiment, N. striatus consumed significantly more larvae than on the other prey stages of T. urticae. At same time, in the choice experiment, N. striatus also significantly preferred larvae, followed by eggs and then nymphs of T. urticae. Neoseiulus striatus displayed a type II functional response on all immature stages of T. urticae. The number of prey consumed by N. striatus increased with the increase in prey density. In contrast, the predation rate of N. striatus decreased with increasing prey density, indicating that the proportions of prey consumed by N. striatus were higher at lower prey densities. Meanwhile, the highest attack rate of N. striatus was recorded when it fed on larvae of T. urticae, whereas the shortest handling time of N. striatus was recorded when it fed on eggs of T. urticae. In conclusion, N. striatus appears to be a promising natural enemy against T. urticae, especially at low prey densities. Thus, releasing N. striatus at the early occurrence of T. urticae may be an efficient method for suppressing the population of T. urticae and prevent their establishment on maize.

Two new species of the genus Dactyloscirus (Acari: Prostigmata: Bdelloidea: Cunaxidae) from Sumatra, Indonesia, with a key to known species.

Two new species of predatory cunaxid mites belonging to the genus Dactyloscirus are described: Dactyloscirus sumatranus Corpuz-Raros and Naredo sp. n. and D. ladangjagung Corpuz-Raros and Lit sp. n. Both inhabit soil in corn fields in Sumatra Island, Indonesia. Dactyloscirus. sumatranus closely resembles D. dolichosetosus Den Heyer, 1979, but differs in having the basal half of chelicera strongly inflated, about four times thicker than in the distal half (vs. slender and gradually tapered), hysterosomal setae f1 and h1 at least twice as long as the anterior pairs c1-e1 (vs. only slightly longer), and famulus of tarsus I only ¾ the length of the closely associated asl (vs. longer). Dactyloscirus ladangjagung resembles D. hoffmannae Swift, 1996, but differs by the number of setae on some leg segments, namely, basifemora (5-5-3-2 vs. 5-5-3-1 sts) and tibiae (5-5-5-4 vs. 4-5-4-2 sts), and in having setae g4 the longest of genital setae (vs. setae g3). An updated key to 30 known Dactyloscirus species is provided.

Ecosystem services of soil predatory mites depend on a functional soil food web

Species of soil predatory mites feed on a diverse diet making them excellent candidates for conservation biological control programs. Free living nematodes (FLNs) are commonly found in soils at all trophic levels and serve as prey for many soil predatory mites (SPMs) in a functional soil food web. Here we present highlights of two case studies and the preliminary results of one ongoing study, all with the common aim of improving the conservation of soil predatory mites for the control of soil pests. In the first study, we used Macrocheles embersoni for housefly control (Azevedo et al., 2019), in the second, Stratiolaelaps scimitus for the control of the root knot nematode (RKN) Meloidogyne incognita (Azevedo et al., 2020), and in the third, we use frass of black soldier fly Hermetia illucens as an organic amendment for harnessing the local soil food web for the control of RKN. In the first two studies, complementing the diet of predatory mites with the FLN Rhabditella axei in their culture medium resulted in higher predator abundance and better biological control, compared to the negative control and the release of predators without FLNs and microbiota. In the third study the effect of the soil amendment on soil biota and RKN control differed among soils. We expect that soil amendments alter biocontrol efficacy, and that these effects are dependent on the biodiversity of soil biota as well as abiotic soil properties, and that caring for soils is a pre-requisite for successful conservation biological control.

Trophic links between soil predatory mites and nematodes as a key component of conservation biocontrol

Biological control is an important ecosystem service for soil and plant health and has been successfully exploited, especially through augmentative biological control programs, for above-ground agricultural pest control often using predatory mites of Mesostigmata. Similar success has not been achieved for below-ground systems. Predatory mites are an important part of soil food webs, in which they have a regulatory impact. While this is mediated by the predator on the prey, recent studies suggest that biocontrol efficiency can be enhanced in the mid to long term for generalist predators by the presence of complementary prey. In below-ground systems, nematodes are an important food source and numerous species of predatory mites in soil may prefer them. Thus, nematodes are a viable and accessible alternative prey for these natural enemies. Our aim was to review the studies on mite-nematode trophic interactions and how these interactions affect the regulatory activity of predatory mites in soil. We found ca. 170 publications reporting a predator-prey interaction. The majority of the studies were conducted in the laboratory (149 studies), but important correlations between nematode and mite densities have been observed in greenhouses and in the open field. Most reports involved free-living nematodes (FLN), followed by plant-parasitic nematodes (PPN) and finally animal-parasitic nematodes (APN). These reports are for Astigmatina, Endeostigmata, Prostigmata, Oribatida (non-Astigmatina) and Mesostigmata, the latter group being the one in which most nematophagous species are known. The family with the most reports of nematophagy is Ascidae (46 species), followed by Macrochelidae and Laelapidae (both with 30 species). In many cases, a positive effect on reproductive parameters and developmental times of mite species has been observed with a nematode-based diet, especially FLN. Although still scarce, studies on species of Laelapidae, Macrochelidae, Parasitidae and Rhodacaridae have shown that supplementing FLN in the diet can favor reproduction and development, even though preference may change at different stages of development. Also, recent studies have shown that some organic amendments can increase the density and diversity of mites, FLN or both, enhancing top down forces by predatory mites in the soil food web. Although some steps have been taken, future studies should focus on transferring laboratory research to field and semi-field conditions. For this, a multidisciplinary approach is essential.

Suitable areas of two introduced predatory mites and their interactions with one native predatory mite in China

Predatory mites were the second largest group of natural enemies, where some species have been commercialized and used worldwide for pest biological control. Two important predatory mite species Phytoseiulus persimilis and Neoseiulus cucumeris have been introduced to China for the control of mite and small insect pests in greenhouses and open fields. However, little was known about their suitable distribution range in China and their interactions with the native and commercialized predatory mites, making their application and commercialization difficult. 

Unveiling the diet of predatory mites through DNA metabarcoding—can abiotic factors affect prey detectability?

Despite the importance of predatory mites as biological control agents, the way that generalist species can maintain in agrosystems, the alternative prey they can feed on, the way they choose to eat one prey, or another are poorly known. For some phytoseiid predatory mite species, prey consumption has been characterized by lab tests (Cavalcante et al., 2015, 2017; Juan-Blasco et al., 2012; Oliveira et al., 2007). However, those approaches are sometimes difficult to perform, very time consuming and do not totally reflect interactions occurring in field conditions. New technologies that allow determining the diet of predatory mites in situ are highly desirable to supporting biological control programs. A promising avenue for deciphering the diet of predatory mites is offered by DNA metabarcoding. Although this approach has been used in the study of insects (Hosseini et al., 2008; Kaunisto et al., 2017; Paula et al., 2022), only starts to be applied to microarthropod biological control agents, as predatory mites (Navia et al., 2019). DNA metabarcoding was successfully applied to identify prey species of phytoseiid mites using group-specific primers. However, biotic and abiotic factors can affect the detectability of predatory mite preys through metabarcoding, as previously showed for studies using traditional molecular methods (=PCR Multiplex and Sanger sequencing) (Pérez-Sayas et al., 2015). This information is relevant to understanding the limits of using the methodology, to guide sample collection procedures, and to assure the correct interpretation of the results.

Arthropods associated with the lychee erinose mite, Aceria litchii (Acari: Eriophyidae) on lychee trees in Minas Gerais, Brazil.

Lychee fruit production (Litchi chinensis) has been threatened in many regions of the world where the presence has been reported of the litchii erinose mite, Aceria litchii (Keifer). This study aims to identify the arthropod community associated with A. litchii on lychee plants in Minas Gerais, Brazil, and to seek for potential natural enemies associated with this mite pest in this region. We sampled lychee leaves infested with A. litchii in commercial and non-commercial lychee orchards during seven consecutive months, covering the dry and wet seasons of the year. Arthropods found in association with A. litchii on lychee leaves were collected and identified. The results indicate that a great diversity and abundance of mites and hexapods are associated with A. litchii. A total of 985 and 1872 specimens of mites were identified in commercial and non-commercial areas, respectively, belonging to the families Cheyletidae, Cunaxidae, Eupodidae, Iolinidae, Stigmaeidae, Phytoseiidae, Tarsonemidae, Tenuipalpidae, Tetranychidae, Tryophtydeidae, Tuckerellidae, Tydeidae, Winterschmidtiidae and Xenocaligonellidae and the suborder Oribatida. Among them, Phytoseiidae was the most abundant and diverse family with a total of 11 species identified, in which Phytoseius intermedius was the most abundant predatory mite species collected. Minor specimens of hexapods were also been, belonging to the orders Collembola, Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, Psocoptera and Thysanoptera. The presence of a high community of predatory mites in association with A. litchii deserves attention and our results indicate that studies to test the potential of these species and the adoption of management practices that enhance this ecological service must be carried out to achieve satisfactory control of the lychee erinose mite in lychee plants.

Age-Stage, Two-Sex Life Table and Functional Response of Amblyseius orientalis (Acari: Phytoseiidae) Feeding on Different Nutrient Sources.

Amblyseius orientalis Ehara is a predatory mite that belongs to the family Phytoseiidae. It is mainly found in Jiangxi, Shanghai, Guangdong, and other areas of China. Although A. orientalis is a dominant predatory mite species in China and is also important for agriculture and biological control, not many studies have investigated it. Thus, research on A. orientalis is necessary. However, its application in biological control is hindered by the absence of techniques for the mass rearing of A. orientalis in captivity. We conducted experiments to determine the growth, development, reproduction, and functional response of A. orientalis in this study by indoor single-head rearing at 25 ± 1 °C, 65 ± 5% relative humidity, and a photoperiod of a 16 h:8 h light/dark cycle under laboratory conditions. The results of the age stage, two-sex life table showed that the individuals in the pollen + yeast and pollen + yeast + sucrose groups had significantly higher oviposition period, fecundity, net reproductive rate (R0), and gross reproduction rate (GRR) than those in the pollen group. The results of the function response showed that the pollen + yeast + sucrose group was the most favorable for captive breeding of A. orientalis and had the best predatory ability along with rejuvenation and recovery ability. The results of the study provided a theoretical basis for indoor rearing, propagation, and utilization of A. orientalis.

The effect of spider mite-pathogenic strains of Beauveria bassiana and humidity on the survival and feeding behavior of Neoseiulus predatory mite species

Predatory mites and invertebrate-pathogenic fungi have been used as biological control agents in a complementary way to suppress two-spotted spider mite (TSM) populations, which are a key pest of horticultural crops worldwide. However, their performance can be lowered by both biotic (e.g., intraguild interactions) and abiotic stress (especially relative humidity - RH). The present study evaluated the susceptibility of three predatory phytoseiid mite species in the genus Neoseiulus – N. californicus, N. idaeus, and N. barkeri – to infection by selected spider mite-pathogenic Beauveria bassiana strains as well as their predation capacity and resilience under simulated drought conditions. The two selected B. bassiana strains induced TSM mortality above 70 %. All three Neoseiulus mite species also showed susceptibility to both strains; however, N. barkeri was less susceptible to fungal infections than the other Neoseiulus species (with mortality < 65 % and without reduction of oviposition). All three Neoseiulus species were negatively affected by low RH conditions. Neoseiulus barkeri was the most affected with a drastic reduction in TSM egg consumption (about 40 %) and preventing the deposition of eggs by females. The egg consumption by N. californicus and N. idaeus was not affected by low RH conditions; however, both predatory mites reduced the number of eggs laid per female. Thus, the efficiency of the conversion of food into egg biomass for all three Neoseiulus species decreased under low RH conditions, dropping to zero for N. barkeri. We showed that the simultaneous use of B. bassiana and Neoseiulus had a detrimental effect on predatory mite survival and progeny, indicating the need for further development of new strategies which combine these biological control agents.

A new, broadly distributed species of predacious mites, Neoseiulus neoagrestis sp. nov., (Acari: Phytoseiidae) discovered through GenBank data mining and extensive morphological analyses

A new species of phytoseiid mites, Neoseiulus neoagrestis sp. nov., was described based on all ontogenetic stages and extensive comparison with types/vouchers of closely related species and a thorough analysis of GenBank data. Mite specimens were collected in an area at the eastern coast of the Black Sea of Russia and cultured. Molecular barcoding revealed a close match (100–99.25%) with several unidentified COX1 sequences from Canada. Both Canadian and Russian mites reproduced sexually and had consistent morphology, including the presence of gd2 gland pores, indicating that they belong to a single species, N. neoagrestis sp. nov. The presence of gd2 gland pores distinguishes N. neoagrestis sp. nov. from a closely related, parthenogenetic species N. agrestis (Karg), which lacks gd2 gland pores. Despite having an arguably negligible morphological difference, these two species were clearly distinct by COX1 sequences (19.95–22.01% K2P distances). We studied the ontogeny of N. neoagrestis sp. nov. and provided comparison with related Neoseiulus species. Furthermore, our examination of types of N. agrestis, N. salish, and N. striatus indicated that the latter two species are potential junior synonyms of N. agrestis.