Prey stage preference of Amblyseius paraaerialis (Acari: Phytoseiidae) on varied life stages of the spider mites Tetranychus urticae, Tetranychus macfarlanei and Oligonychus biharensis (Acari: Tetranychidae) and exploring the mass rearing possibilities of this predatory mite on alternative diets.

Spider mites Tetranychus urticae, Tetranychus macfarlanei and Oligonychus biharensis are considered to be highly polyphagous in nature and causes severe damage to a wide range of plants around the world. Amblyseius paraaerialis is an efficient phytoseiid predator of spider mites with a potential to survive on both natural and alternative diets. Evaluation of predatory potential and prey stage preference provides valuable information on the efficacy of the predatory species in controlling mite population. Feeding experiments were conducted on mulberry leaf discs under the laboratory conditions of 30 ± 2 °C and 70 ± 5% relative humidity (RH). After 24 h of feeding experiment, the adult female predator exhibited a significant preference in feeding towards the eggs of T. macfarlanei (42.6%) and the larval stages of T. urticae (46%) and O. biharensis (25.3%). The mass rearing possibilities of A. paraaerialis was tested by tracking and comparing the developmental duration of individual life stages on varied food sources like, honey, castor (Ricinus communis) pollen, honey-pollen mixture and mixed life stages of T. urticae. The predator was failed to complete its development on honey and pollen when supplied separately. However it was successfully developed on honey-pollen mixture and mixed life stages of T. urticae. The developmental studies unravelled a shortest developmental duration and an extended adult longevity and lifespan of A. paraaerialis when reared on the alternative diet, thus opened up the mass rearing possibility of the predatory species under laboratory conditions.

Morphological changes and ontogenetic development of Amblyseius eharai Amitai & Swirski (Acari: Phytoseiidae).

This paper describes the immature and mature characteristics of Amblyseius eharai Amitai & Swirski in detail to determine its morphological ontogeny based on laboratory-reared specimens. The main changes during ontogeny are as follows: the pronotal shield extends to j6 level and opisthosoma is unsclerotized in the larva; the dorsum has two shields in the protonymph, pronotal shield slightly expended comparing to that of the larva, and the opisthonotal shield smooth and weakly sclerotized. The podonotal and opisthonotal shields in the deutonymph are partially fused, and the dorsal shield is complete, covering almost the entire opisthonotum in adults in both sexes. There are nine pairs of dorsal setae in the larva, 14 pairs in the protonymph, and 19 pairs in both deutonymph and adult. In deutonymphs, gender could be distinguished by the number of setae in the area around the anal valves. In protonymphs, all dorsal, hypostomal setae, and the macrosetae of leg IV appear and are consistent with the subsequent stages. The development of morphological traits in the ontogeny of A. eharai may provide some basic knowledge to distinguish it from closely related species.

Redescription and new record of Odontoscirus nipponicus Shiba, 1985 (Bdellidae: Odontoscirinae) from China with a description of its ontogeny.

Odontoscirus nipponicus Shiba, 1985 is recorded from China and is redescribed; male, tritonymph, deutonymph, protonymph, and larva are described and illustrated for the first time. Morphological observations on the ontogeny of this species are also provided.

Molecular phylogeny of Phyllocoptes associated with roses discloses the presence of a new species.

There are few plant maladies as devastating as rose rosette, a disease caused by an eriophyoid -transmitted virus. Rosette annihilates roses across North America, and to date, there is a single verified vector of the virus, Phyllocoptes fructiphilus Keifer. In direct contrast to the importance of rose for the ornamental industry there is limited knowledge on the eriophyoids that inhabit roses in North America and even less information on their vectoring capacities. This study dissects the genetic diversity of the eriophyoid fauna in rosette-affected hotspots and provides evidence of the existence of an undescribed species named Phyllocoptes arcani sp. nov., that could potentially be a second vector of the rosette virus.

New findings of spinturnicid mites (Mesostigmata: Gamasina: Spinturnicidae) from the Caucasus.

The Caucasus is a large region in Eurasia consisting of four countries: Russia, Georgia, Azerbaijan, and Armenia. Although it is one of the biodiversity hotspots in the world, the bat ectoparasite fauna has been poorly studied. To promotionally fill in the gaps regarding bat ectoparasites, we conducted five field surveys on bats and their ectoparasites at nine localities within the region between April 2016 and March 2021. Eight species and subspecies of spinturnicid mites were recorded over the surveys: Eyndhovenia euryalis oudemansi, Spinturnix acuminata acuminata, S. emarginata, S. myoti, S. nobleti, S. plecotina, S. psi, and S. punctata. Among them, three species, Spinturnix emarginata, S. nobleti and S. punctate, are newly recorded from the Caucasus region, and one each of subspecies and species, Eyndhovenia euryalis oudemansi and S. plecotina, are newly recorded from Georgia. In addition, Myotis tschuliensis was recorded as a new host species of S. myoti.

First record of Eyndhovenia (Mesostigmata: Gamasina: Spinturnicidae) from Vietnam.

Eyndhovenia is one of the twelve genera of Spinturnicidae which are highly specialised parasites of bats. Previously known hosts of this genus comprised 17 species of Old World bats: Eptesicus serotinus, Hipposideros larvatus, Miniopterus schreibersi, Myotis blythi, M. emarginatus, Pipistrellus pipistrellus, P. gaisleri, Rhinolophus axillaris, R. blasii, R. clivosus, R. cornutus, R. euryale, R. ferrumequinum, R. hipposideros, R. megachyllus, R. mehelyi, R. rouxi. Within Asia, Eyndhovenia was only recorded from two countries, China and Thailand. Between 2018 and 2020, we conducted a series of bats surveys and recorded of this genus from intermediate horseshoe bat, Rhinolophus affinis, in Vietnam. The present study exhibits the new record in both parasitological and geographical aspects.

Molecular detection of vector-borne agents in ectoparasites and reptiles from Brazil.

Trombidiformes and Mesostigmata mites, as well as Ixodida ticks, infest ectothermic tetrapods worldwide, potentially acting as vectors of bacteria, viruses and protozoa. The relationship among ectoparasites, transmitted pathogenic agents (e.g., Borrelia spp., Coxiella spp., Hepatozoon spp., and Rickettsia spp.) and ectothermic hosts has been scarcely investigated. This research focuses on a large collection of Brazilian herpetofauna screened for the presence of arthropod ectoparasites and vector-borne microbial agents. Reptiles (n = 121) and amphibians (n = 49) from various locations were infested by ectoparasites. Following genomic extraction, microbial agents were detected in 81 % of the Acari (i.e. n = 113 mites and n = 26 ticks). None of the mites, ticks and tissues from amphibians yielded positive results for any of the screened agents. Blood was collected from reptiles and processed through blood cytology and molecular analyses (n = 48). Of those, six snakes (12.5 %) showed intraerythrocytic alterations compatible with Hepatozoon spp. gamonts and Iridovirus inclusions. Hepatozoon spp. similar to Hepatozoon ayorgbor and Hepatozoon musa were molecularly identified from seven hosts, two mite and two tick species. Rickettsia spp. (e.g., Rickettsia amblyommatis, Rickettsia bellii-like, Rickettsia sp.) were detected molecularly from four mite species and Amblyomma rotundatum ticks. Phylogenetic analyses confirmed the molecular identification of the above-mentioned microbial agents of mites and ticks related to snakes and lizards. Overall, our findings highlighted that the Brazilian herpetofauna and its ectoparasites harbour potentially pathogenic agents, particularly from the northern and south-eastern regions. The detection of several species of spotted fever group Rickettsia pointed out the potential role of ectothermic hosts and related arthropod ectoparasites in the epidemiological cycle of these bacteria in Brazil.

Biological control of mites by xerophile Eurotium species isolated from the surface of dry cured ham and dry beef cecina.

Some meat dry products, including dry cured ham and dry beef cecina, are cured in cellars at moderately cold temperature allowing the growth of a lawn of fungi on their surface. During the curing process, frequently these products became contaminated with fungivore mites of the Acaridae family that feed on fungal mycelium and spores. AIMS: The aim of this article is to study the possible biological control of mites by fungi that form part of the normal microbiota of these meat products. METHODS AND RESULTS: Some yellow/orange pigmented fungi growing on the ham surface decreased the proliferation of mites; therefore, we isolated from ham and cecina xerophilic yellow/orange coloured fungal strains that were identified as members of the genus Eurotium (recently reclassified as Aspergillus section Aspergillus). Using molecular genetic tools, we have identified 158 strains as Eurotium rubrum (Aspergillus ruber), Eurotium repens (Aspergillus pseudoglaucus) and Eurotium chevalieri (Aspergillus chevalieri). Two strains, E. rubrum C47 and E. rubrum C49, showed strong miticidal activity. The toxic compound(s) are associated with the formation of cleistothecia. In synchronized mite development experiments, we observed that all stages of the mite lifecycle were inhibited by the E. rubrum C47 strain. In addition, we searched for miticidal activity in 13 culture collection Eurotium strains isolated from different habitats, and found that only one, Eurotium cristatum NRRL 4222 (Aspergillus cristatus) has a strong miticidal activity. CONCLUSIONS: These fungal strains have proliferated on the surface of ham and cecina for decades, and possibly have acquired miticidal activity as a resistance mechanism against fungivores. SIGNIFICANCE AND IMPACT OF THE STUDY: Biological control of infecting mites by favouring growth of E. rubrun C47, in place of the normal mixed population of Aspergillus and Penicillium, is an attractive approach to control mite infestations.

An efficient high-welfare feeding device for assessing northern fowl mite interventions in vivo: an improved method for the identification of protective antigens/systemic acaricides/repellent effect.

The northern fowl mite (NFM), Ornithonyssus sylviarum, is an obligate hematophagous ectoparasite of domestic and wild birds, and it is an economic pest of laying hen in North America, China, India, Australia, Myanmar, and Brazil. Such an economically important pest remains neglected in many parts of the world, including Asian countries. Therefore, concerted action is required in both basic and applied research directed at the biology and control of this destructive pest. In the present study, we have developed a novel, high-welfare in vivo feeding capsule that would permit pre-screening of new interventions, repellency and deterrence effects of plant-derived products and other semiochemical compounds before proceeding to large-scale field experiments/bioassays, while the minimum number of animals is required to obtain results. Mites were fed on the birds through either a mesh or without a mesh. The average feeding rates of mites was significantly higher when fed directly on chickens, whereas 106 µm nylon mesh was the top-performing mesh when compared with 125 µm aperture nylon mesh. For optimal feeding, the feeding capsules contain NFM and are attached to the skin of the chicken's thigh for 6 h. This is a simple, reproducible, and easy approach and can be adapted to facilitate many aspects of bioassays.

Ultrastructure of the intestinal system in unfed larvae of Limnesia maculata (O.F. Müller, 1776) (Acariformes, Limnesiidae).

The intestinal system of unfed fresh-water mite larvae Limnesia maculata (O.F. Müller, 1776) (Acariformes, Limnesiidae) has been studied with transmission electron microscopy. The intestinal system is composed of the foregut, including the pharynx and the esophagus, the sac-like blind midgut and the excretory organ. The pharynx begins with the mouth covered by the labrum. The pharynx runs along the bottom of the gnathosoma and shows ventral dilators. No valves are expressed between the pharynx and the esophagus. The esophagus possesses strongly plicate walls and, before entering the midgut, passes through the brain. The sac-like midgut does not reveal a well-pronounced lumen, developed epithelium and separate lobes. It consists of the two cell types of endoderm origin mixed in the midgut volume. The first type - the vacuolated cells - does not possess Golgi bodies and lysosomal apparatus and shows electron-lucent vacuoles with a granular inclusion inside. These cells apparently do not take part in digestion of the embryonic yolk. The second type - the non-vacuolated cells - shows both, a well developed Golgi complex and large heterolysosomes, and obviously digests the embryonic yolk. Consequently, they may be attributed as specialized vitellophages. Nevertheless, both cell types may take part in formation of the definitive midgut epithelium. The sac-like thin-walled excretory organ is strongly dilated and contains the embryonic wastes in the form of electron-dense globules and birefringent particles. No muscle envelope surrounds the excretory organ. The embryonic wastes together with wastes accumulated during feeding may be evacuated from the organ only after completion of feeding. The excretory canal on this developmental stage is not connected with the excretory organ. It opens to the outside with a simple slit-like excretory pore. Before feeding, larvae have to pass the process of the post-molt development before their midgut would be ready to receive nutrients.

Temperature stress induces mites to help their carrion beetle hosts by eliminating rival blowflies.

Ecological conditions are known to change the expression of mutualisms though the causal agents driving such changes remain poorly understood. Here we show that temperature stress modulates the harm threatened by a common enemy, and thereby induces a phoretic mite to become a protective mutualist. Our experiments focus on the interactions between the burying beetle Nicrophorus vespilloides, an associated mite species Poecilochirus carabi and their common enemy, blowflies, when all three species reproduce on the same small vertebrate carrion. We show that mites compete with beetle larvae for food in the absence of blowflies, and reduce beetle reproductive success. However, when blowflies breed on the carrion too, mites enhance beetle reproductive success by eating blowfly eggs. High densities of mites are especially effective at promoting beetle reproductive success at higher and lower natural ranges in temperature, when blowfly larvae are more potent rivals for the limited resources on the carcass.

Mode of entry of secondary metabolites of the bacteria Xenorhabdus szentirmaii and X. nematophila into Tetranychus urticae, and their toxicity to the predatory mites Phytoseiulus persimilis and Neoseiulus californicus.

The bacterial metabolites in supernatants of Xenorhabdus species have acaricidal activity, but this mode of entry into mites has not yet been elucidated. Herein, we report on the possible mode of entry of Xenorhabdus szentirmaii and Xenorhabdus nematophila supernatants into Tetranychus urticae (Acari: Tetranychidae) adult females. We also assessed the toxicity of the supernatants against the developmental stages of the predatory mites, Phytoseiulus persimilis and Neoseiulus californicus (Acari: Phytoseiidae). Experiments were conducted at 25 ± 1 °C, 70 ± 5% relative humidity, and 16:8h light:dark conditions. Our data showed that the bioactive acaricidal compound is most effective (86.5 to 89% mortality) when the entire integument of T. urticae comes in contact with it compared to contact of the ventral side only (26.5-34%). Against P. persimilis and N. californicus at 6 days post-application (dpa), the eggs were not affected by the X. szentirmaii or X. nematophila supernatant, whereas mortality of the mobile stages (larva, protonymph, deutonymph, adult) was 18.5% to 39.2%. Overall, the predatory mites were less affected by the bacterial metabolites than T. urticae. We hypothesize that the differences in morphology such as longer legs and thicker cuticle, as well as the diet of the predatory mites, reduce the contact of the body parts to the supernatant-treated surfaces. We need to isolate, identify, and characterize the X. szentirmaii and X. nematophila metabolite(s) and demonstrate efficacy to pestiferous mites and safety to plants, non-target organisms and the environment before it can be used as an acaricide.

Molecular and biochemical characterization of enolase from Dermanyssus gallinae.

Enolase, a multifunctional glycolytic enzyme, is known to act as a plasminogen receptor in many species, involved in the pivotal processes such as motility, adhesion, invasion, growth, and differentiation of the parasites. Knowledge on the function of enolase from Dermanyssus gallinae is very limited. Here we report on the molecular cloning, enzymatic activity, tissue distribution and plasminogen binding activity of enolase from D. gallinae (DgENO). The full-length of cDNA was 1305 bp, specifying a peptide of 434 amino acids. Bioinformatics analysis showed that DgENO was highly conserved compared with a range of organisms, indicating the potentially similar functions in D. gallinae. A recombinant DgENO (rDgENO) protein was produced and characterized, it catalyzed the dehydration of 2-phospho-D-glycerate to phosphoenolpyruvate, the optimal pH was 7.5. Polyclonal antibodies were generated in mice and western blotting indicated that antiserum specifically recognized the native enolase in the somatic extracts from D. gallinae. Immunohistochemical staining of mite sections revealed that the distribution of DgENO was ubiquitous with high level in salivary gland, mite digestive tissues and fat bodies in D. gallinae. Expression level of DgENO was observed mostly in engorged adult mites. Moreover, ELISA binding assay showed that rDgENO could bind plasminogen, and lysine analog ε-aminocaproic acid significantly inhibited this binding activity, indicating that D. gallinae enolase is a receptor of plasminogen. The present study provided foundation for understanding of the biological functions of DgENO and its application in development of vaccines against D. gallinae.

The first finding of parasitic mite, Parasteatonyssus nyctinomi (Mesostigmata: Gamasina: Macronyssidae), in Namibia.

Sixty-four individuals of a macronyssid mite, Parasteatonyssus nyctinomi (Zumpt, Patterson 1951), were identified from Egyptian free-tailed bats Tadarida aegyptiaca (É. Geoffroy 1818) (Chiroptera: Molossidae) captured in the Kunene region of Namibia (southern Africa). This is the first report on P. nyctinomi in the country.

A sampling and estimation method for monitoring poultry red mite (Dermanyssus gallinae) infestation on caged-layer poultry farms.

BACKGROUND: The poultry red mite, Dermanyssus gallinae, is a serious problem in the laying hen industry worldwide. Currently, the foremost control method for D. gallinae is the implementation of integrated pest management, the effective application of which necessitates a precise monitoring method. OBJECTIVES: The aim of the study was to propose an accurate monitoring method with a reliable protocol for caged-layer poultry farms, and to suggest an objective classification for assessing D. gallinae infestation on caged-layer poultry farms according to the number of mites collected using the developed monitoring method. METHODS: We compared the numbers of mites collected from corrugated cardboard traps, regarding with length of sampling periods, sampling sites on cage, and sampling positions in farm buildings. The study also compared the mean numbers of mites collected by the developed method with the infestation levels using by the conventional monitoring methods in 37 caged-layer farm buildings. RESULTS: The statistical validation provided the suitable monitoring method that the traps were installed for 2 days on feed boxes at 27 sampling points which included three vertical levels across nine equally divided zones of farms. Using this monitoring method, the D. gallinae infestation level can be assessed objectively on caged-layer poultry farms. Moreover, the method is more sensitive than the conventional method in detecting very small populations of mites. CONCLUSIONS: This method can be used to identify the initial stages of D. gallinae infestation in the caged-layer poultry farms, and therefore, will contribute to establishment of effective control strategies for this mite.

Low-temperature storage of the poultry red mite, Dermanyssus gallinae, facilitates laboratory colony maintenance and population growth.

The poultry red mite, Dermanyssus gallinae, is currently the most common ectoparasite affecting egg-laying hens. Since continuous culture of D. gallinae on birds is a biologically and economically costly endeavour, storage techniques for mites are urgently needed. Effects of temperature on adult and nymph survival were first studied to optimize storage conditions. Then, fecundity of D. gallinae was studied after mites were stored at optimal storage conditions. Results showed the survival rates of protonymphs (42.11%), deutonymphs (8.19%) and females (19.78%) at 5°C after 84 days were higher than those at 0, 25 and 30°C. Thereafter the fecundity and the capability of re-establishing colonies of D. gallinae were evaluated after they were stored for 40 and 80 days at 5°C. After storage, the mean number of eggs showed no statistical difference between treated (5°C for 40 or 80 days) and control groups (25°C for 7 days), while the hatching rates of eggs were in all cases above 97%. The dynamic changes of mite populations and egg numbers showed similar trends to the control group after the stored adult or nymph mites were fed on chicks. Dermanyssus gallinae can be successfully stored at 5°C for 80 days with no interference with the fecundity of mites, and the stored mites could re-establish colonies successfully. Adults and nymphs were two main stages with capability for low temperature storage. These results suggest that low temperature storage is a viable option for colony maintenance of D. gallinae under laboratory conditions.

Evidence of trans-generational developmental modifications induced by simulated heat waves in an arthropod.

Heat waves are considered to pose a greater risk to arthropods with their limited thermoregulation abilities than the increase of mean temperatures. Theoretically, within- and trans-generational modifications may allow populations to keep pace with rapidly occurring heat waves. Here, we evaluated this assumption using individuals of predatory mite Amblydromalus limonicus from the F1 and F2 generation, which were exposed to summer or simulated heat wave conditions during juvenile development. Independent of generation, survival and male body size were insensitive to heat waves. Heat stress elongated juvenile development of F1 males and females, and lowered the F1 female size at maturity indicating non-adaptive within-generational effects. Trans-generational modifications speeded up the development of F2 males and females and resulted in larger body size of F2 females deriving from the heat wave-experienced F1 generation. Faster F2 development should be adaptive, because it reduces the exposure time to heat waves and promotes an early beginning of mating activities. Being large at extreme high temperatures maybe a benefit for the F2 females, because large individuals are less vulnerable to dehydration and overheating. Thus, the potential fitness loss from reduced F1 growth should be compensated by increased fitness in the F2 indicating adaptive trans-generational modifications.

New Species of the Genus Periglischrus (Acari: Spinturnicidae) from Monophyllus Bats (Chiroptera: Phyllostomidae) in the West Indies, Including a Morphometric Analysis of Its Intraspecific Variation.

The discovery of a new species, Periglischrus empheresotrichus, was determined through a review of museum collections, as well as a field survey of ectoparasites of island bats. This new species parasitizes on two bat species of the genus Monophyllus Leach, the Greater Antillean Long-tongued bat Monophyllus redmani Leach and the Lesser Antillean Long-tongued bat Monophyllus plethodon Miller. The female, male, deuthonymphs, and protonymph are described and illustrated. P. empheresotrichus n. sp. has an insular distribution, we evaluated the morphological variation of the adult populations, and concluded that intra-specific variation is correlated both with host species and locality (island) in the West Indies.

Genomic insights into mite phylogeny, fitness, development, and reproduction.

BACKGROUND: Predatory mites (Acari: Phytoseiidae) are the most important beneficial arthropods used in augmentative biological pest control of protected crops around the world. However, the genomes of mites are far less well understood than those of insects and the evolutionary relationships among mite and other chelicerate orders are contested, with the enigmatic origin of mites at one of the centres in discussion of the evolution of Arachnida. RESULTS: We here report the 173 Mb nuclear genome (from 51.75 Gb pairs of Illumina reads) of the predatory mite, Neoseiulus cucumeris, a biocontrol agent against pests such as mites and thrips worldwide. We identified nearly 20.6 Mb (~ 11.93% of this genome) of repetitive sequences and annotated 18,735 protein-coding genes (a typical gene 2888 bp in size); the total length of protein-coding genes was about 50.55 Mb (29.2% of this assembly). About 37% (6981) of the genes are unique to N. cucumeris based on comparison with other arachnid genomes. Our phylogenomic analysis supported the monophyly of Acari, therefore rejecting the biphyletic origin of mites advocated by other studies based on limited gene fragments or few taxa in recent years. Our transcriptomic analyses of different life stages of N. cucumeris provide new insights into genes involved in its development. Putative genes involved in vitellogenesis, regulation of oviposition, sex determination, development of legs, signal perception, detoxification and stress-resistance, and innate immune systems are identified. CONCLUSIONS: Our genomics and developmental transcriptomics analyses of N. cucumeris provide invaluable resources for further research on the development, reproduction, and fitness of this economically important mite in particular and Arachnida in general.

The Investigation of Prevalence of Demodex spp. in University Students: The Case of the Faculty of Health Sciences

Objective: The aim of this study was to determine the prevalence of Demodex spp. in college students, mostly adolescent individuals. Methods: A questionnaire including questions about the risk factors of Demodex spp. was administered to college students. Samples were taken with Standard Superficial Skin Biopsy method and examined under light microscope. Results: Presence of Demodex spp. was detected in 160 (42.7%) students out of 375 totally; 126 out of 291 nursing students (43.3%) and 34 out of 84 midwifery students (40.5%). It was detected in 47.3% of males and 40.2% of females. There was a statistically significant difference in terms of the prevalence of Demodex spp. between those who used foundation cream/make-up products and those who did not, and between those who removed hair and those who did not (p<0.05). There was no relationship between other variables and Demodex spp. prevalence. Conclusion: It is concluded that Demodex spp. is very common among college students in Kars. Dermatologists should also consider the existence of Demodex spp. in the etiology and pathogenesis of dermatoses which develops in the facial region of individuals in this group of age.