Experimental and Applied Acarology最新文献

Acari is a diverse group of arthropods that include well-known parasites of animals. Rodents, particularly, serve as common hosts of mites and ticks, transmitting pathogens to domestic animals and humans. Understanding the ecological dynamics between parasites and rodent hosts is crucial for ecosystem management. Due to limited knowledge about the life history of ectoparasites in wild mouse nests, we collected four nests of Apodemus speciosus, the most common rodent species in the wild areas of Japan, along with soil samples near the nests to study arthropod communities. Mites overwhelmingly populated the mouse nests, comprising approximately 90% of all arthropods, while both mites and collembolans were prevalent in soil. Various species identified in our study, such as those from the families Laelapidae, Pygmephoridae, Cheyletidae, Trombiculidae, Glycyphagidae, and Thyrisomidae align with known ectoparasites or species found in the nests of other rodent species, but most parasitic species were never collected in the surrounding soil except for trombiculids. The dominance of mites in mouse nests suggests selective preference for inhabiting these host environments, although the exact reasons driving this dominance remain unclear. Further investigations into the food web within mouse nests will aid in characterising faunal composition and understanding the ecological interaction among rodents, mites, and other nest symbionts.

The genus Eustigmaeus Berlese, 1910 represents the unique phytophagous group within the superfamily Raphignathoidea. Four species within this genus have been known to inhabit mosses and feed on them as larvae, nymphs, and adults. However, the interactions with mosses have remained poorly understood. In order to reveal the diversity and host-plant use of the moss-feeding species, we conducted an extensive field study in Japan. This study revealed an array of moss-feeding species inhabiting various moss species, with 10 morphologically distinctive species newly documented in Japan. Through DNA barcoding based on cytochrome c oxidase subunit I (COI) sequences, these morphospecies were recovered as distinct entities. Notably, the host-plant use of four species was elucidated. Among these, Eustigmaeus sp. 9 exhibited polyphagy, while three species (Eustigmaeus spp. 1-3) demonstrated varying degrees of host specificity, each using moss species from the Hypnales, Philonotis, and Dicranidae, respectively. While a few moss-feeding species were frequently found in the same geographic area, more than one species rarely co-occurred within the same moss colonies. Eustigmaeus offers a unique study system, with its diverse moss-feeding species and indications of specific host plant use. Consequently, the moss-feeding Eustigmaeus serves as a valuable model for exploring the macroevolutionary patterns underlying diversification in moss-feeding arthropods.

There is limited knowledge about tick diversity in the Amazon region. Here, we survey small terrestrial mammals for tick infestation at the Rio Pardo settlement, Amazonas State, Brazil. Sampling included rainy and dry seasons and four ecotones (primary forest, forest in regeneration, field crops and households). Each animal was inspected for ticks, which, if present, were placed in 70% alcohol and identified. Parasitological indexes were calculated and the presence/absence of ticks on hosts was tested for possible associations with independent variables (ecotone, host sex, host order, host family, host age and season). A total of 208 small mammals were captured, 47 individuals (10 species) in the primary forest, 124 (15 species) in the forest in regeneration, 11 (7 species) in the field crops, and 26 (4 species) in the households. A total of 14 small mammals were infested by ticks (overall prevalence: 6.7%; 95% CI: 3.72 - 11.04%), which consisted of 51 specimens that were identified into four species, as follows: Amblyomma humerale (32 nymphs); Ixodes luciae (6 females); Amblyomma coelebs (1 nymph); and Ornithodoros mimon (1 larva). In addition, 11 larvae were retained as Amblyomma spp. Only host order showed association (P = 0.002) with tick infestation, with marsupials 5.5 times more infested than rodents. Our record of O. mimon on D. marsupialis is the first on this host species, and the first record of a Argasidae tick in the Brazilian state of Amazonas. To the best of our knowledge, this is the first study that actively screened free-living terrestrial small mammals and provided data on prevalence, mean intensity and mean abundance of tick infestations in the Brazilian Amazonas state.

This study explores sustainable agricultural practices by examining the role of organic materials in enhancing native predatory mites for controlling spider mites in apple orchards. Developing techniques to conserve indigenous natural enemies is vital for sustainable agricultural production. Phytoseiid mites can control spider mites, which are among the most significant pests in apple production. To conserve phytoseiid mite populations, it is important to identify alternative prey and to determine their role in phytoseiid mite proliferation. We demonstrated that the concurrent use of specific organic fertilizers and coconut husks can increase prey Tyrophagus mites, thereby enhancing phytoseiid mite density. Our research was conducted using sticky traps at the Miyagi Prefectural Agriculture and Horticulture Research Center in Japan. The occurrence of Tyrophagus mites was significantly correlated with the occurrence of phytoseiid mites in 2 years. In laboratory experiments, the use of organic fertilizers increased the density of Tyrophagus mites by 83 × within 4 weeks. Several species of phytoseiid mites were able to lay between 0.25 and 1.03 eggs per day per female by preying on Tyrophagus larvae. A 2-year field survey revealed that the use of organic fertilizers more than doubled the density of phytoseiid mites on apple leaves, likely through promoting Tyrophagus mite proliferation on the ground. These results highlight the potential of organic fertilizers not only to enhance soil nutrients, but also to boost phytoseiid mite populations, thereby contributing to more sustainable apple production.

Phytoseiid predatory mites are one of the most important groups of biocontrol agents, commonly used in biological control. The ability to produce these predatory mites economically, at high density on cheap factitious food sources, is a major contributor to their success. Astigmatid mites are the most widely used factitious food for this purpose. In this study, we investigated the potential application of the leaf-dwelling astigmatid mite Czenspinskia transversostriata (Oudemans) (Acari: Winterschmidtiidae) as a prey mite in biological control. We tested whether C. transversostriata is a suitable food source for the predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae), both in the laboratory and on cucumber plants. Based on a reproduction trial, C. transversostriata proved to be an equally good food source compared to both pollen of Typha angustifolia L. (Poales: Typhaceae) and a frequently used prey mite Carpoglyphus lactis L. (Acari: Carpoglyphidae). In a pre-establishment trial on cucumber plants, populations of A. swirskii reached equally high densities when supplemented with C. transversostriata, compared to C. lactis. Lastly, we show that C. transversostriata is capable of feeding and reproducing on powdery mildew growing on cucumber plants, thereby slowing down the development of the pathogenic fungus. Results derived from this study show that C. transversostriata may have multiple potential applications in biological control programs.

Vegetation cover has been consistently reported to be a factor influencing soil biota. Massive spreading of invasive plants may transform native plant communities, changing the quality of habitats as a result of modification of soil properties, most often having a directional effect on soil microorganisms and soil fauna. One of the most numerous microarthropods in the litter and soil is Acari. It has been shown that invasive plants usually have a negative effect on mites. We hypothesized that invasive Spiraea tomentosa affects the structure of the Uropodina community and that the abundance and species richness of Uropodina are lower in stands monodominated by S. tomentosa than in wet meadows free of this alien species. The research was carried out in wet meadows, where permanent plots were established in an invaded and uninvaded area of each meadow, soil samples were collected, soil moisture was determined and the mites were extracted. We found that Uropodina mite communities differed in the abundance of individual species but that the abundance and richness of species in their communities were similar. S. tomentosa invasion led primarily to changes in the quality of Uropodina communities, due to an increase in the shares of species from forest and hygrophilous habitats. Our results suggest that alien plant invasion does not always induce directional changes in mite assemblages, and conclude that the impact of an alien species on Uropodina may cause significant changes in the abundance and richness of individual species without causing significant changes in the abundance and diversity of their community.

Most published data on mite infestation rates in semi-arid regions have been collected over only 3 or 4 months during a specific period of the year. Therefore, the aim of this study was to observe parasite-host dynamics of hygienic and non-hygienic Africanized bee colonies considering environmental factors that may influence Varroa destructor mite infestation rates in a semi-arid region. To this end, the brood puncture method was applied to 37 colonies, forming two groups, namely G1, encompassing 16 hygienic colonies, and G2, comprising 21 non-hygienic colonies. After forming the groups, 300 worker bees from each colony were examined monthly for mite infestations and the data were correlated with climatological records. The monthly infestation average was considered low, below 10%, except in November, when it reached 12.19% ± 6.45. No statistically significant difference was observed for inter-group infestation rates (P > 0.05). When mite infestation rates were associated with climatic variables, they were linked to colony losses (32%) due to swarming. No significant correlations between hygienic behaviour and parasite infestation rates were noted. Nonetheless, these results support the idea that there is no need to apply acaricides for V. destructor control in Brazil.

We collected 56 specimens of Laelaps chini from the endemic Hengduan Mountain rat species (Eothenomys miletus) and obtained the first complete mitochondrial genome of L. chini by next-generation sequencing (NGS). The L. chini mitogenome is 16,507 bp in size and contains 37 genes and a control region of 2380 bp in length. The L. chini mitogenome has a high AT content and a compact arrangement with four overlapping regions ranging from 1 to 2 bp and 16 spacer regions ranging from 1 to 48 bp. We analyzed 13 protein-coding genes of L. chini mitogenome  and found that protein-coding genes in the L. chini mitogenome preferred codons ending in A/U and codon usage pattern was mainly influenced by natural selection. Cox1 has the slowest evolution rate and cox3 has the fastest evolution rate. We combined the mitochondrial genome of eight species of gamasid mites in the superfamily Dermanyssoidea from Genbank and the L. chini mitochondrial genome to analyze its rearrangement patterns and breakpoint numbers. We found that the L. chini mitogenome showed a novel arrangement pattern and nine species of gamasid mites in the superfamily Dermanyssoidea, which have been sequenced complete mitochondrial genomes to date, all showed different degrees of rearrangement. Laelaps chini, Echinolaelaps echidninus and Echinolaelaps fukinenensis were closely related species based on genetic distance and phylogenetic analyses. Notably they are clustered with Varroa destructor of the family Varroidae, suggesting that the family Varroidae is more closely related to the family Laelapidae, but more data are needed to test whether Varroa can be classified under the family Laelapidae. The L. chini mitogenome is the first complete mitochondrial genome for the genus Laelaps, and contributes to further exploration of the mitochondrial gene rearrangements and phylogeny for the superfamily Dermanyssoidea.

Tomato crops are attacked by several pests, including mites. While the main predatory mites are not effective enough to control mite pests, recent studies have shown encouraging results with the European endemic phytoseiid Typhlodromus (Anthoseius) recki. The first objective of the study was to assess the ability of this species to disperse along the tomato stem, considering six genotypes of Solanum lycopersicum, S. peruvianum and S. cheesmaniae with contrasted trichome numbers and types of stem trichomes, accuratetly characterised in a previous study. The second objective was to determine how predator morphological traits can explain dispersal along the tomato stem. For this, ambulatory dispersal ability of females (stem crossing rate success, hesitation and escape behavior, mobility periods) was tested in lab conditions on the eight Solanum genotypes, at four period of time after the predator introduction (10, 25, 55 and 100 min), with a video observation of 5 min at each period. The females were then mounted on slides and body length and width (at the fore hind, middle and back parts) measured. No effect of the tomato genotypes was observed on the dispersal ability of the predator. However, specimens that succeeded in crossing the stem, had a higher percentage of mobility time (79.36%) than those that failed (43.60%). Furthermore, body width at midbody (DSW2) and dorsal shield length (DSL) were negatively correlated with dispersal ability. The mean DSL and DSW2 of the females that succeed to cross were 342.3 and 160.9 μm, respectively vs. 345.6 and 164.9 μm, for females that did not succeed. This suggests that the more slender and relatively small the specimens, the more are mobile and able to successfully cross the stem. The number of glandular trichomes type (GT) VI and to a lesser extent GT I and IV, and non-glandular trichomes (NGT) II&III appear to limit dispersal. The GT VI seems to have a repellent effect. On the opposite, the number of NGT V were positively correlated with high mobility and stem crossing rates. Assuming that the main barrier to biological control efficiency is dispersal along tomato stems, these preliminary results should have implications for biological control success. The proportion of mites with 'optimal dimensions' appears to be low and further studies should be undertaken to better assess the proportion of mites with such ideal dimensions in different populations and also to determine whether these morphological traits are associated with different feeding abilities and/or abiotic conditions.