Experimental and Applied Acarology最新文献

The chelal moveable digit patterns of seventeen free-living astigmatan mite species commonly found in bird nests are decomposed into functional groups using the scoring of observed asperities in order to explain the mites' coexistence in that commensal community. Type 'A' (tearing hook-like) and Type 'B' (nibbling) moveable digit morphotypes are found and the default durophagous 'Bauplan' of the mastication surface is described in great detail. The angles of mastication surface features are important and suggest that asperities are adapted to handle aggregate material. The mites' cutting and crushing moveable digit is asymmetrically designed anterior→posterior. Stochastically the mastication surface of the moveable digits of bird nest astigmatans map between International Roughness Grade Numbers N5 to N7 suitable for fine grinding. Various gripping and bladed adaptations for browsing, scooping and scraping are highlighted. Miniaturisation reduces the opportunity for trophic design space differentiation. Examples of underbite suitable for levering up material are found. Blunt and shallow features (i.e., 'pads') may be suitable for contact with and the gripping of compliant or wetted material. The function of digit tips is discussed. Aleuroglyphus ovatus is a crusher. Chortoglyphus arcuatus is a chewer. Some glycyphagid moveable digits approximate saw designs. Acarus farris is highly variable around a plesiomorphic form. The differentiated surface of Tyrophagus putrescentiae proximal to the condyle adapted for specialised gleaning is confirmed. Some species have a derived form proximally with a 'latch' comprised of an almost right angled zenith tooth and a very strong 'pocketed' gullet just before the end of the mastication surface for 'snapping' material. The detailed pattern of gullets is more nuanced across species than the pattern for teeth. Rhizoglyphus robini showed adaptations to deal with plant material. Dermatophagoides pteronyssinus is designed unusually. Nematophagy is discussed. Of the taxa reviewed, it only remains unclear how Tyrophagus palmarum and Tyrophagus similis morphologically avoid direct trophic competition in this habitat.

Many chemical acaricides have been used to mitigate the detrimental effects of Haemaphysalis longicornis. However, the excessive use of chemical acaricides may facilitate the development of resistance in H. longicornis. Larval packet tests (LPTs) were conducted on larvae aged 14-21 days collected from 10 counties in China to evaluate the effectiveness of different acaricides, including cyhalothrin, cypermethrin, deltamethrin, amitraz, and fipronil. Additionally, genomic DNA was extracted from tick samples collected from 14 counties, and partial fragments of the voltage-gated sodium channel (VGSC), beta-amino-oxidoreductase (β AOR), and gamma-aminobutyric acid (GABA)-gated chloride channel genes were amplified via PCR. According to the LPT findings, it can be inferred that ticks from all localities exhibited resistance to at least three different acaricides. Multidrug resistance to five acaricides was detected in 40% of the samples, including those from Liaoning (LYG), Hebei (HZY), Henan (HSY), and Hubei (HSG) Provinces. The resistance factors for cyhalothrin, cypermethrin, deltamethrin, amitraz, and fipronil ranged from 2.71-9.57, 1.14-10.4, 0.80-24.2, 5.2-56.97, and 4.12-41.17, respectively. Hence, the resistance levels to the different acaricides ranged from susceptible (S) to level IV. Level IV resistance was observed only for fipronil and amitraz. Despite substantial resistance, no nonsynonymous mutations in the VGSC or β AOR genes were detected. However, one novel nonsynonymous mutation (M295L) in transmembrane 2 (TM2) of the GABA-gated chloride channel gene, which may have led to conformational changes in this channel, was detected in ticks from Shandong Province (SQL). In this study, LPTs were used to evaluate the effects of various acaricides on H. longicornis, and the findings revealed that this tick species is resistant to many acaricides. This study provides a foundation for the development of preventative and control measures against H. longicornis.

Aculus fockeui (Nalepa and Trouessart) is among the most economically significant pest mite species within the superfamily Eriophyoidea. In traditional taxonomy, A. fockeui was considered a single, oligophagous species, initially described on European plum and later reported on around 17 plant species within the genus Prunus. Cryptic speciation is common on eriophyoid mites with a small, morphologically simplified body. Given the limitations of conventional taxonomic methods in resolving cryptic species, integrating morphometric and molecular data is essential for accurate differentiation. Fifteen populations of A. fockeui collected from five different host plant species were analyzed using morphometrics in combination with the nucleotide sequences from the mitochondrial COI gene and the nuclear D2 region of the 28S rDNA. The results of both morphometry and molecular analyses were consistent and supported the hypothesis that the A. fockeui complex comprises multiple cryptic lineages. The substantial divergence in mtCOI sequences, compared to the considerably lower variability in the nuclear 28S D2 region, indicates a relatively recent evolutionary divergence among these lineages. The results obtained in this study support the hypothesis that A. fockeui represents a complex of cryptic species.

The citrus red mite (CRM), Panonychus citri (McGregor) (Acari: Tetranychidae), has expanded its range from southern China to colder regions in northern China, where low winter temperatures pose a critical survival challenge. Understanding its cold tolerance is important for predicting future distribution and dispersal patterns in northern China. However, the cryobiology of CRM remains poorly characterized. This study investigated three key aspects: (1) supercooling points (SCPs) of adult females, (2) lethal low temperatures for eggs and adult females under acute cold exposure and (3) the effects of cold acclimation (20 °C for 1-3 generations) and rapid cold hardening (4 °C for 2 h) on adult female cold tolerance. Results showed that the average SCP of adult females was - 20.66 ℃. Eggs exhibited significantly stronger cold tolerance than adult females. The lethal temperature causing 50% mortality (LT₅₀) was expected as -17.70 °C for eggs and - 7.58 °C for adult females after 2 h exposure. Notably, 6.03% of eggs survived 5 h at -31 °C, whereas all adult females died within 1 h at -12 °C. Both rapid cold hardening and multi-generational cold acclimation significantly enhanced adult female cold tolerance. Adult females were chill susceptible, and their cold tolerance could not be measured by SCP. These findings provide crucial physiological benchmarks for CRM. However, accurately forecasting its northward expansion requires future studies that integrate these laboratory data with field validation and modeling of ecologically relevant temperature regimes.

Anhui Province in China bears the highest burden of Severe Fever with Thrombocytopenia Syndrome (SFTS) nationwide; however, comprehensive surveys of tick vectors remain limited. We aimed to characterize tick species composition and to evaluate spatial patterns of vector distribution across SFTS-endemic areas in the province. In this study, a combined morphological and molecular approach was utilized for tick identification. Ticks were initially identified based on their morphological characteristics. Subsequently, gene fragments of the large subunit ribosomal RNA (16 S rRNA) and the cytochrome c oxidase subunit I (COI) were amplified to confirm species identification. A total of 3504 ticks were collected, including 2021 larvae (57.68%), 662 nymphs (18.89%), 677 females (19.04%), and 144 males (4.11%). A total of 1483 tick specimens (including nymphs and adults) were identified: Haemaphysalis longicornis was the most prevalent species (account for 71.07%), followed by Rhipicephalus sanguineus and Haemaphysalis flava. In total, 13 tick species from five genera were identified, seven of which-Haemaphysalis campanulata, Rhipicephalus turanicus, Haemaphysalis doenitzi, Haemaphysalis formosensis, Haemaphysalis yeni, Dermacentor steini, and Amblyomma testudinarium-represented new records for Anhui. The relative abundance of H. longicornis exhibited significant spatial heterogeneity (χ²=483.332, P < 0.001). Notably, in areas with high incidence of SFTS, the prevalence of H. longicornis was marked higher (88.39%, 95% CI: 86.41%-90.36%) compared with regions with low SFTS incidence (28.12%, 95% CI: 23.11%-33.12%) and non-case regions (44.16%, 95% CI: 36.22%-52.09%). In the areas with high incidence of SFTS, the infection rate and tick density of the external environment and animals were higher than those in the areas with low incidence and no cases. Phylogenetic analysis based on 16 S rRNA gene showed that the tested samples clustered within their respective GenBank species. Within the genus Haemaphysalis, H. longicornis exhibited closer relationships with H. hystricis and H. doenitzi. In the genus Rhipicephalus, R. turanicus was closely related to R. sanguineus. COI analysis indicated geographical differentiation in H. longicornis populations from Jinzhai and Qimen.This study characterizes the ixodid tick fauna in Anhui Province and reports several newly documented species. These findings highlight the need for enhanced surveillance of tick vectors and pathogen monitoring to support effective SFTS prevention and control.

The fig mite Aceria ficus (Cotte, 1920) (Acari: Eriophyidae) is a serious pest and virus vector of fig trees and the damage caused by this mite can significantly reduce fruit yield and quality. Environmental temperature, being a significant abiotic factor, is essential in pest biology and development and must be considered in pest management strategies, as it highly affects the population of these ectothermic arthropods and may worsen the pest status of a species. In this study, different life history traits of the fig mite were assessed at three constant temperatures (22, 26, and 30 °C) on fig leaves. All juvenile stages of the mite showed faster development as the temperature increased from 22 to 30 °C. Female development took the longest at 22 °C, lasting 27.21 days, followed by 26 °C with 24.1 days, and was shortest at 30 °C with 21.14 days. The highest fecundity (20.32 eggs/female) and oviposition period (11.97days) were obtained at 30 °C, whilst the lowest were observed at 22 °C (14.66 eggs/female, and 10.12 days). Furthermore, the highest net reproductive rate (R₀) and intrinsic rate of increase (r) were recorded at 30 °C (9.87 eggs/individual and 0.176 day^-1, respectively). These results indicate that the optimal temperature for the growth of the fig mite population is approximately 30 °C. They have implications for managing this mite vector and can be used in developing pest management strategies or predicting the population growth and dynamics of A. ficus on fig trees.

Soybean is an important economic crop, widely used in food, feed and energy fields. Tetranychus turkestani (Ugarov & Nikolskii) (Acari: Tetranychidae) is one of the major pests of soybean in Xinjiang, seriously affecting the yield and quality of soybean. To clarify the adaptability of T. turkestani to soybean varieties and provide information for further research and control, this experiment adopted the age-stage, two-sex life table method under indoor constant temperature conditions to analyze the growth, development, and fecundity of T. turkestani on 6 high-yield and main cultivated soybean varieties in Xinjiang (Xindadou 23, Xindadou 8, Xindadou 26, Longken 324, Xinzhendou 1, and Xindadou 25). In general, the generation duration of T. turkestani was the longest on Longken 324 (8.476 ± 0.084 days), and the oviposition period was the longest on Xindadou 25 (20.848 ± 1.034 days). In addition, the fecundity per female (184.745 ± 7.401 eggs) and intrinsic rate of increase (0.370 ± 0.009 days^- 1) on Xindadou 8 were significantly higher than those on other varieties; the intrinsic rates of increase on Xindadou 25 (0.316 days^- 1) and Longken 324 (0.323 days^- 1) were the lowest. Therefore, T. turkestani has the lowest adaptability to Xindadou 25 and Longken 324. It has the highest adaptability to Xinzhendou 1, Xindadou 8 and 23. In years when the occurrence of T. turkestani is predicted to be severe, the planting of these varieties should be reduced to minimize the adverse effects of T. turkestani on soybean yield and quality.

The phytoseiid mite Neoseiulus cucumeris (Oudemans) is recognized as one of the most effective predatory mites and is widely used in the commercial control of various greenhouse pests. In the present study, the influence of four different pollens, musk willow (Salix aegyptica L.), sunflower (Helianthus annuus L.), cherry (Prunus cerasus L.), and pear (Pyrus boissieriana L.) on the biological and reproductive performance of N. cucumeris was evaluated under controlled laboratory conditions (25 ± 2 °C, 60 ± 5% RH, and 16:8 h L: D photoperiod) using the island method. The findings demonstrated that the shortest and longest preadult developmental periods were recorded on sunflower (8.84 days) and cherry pollen (11.54 days), respectively. Male and female longevity was also significantly higher on sunflower pollen (49.54 and 37.17 days, respectively). Fecundity of females fed on sunflower, musk willow, pear, and cherry pollens averaged 35.42, 31.76, 22.70, and 21.06 eggs/female, respectively. The highest demographic parameters, including net reproductive rate (R₀ = 15.36), gross reproductive rate (GRR = 24.26), finite rate of increase (λ = 1.1411), intrinsic rate of increase (r = 0.1319), and mean generation time (T = 20.70 days), were obtained with sunflower pollen, whereas the lowest values were associated with cherry pollen. Overall, the results suggest that sunflower pollen is a superior dietary resource for N. cucumeris. Moreover, given that rearing this predator up to the 10th generation on sunflower pollen did not adversely affect its biological performance although predation rates declined in generations G0 and G20 this alternative food source can be recommended for the long-term mass rearing of N. cucumeris.

A laboratory study compared two synthetic acaricides, cyetpyrafen (SYP-9625) and abamectin, with two oils-a soybean-based vegetable oil and a mineral oil-against the citrus red mite (Panonychus citri) using a susceptible laboratory strain, a field population, and an F₁-selected population. SYP-9625 and abamectin caused rapid adult mortality and completely suppressed mite fecundity, whereas the vegetable oil required longer exposure to achieve complete mortality and had minimal effects on reproduction at sublethal concentrations. The mineral oil provided a rapid knockdown of adults. After one generation of selection, resistance ratios to SYP-9625 and abamectin increased sharply, while resistance to both oils rose only slightly; accordingly, abamectin and SYP-9625 exhibited the highest resistance risk, and the vegetable oil the lowest. All treatments had minimal adverse effects on F₁ developmental survival, indicating no substantial transgenerational fitness costs. These findings support the integration of vegetable and mineral oils into integrated pest management (IPM) programs for sustainable citrus mite control, offering effective population suppression with a lower risk of rapid resistance development.

Hyalomma dromedarii (H. dromedarii) is a major ectoparasite of camels in arid regions such as Egypt, where it causes significant economic losses and transmits several zoonotic pathogens. This study evaluated the acaricidal efficacy of a novel, locally prepared Astragalus polysaccharides nanoemulsified formulation (APS-NE) against various developmental stages of H. dromedarii infesting camels. APS-NE was prepared using ultrasonic emulsification and characterized by dynamic light scattering, transmission electron microscopy, and GC-MS, revealing uniform nanoparticle size (30-53 nm), good water solubility, and bioactive constituents including palmitic acid and quercetin derivatives. The formulation exhibited strong biological activity with very low toxicity and a wide safety margin in mice. In vitro bioassays showed a clear concentration-dependent acaricidal effect following short immersion periods: at 2% APS-NE, mortality reached 100% for eggs, larvae, nymphs, and unfed adults. Mortality rates at lower concentrations (0.5-1.5%) ranged from 63.6% to 94.6% in eggs, 33.6% to 84.3% in larvae, 53.3% to 93.6% in nymphs, and 31% to 87% in unfed adults, with larvae being the most susceptible stage. APS-NE also significantly impaired reproductive parameters in engorged females, including reductions in egg production index, egg mass, and hatchability compared to the reference drug. Strong positive correlations were observed between APS-NE concentration and tick mortality, with negative correlations for reproductive metrics. These results highlight APS-NE as a safe, eco-friendly alternative to conventional acaricides for effective H. dromedarii control, supporting integrated tick management strategies.