Experimental and Applied Acarology最新文献

The spider mite species Tetranychus gloveri Banks has emerged as a major pest of adenium in Kerala, South India. The sole reliance on synthetic acaricides for mite management has led to the development of resistance in T. gloveri populations, highlighting the need for alternative management strategies. The phytoseiid mite, Neoseiulus longispinosus Evans is a widely distributed predator of spider mites, adaptable to warm temperatures. The present study evaluates the efficacy of N. longispinosus against T. gloveri on adenium in the laboratory through functional and numerical response studies and in the polyhouse by a pot culture experiment. The functional response of N. longispinosus was studied on different life stages of T. gloveri, while the numerical response was studied on adult T. gloveri at different densities in a modified Munger cell. The pot culture experiment was conducted in completely randomised design (CRD) by releasing predators twice at 10-day intervals, at different predator-prey ratios of 1:25, 1:50, 1:75, 1:100, and 1:125 on adenium plants infested with T. gloveri. The functional response of N. longispinosus to all life stages of T. gloveri provided evidence for a Type-II response. The predator consumed all stages of T. gloveri, exhibiting the highest preference for the eggs, followed by the larvae, protonymphs, deutonymphs, and adult stages. The numerical response studies carried out at different densities revealed that the oviposition rate of the predator increased with an increase in prey density and prey consumption, recording a maximum of 3.05 eggs/day at the prey density of 12. In the polyhouse, the narrow predator-prey ratios of 1:25 and 1:50 significantly reduced the mite population to the tune of 94.50 and 61.95 per cent, respectively, after two releases of the predator, while the ratio 1:75 brought about 28.98 per cent reduction. However, wider predator-prey ratios were not effective.

This study evaluated the acaricidal activity of the natural terpene linalool against Rhipicephalus microplus larvae. Four tick populations from different cattle farms with a history of acaricide resistance were selected. The Larval Packet Test (LPT) was used to determine the lethal concentrations (LC50 and LC90) of linalool, cypermethrin, and the combination of LC50 linalool and cypermethrin. Linalool was tested at concentrations ranging from 0.0975 to 50%, while cypermethrin was tested between 0.01% and 3%. The results demonstrated that linalool alone had LC50 values varying across the populations, ranging from 0.5 to 4.33%, and LC90 values ranging from 2.57 to 7.61%. When linalool was combined with cypermethrin, the required concentrations of cypermethrin to achieve LC50 and LC90 were significantly reduced (p ≤ 0.05). This reduction in cypermethrin dosage was observed across all tested populations, indicating that linalool can enhance the acaricidal efficacy of cypermethrin. Integrating linalool with cypermethrin could therefore be valuable for tick management strategies, particularly in reducing reliance on high doses of these acaricides.

Amblyseius orientalis Ehara (Mesostigmata: Phytoseiidae) has garnered significant attention as an effective predatory mite for controlling spider mites in fruit production in China. However, despite its considerable potential for pest management, A. orientalis may face food shortages during transportation and field application. Currently, there is a lack of information on the effects of starvation on the development, survival, and reproductive capacity of A. orientalis. In this study, we evaluated the impact of starvation on the development, survival and reproduction of A. orientalis. We found that female adults exhibited greater tolerance to starvation than larvae and protonymphs. Approximately 50% of the female adults survived after eight days of starvation. Interestingly, starvation during the early developmental stages extended lifespan, nearly doubling male longevity from 20.56 to 38.00 days, and increasing female longevity from 44.68 to 70.31 days. However, starvation in female adults reduced egg production from 18.46 to 5.33 eggs over a period of ten days, while male reproductive abilities increased from 18.46 to 19.41 eggs. Additionally, the sex ratio of the offspring was not influenced by paternal starvation, but maternal starvation resulted in a male-biased offspring ratio. In conclusion, our study demonstrates that A. orientalis can tolerate starvation at various life stages, enabling it to withstand food shortages during both transportation and application.

This study reports on the first documented case of Amblyomma rotundatum ticks, a species typically found in the Americas, parasitising an imported toad in Poland. A total of 12 ticks were collected from a single Rhinella marina toad. These ticks were identified as female specimens of A. rotundatum using an examination of morphological characteristics and a molecular analysis. Polymerase chain reaction testing revealed that 75.0% (9/12) of these females were positive for Rickettsia spp. Sequencing of positive samples confirmed the presence of R. bellii. However, no DNA evidence of Borrelia spp. and Anaplasma spp. was detected in the tested ticks. Nevertheless, given the limited number of tick specimens collected from a single host, further research is required to elucidate the pathogen profile of a tick species. This finding represents the second European report of A. rotundatum associated with exported animals, underscoring the importance of vigilance in monitoring the potential spread of ticks and tick-borne pathogens through the global wildlife trade.

Ticks of the Genus Rhipicephalus occur worldwide. Especially members of Rh. sanguineus s.l. are primarily associated with dogs. As unwanted souvenirs, they are introduced by dogs into non-endemic areas such as Germany, where they can establish and reproduce indoors. A citizen-science study was conducted between 2019 and 2024, asking interested citizens to report tick infestations and send in travel related tick findings which were associated with dogs and were focused on Rhipicephalus species. Tick species were identified using the 16S rRNA gene and tested for pathogens associated with the genus Rhipicephalus. In addition, each tick introduction was considered as a case and categorized and analyzed individually. During the study period, 44 cases were reported. In 17 cases tick specimens were identified as Rh. sanguineus s.s., Rh. rutilus, Rh. linnaei, Rh. turanicus, and Rh. haemaphysaloides which were imported from other European countries and Sri Lanka. Neither Hepatozoon canis, Ehrlichia canis nor Babesia vogeli were detected in any of the 780 received specimens. In contrast, Rickettsia spp. was detected in 50 specimens from six independent cases, with Rickettsia massiliae being identified in 44 specimens. The import of dogs from abroad as well as travel with dogs lacking appropriate tick prophylaxis are responsible for more than 80% of cases. This Project highlights the risk of introductions of non-endemic tick species. Also, professionals such as veterinarians, animal welfare organizations and pest controllers need to be made aware of the possible introduction of Rhipicephalus spp. to ensure early recognition and rapid elimination of the ticks.

Though the entomopathogenic fungus Beauveria bassiana has shown to be efficacious for managing Dermanyssus gallinae infestations, its delivery as liquid formulation poses concerns related to environmental stability and efficacy. To overcome such concerns, here we proposed a hydrogel matrix based on hydroxyethyl-cellulose (HEC) for delivering B. bassiana to control D. gallinae. Nymph and adult mites were exposed to a hydrogel matrix or filter papers containing B. bassiana (10⁷ conidia/mL), with and without a pre-incubation period of 4 days at 25 °C (treated groups). As control groups, mites were exposed to hydrogel matrix or filter papers with sterile distilled water. Results showed higher mortality of all stages of D. gallinae in treated groups compared to respective control groups. The LT₅₀ and LT₉₀ estimated on D. gallinae were lower in treated groups (LT₅₀ ≤ 9.5 days for adults; and LT₅₀ ≤ 10.7 days for nymphs; LT₉₀ ≤ 14.9 for adults; LT₉₀ ≤ 17.9 days for nymphs) than in control groups (LT_{5 0} ≥14.9 days for adults, LT₅₀ > 19 days for nymphs; LT₉₀ > 20 days for adults and nymphs). Pre-incubation significantly reduced LT₅₀ and LT₉₀ with respect to other treated groups. Overall, our study outlined that the conidial suspension of B. bassiana in hydrogel is efficacious against both nymphs and adults of D. gallinae. The pre-incubation of B. bassiana in the HEC enhanced its efficacy. Thus, delivering B. bassiana through HEC-based hydrogel matrix may represent an effective and sustainable solution for managing D. gallinae infestations in the poultry industry.

Hard ticks are essential biological vectors of pathogens with impacts on humans and animals. This study tried to identify the dominant species of hard ticks, assess their biodiversity, and compare the infestation rates in mountainous to semi-mountainous regions in Fars province, southwestern Iran, during 2021-2022. In total, 4104 domestic animals, such as sheep, goats, cows, camels, and dogs, were examined; 3169 ticks belonging to three genera, Hyalomma, Rhipicephalus, and Dermacentor, were collected. Hyalomma anatolicum was the most dominant species (34.39%), and Dermacentor marginatus was the least frequently found species. Biodiversity analysis by Simpson, Shannon-Wiener, Evenness, and Margalef indices. Generally, species richness, Evenness, and Shanon - Wiener indices were higher in mountainous than semi mountainous area and also results showed a higher diversity and richness in sheep from mountainous regions, especially in Firouzabad. Dogs and camels in Larestan had the lowest diversity and richness. Also, cattle in Marvdasht presented the highest species uniformity. The results reveal that biodiversity and the infestation rate are higher in sheep, thereby increasing the risk of tick-borne diseases. Thus, closer monitoring of livestock, education of farmers, and effective management of ticks are required to reduce the impact of tick infestations and associated diseases within this region.

Species from various animal taxa have been found to use pheromonal communication underwater. Although the use of pheromones in water mites has been previously suggested, experimental evidence for it remains sparse. We examined the behavioral responses of male and female Arrenurus globator to water in which conspecifics of the same and the opposite sex had been kept, in order to test the hypothesis that chemical communication occurs between sexes. Results suggest a putative female-produced sex pheromone that stimulates at least the initial steps of mating behavior in males. Males exhibited arrestant behavior, leg fanning and readiness posture more in female-conditioned water than in male-conditioned or control water. In contrast, females showed no response to either male-conditioned water or female-conditioned water.

Ticks are a medically important group of arthropods, and their control has become a major challenge due to their widespread resistance to synthetic acaricides. Defatted seed meals of plants in the mustard family, commonly generated as byproducts of vegetable oil and biofuel production are known to possess pesticidal properties but their potential to control ticks remain poorly understood. We evaluated the bio-fumigation activity of defatted seed meals of three mustard family species, Brassica juncea (L) Czern. (PG), Lepidium sativum L. (Ls) and Thlaspi arvense L. (DFP), against three medically important hard tick species: Ambylomma americanum (L.) [Aa], Dermacentor variabilis (Say) [Dv] and Ixodes scapularis (Say) [Is]. Volatiles produced by defatted seed meals of the three plant species had strong bio-fumigation activity against ticks, but their effects varied among the three tick species. Toxicity of DFP seed meals was significantly different among the three tick species (no overlap of the 95% CI) with LD₅₀ values of 0.056 g for Aa nymphs, 0.031 g for Dv nymphs, and 0.037 g for Is nymphs. Defatted Ls seed meals were more toxic to Dv (LD₅₀ = 0.022 g) and Is (LD₅₀ = 0.018 g) nymphs compared to Aa nymphs (LD₅₀ = 0.035 g) while defatted PG seed meals were more toxic to Is nymphs (LD₅₀ = 0.009 g) compared to Aa (LD₅₀ = 0.048 g) and Dv (LD₅₀ = 0.032 g) nymphs. This study is the first report to document that defatted Brassicaceae seed meals are a promising plant-based biofumigant for tick control that can be developed as a cheap, practical, and ecofriendly acaricide.

The factors influencing the distribution and abundance of ectoparasites in vertebrates have been thoroughly examined in rodents, particularly concerning ticks and fleas. However, there is a paucity of knowledge regarding mites. The aim of this study was to determine if host or landscape traits are responsible for the abundance of dermanyssoid and trombiculoid mites. Rodent captures were carried out in the northwest region of Mexico between 2018 and 2022 in order to collect mites of the superfamilies Dermanyssoidea and Trombiculoidea. We generated generalized linear models to determine if rodent characteristics or the Index of Relative Anthropization (IRA) contribute to the relative abundance of Dermanyssoidea and Trombiculoidea. The best generalized linear model for Dermanyssoidea suggests that mite abundance is influenced by the IRA and the terrestrial rodent abundance. There is a relationship between the abundance of terrestrial rodents and dermanyssoid mites. Data show that as anthropization increases, Dermanyssoidea abundance decreases. The model shows rodent abundance, and the IRA are key factors in Trombiculoidea abundance. Our findings indicate that trombiculoid mites increase alongside rodents but decline as the IRA increases. This is the first study to use an index to investigate the impact of relative anthropization on Dermanyssoidea and Trombiculoidea in Mexico.