Experimental and Applied Acarology最新文献

Ecological interactions among organisms play a crucial role in shaping the dynamics of agricultural ecosystems, contributing to equilibrium and functional biodiversity within agroecosystems. In this study, we hypothesized that the presence of T. urticae detrimentally affect the population growth of T. ludeni on the host plant. The experimental design involved analyzing a multifaceted ecological dynamic related to four biological attributes: oviposition, olfactory cues, web effects, and mite interaction. Data were analyzed using Generalized Linear Mixed Model (GLMM). Our results showed that T. urticae does not significantly influence the oviposition rate of T. ludeni. However, T. ludeni prefers its conspecifics over heterospecifics, avoiding the presence of the web produced by T. urticae. Additionally, our findings indicate that T. ludeni has a low population growth in plants with T. urticae, whereas T. urticae is favored by the presence of T. ludeni. Since both spider mite species may damage crop production by piercing plant cells with their mouthparts, our results suggest that their interaction may have broader implications for herbivorous mite ecology in agroecosystems, particularly because the population of T. urticae seems to be favored by interacting with T. ludeni. Therefore, these findings are significant for pest control strategies, as the presence of both spider mite species in the same agricultural ecosystem may result in one outnumbering the other instead of self-regulating each other.

Equine piroplasmosis (EP) is a worldwide infection of Equides caused mainly by Theileria equi and Babesia caballi. Recently, these agents have been found in horses in the Republic of Altai. To identify probable vectors for EP agents in Western Siberia, 443 adult questing Dermacentor spp. (199 D. silvarum, 236 D. nuttalli, and 8 D. marginatus) were collected from vegetation in four districts of the Republic of Altai and examined for the presence of Piroplasmida DNA. Three Piroplasmida species were identified. Babesia caballi was found in ten (2.3%) Dermacentor spp., including eight D. silvarum and two D. nuttalli, indicating that these species are probable vectors of B. caballi in Siberia. The determined 18 S rRNA gene sequences of B. caballi from ticks were identical to those previously found in equine blood from the same region, which demonstrated their involvement in common transmission cycles. Another agent of EP, T. equi, was found in only one D. silvarum, indicating that in studied region Dermacentor spp. hardly can efficiently transmit T. equi transstadially. In addition to EP pathogents, the agent of bovine mild piroplasmosis, Babesia occultans, was identified in one D. marginatus; this is the first detection of this agent in Russia.

Terrestrial parasitengone mites (Prostigmata: Parasitengona) are known for their complex life cycles, with active forms confined to larvae, deutonymphs, and adults, and quiescent proto- and tritonymphal stages. Knowledge of the host range of parasitic larvae of most species is still limited, but it is likely that host choice and suitability may influence intraspecific variation of subsequent developmental instars. In this study we assessed the variation of morphometric traits in unfed deutonymphs of Allothrombium fuliginosum which developed from larvae that had parasitized four different aphid hosts: Acyrthosiphon pisum, Aphis sambuci, Macrosiphum rosae and Hyadaphis sp. Analysis of 48 morphometric traits in 80 deutonymphs revealed significant differences between host groups in 19 traits, with M. rosae contributing the most to observed variability. Principal component analysis showed some distinct clustering of deutonymphs according to the host species parasitized by larvae. The smaller, with respect to basic body measurements, deutonymphs developed from larvae that parasitized M. rosae, despite the overall larger body size of this host. Thus, factors other than host size influence the morphology of mites. The findings enhance our understanding of host-parasite interactions and highlight the need for further insight into sources of intraspecific variability within terrestrial Parasitengona.

Ticks transmit various diseases to humans and animals, posing a significant global threat to public health. The primary method currently employed to control tick infestations is the use of chemical acaricides. However, improper use leads to environmental contamination, residue in meat and milk, and the development of acaricide-resistant ticks. Therefore, alternative tick control methods that are safe for humans, animals, and the environment and that do not induce resistance are urgently needed. Diatomaceous earth (DE), a naturally occurring physical insecticide, has been proven to effectively kill various arthropods without producing resistance or toxic side effects. In the present study, the acaricidal effects of DE on larval, nymphal, and adult stages of Haemaphysalis longicornis ticks were evaluated using sprinkling and immersion methods. In larvae, mortality was first observed 20 min after sprinkling, with a 100% mortality rate by 200 min. Immersion treatment of nymphs with DE resulted in initial mortality observed after 120 min, and the mortality rate reached 100% after 12 h. The initial mortality rate for adult male ticks was 5% after 8 h of treatment, and 5% for adult female ticks after 6 h treatment. By 24 h, the mortality rates for both adult male and female ticks had reached 100%. These findings demonstrate that DE has acaricidal effects on the larval, nymphal, and adult stages of H. longicornis under laboratory conditions. Our study provides a foundation for future field trials to explore DE as a safe and effective alternative to chemical acaricides in tick control methods.

Phytotelmata provide favorable habitats for invertebrates, such as insects and mites. However, previous acarofauna studies on phytotelmata have primarily focused on tree holes, pitcher plants, and bromeliads, leaving other types, such as the leaf axils of aroids, underexplored. Therefore, the present study aimed to determine the composition of the acarofauna in the leaf axils of two Araceae species, Xanthosoma daguense Engl. and Xanthosoma sagittifolium (L.) Schott, as well as establish the aquatic and subaquatic aroid-mite network. For this, we collected mites from the phytotelmata of both species at two sites in the Colombian Central Mountain range. We found 16 morphospecies of mites belonging to the Gamasina, Uropodina, Sejida, Astigmatina, and other Oribatida groups associated with the phytotelmata of aroids. The most common genera identified were Histiostoma sp. and Hormosianoetus sp. (Histiostomatidae, Astigmatina). We reported for the first time the occurrence of Blattisocius dentriticus (Blattisociidae), Cheiroseius mesae (Blattisociidae), Galumna sp., Lucoppia sp., Malaconothrus sp., Oribotritia sp., and Uropodella sp. in phytotelmata, as well as B. dentriticus, Asca sp., Hormosianoetus sp., Lucoppia sp., Malaconothrus sp., and Phthicarus sp. in Colombia. The network exhibited high specialization and modularity; we identified three aroid-mite groups related to the Araceae species by sites. These results suggested that variations in the environmental conditions in the leaf axil and site scales affect the mite community. Thus, these results extend the understanding of phytotelma as habitats for mites, thereby contributing to the knowledge of their role in conserving these taxonomic groups.

Leaf structures influence the community structure of small arthropods on the leaf surface. For example, several taxa of mites, primarily fungivorous and carnivorous, use domatia as refuges, leading to direct and indirect interactions among predators, prey and plants. However, the impact of insect-induced leaf deformities (galls and leaf shelters) on the mite community remains poorly understood. In this study, we focused on a population of Eotetranychus asiaticus (Acari: Tetranychidae) colonising the galls formed by psyllid larvae (Trioza cinnamomi, Hemiptera: Triozidae) on the leaves of Cinnamomum yabunikkei (Lauraceae). We tested the hypothesis that inhabiting galls benefits E. asiaticus by reducing egg predation. In the field, almost all E. asiaticus individuals were found inside galls (96.7%). This spider mite inhabited 3.4% of the observed galls and reproduced within them, whereas leaves without galls hosted few mites. Predatory mites and Feltiella larvae used galls near those occupied by spider mites, indicating high predation pressure on the leaf surface. Laboratory experiments revealed that the proportion of eggs predated by Neoseiulus womersleyi (Phytoseiidae) females was lower on leaves with galls than on leaves without, suggesting that gall use provides an antipredatory advantage. In conclusion, psyllids indirectly assist the coexistence of E. asiaticus with predators by creating defensive microhabitats.

In practical agricultural systems, multiple pest species often coexist, posing a significant challenge for pest control. Polyphagous predatory mites, especially Phytoseiidae, play a dominant role in biological control, owing to their ability to suppress multiple pests. Currently, there is a lack of information on the effect of temperature shifts on prey preference of polyphagous predatory mites. In this study, we examined the prey consumption and prey preference of Amblyseius andersoni (Chant) on two important agricultural pests, the two-spotted spider mite (Tetranychus urticae Koch) and the western flower thrips (Frankliniella occidentalis Pergande), at five different temperatures (15, 20, 25, 30, and 35 °C). The preference for T. urticae larvae weakened with increasing temperature; the maximum at 15 °C (Manly's preference index β = 0.8952) and the minimum at 30 °C (β = 0.6584). The prey consumption of T. urticae was the lowest at 35 °C (5.93 per day) and the highest at 25 °C (9.23 per day); the highest and the lowest prey consumption of F. occidentalis were observed at 30 °C (1.73 per day) and 15 °C (0.33 per day), respectively. Moreover, we found that the prey preference of A. andersoni on the two prey may be related to the antipredator behavior of F. occidentalis, but not to the relative ratios of prey. Our study highlights the importance of temperature conditions when using generalist natural enemies to control multiple pests.

Thermal adaptation plays a crucial role in shaping the development, reproduction and population dynamics of ectothermic organisms. In this study, we compared thermal life history traits among three closely related social spider mites: Stigmaeopsis sabelisi, S. miscanthi high-aggression (HG) form, and their common ancestral group, S. miscanthi mild-aggression (ML) form. We investigated the minimum temperature thresholds for development by measuring the days required for egg hatching under five constant temperature conditions (15 °C, 20 °C, 25 °C, 30 °C, 32 °C) and estimating the thresholds using linear and nonlinear regression models. Additionally, we assessed their reproductive diapause attributes. Our results revealed that the minimum development thresholds were slightly lower in S. sabelisi from colder regions compared to S. miscanthi HG form and S. miscanthi ML form distributed in warmer and subtropical regions. Notably, high-temperature stress negatively affected development only in S. sabelisi, suggesting local adaptation. Reproductive diapause attributes also varied: reproductive diapause was induced under short-day conditions in S. sabelisi, whereas the other two species lacked such diapause. Moreover, phenotypic variation in the number of days required for egg hatching was highest in S. miscanthi ML form, suggesting retained ancestral variability that may have facilitated subsequent divergence. These findings support the hypothesis that populations from colder environments exhibit lower thermal thresholds and more intense diapause than those from warmer environments, and also provide insights into the mechanisms driving local adaptation and speciation in the social spider mites.

Haemaphysalis flava Neumann, 1897 is recognized as a vector for Dabie bandavirus (severe fever with thrombocytopenia syndrome virus, SFTSV), which is the etiological agent of severe fever with thrombocytopenia syndrome (SFTS). The tick vector has proliferated and expanded globally in recent years, likely due to the migration of birds. In this study, we selected the mitochondrial 16S rRNA as the genetic marker to analyze the population genetics of H. flava collected from Nantong, China and other regions separated by geographical barriers, all of which are located along the East Asia-Australasian Flyway (EAAF). Our research revealed significant gene flow among tick populations, which are characterized by low genetic diversity, minimal phylogeographic structure, and the interconnected haplotype network. We identified a total of 38 haplotypes, including 5 shared haplotypes. The high overall average of haplotype diversity, the shared haplotypes with large sample size covering many regions, and the abundant exclusive haplotypes in our study supported that H. flava had the ability to adapt to different environments among the large geographical range along the EAAF. The study did not support the recent expansion of the H. flava population in Nantong. Continuous surveillance of H. flava along the EAAF is essential.

Phytonemus pallidus fragariae Zimmerman (Trombidiformes: Tarsonemidae) is an important pest in strawberry cultivation worldwide, causing considerable economic losses with yield reductions ranging from 22 to 100%. This study investigated the population parameters of P. p. fragariae on three commercially important strawberry cultivars: Albion, Monterey, and San Andreas, using an age-stage, two-sex life table approach. All experimental procedures were conducted under the controlled conditions of 25 ± 2 °C, 65 ± 5% RH, and a 16:8 h (light: dark) photoperiod. The results showed that some developmental times and life table parameters of P. p. fragariae differed among the cultivars. Total pre-adult duration was longest on Albion (8.23 days), followed by Monterey (7.65 days) and San Andreas (7.10 days). Fecundity was highest on Albion (11.85 eggs/female), while no differences were observed in net reproductive rate, intrinsic rate of increase, and finite rate of increase among cultivars. However, the mean generation time was longest on Albion (13.85 days) and shortest on San Andreas (12.10 days). The findings indicate that the Albion cultivar is more suitable for development and reproduction. P. p. fragariae than the Monterey and San Andreas cultivars. This study provides initial insights into the life table parameters of P. p. fragariae on specific strawberry cultivars, enhancing our understanding of pest-host interactions. The data generated helps develop more effective integrated pest management (IPM) strategies targeting this pest in strawberry production systems.