Search Results (306)

The living roots of woody plants in forests play a crucial role in sustaining the soil temperature equilibrium. However, there is limited research investigating the effects of soil temperature balance disruption, influenced by living roots, on soil microarthropods, especially in the context of global climate change. To address this knowledge gap, we conducted a three-year in situ simulation experiment involving either experimental warming or root trenching treatments to mimic environmental changes and their impacts on soil microarthropod communities in a temperate forest ecosystem in Northeast China. Statistical analysis focused on assessing the abundance and family richness of Collembola and Acari. Warming increased soil temperature, while root trenching had contrasting effects. In the absence of root trenching, warming positively influenced Collembola but negatively affected Acari. Conversely, when combined with root trenching, warming had a diminished impact on both Collembola and Acari. Our findings demonstrate that the interactive effects of warming on soil microarthropod communities vary depending on the presence or absence of root trenching. Specifically, within the context of root trenching treatment compared to no-root trenching treatment, warming exhibited a comparatively attenuated influence on soil microarthropod communities. Overall, living roots play a pivotal role in mediating soil temperature conditions, which significantly impact soil microarthropod communities in the context of global climate change. Full article

Forest fires are commonly regarded as negative for ecosystems; however, they also represent a major ecological force shaping the biodiversity of invertebrates and many other organisms. The aim of this study was to better understand how multiple groups of invertebrates respond to wildfire across different forest types in Central Europe. The research was conducted following a large forest fire (ca. 1200 ha) that occurred in 2022. Data were collected over two years (2023 and 2024), from April to September. The research was conducted in coniferous forests and included six pairwise study types: burnt and unburnt dead spruce (bark beetle affected), burnt and unburnt clear-cuts, and burnt and unburnt healthy stands. In total, 96 traps were deployed each year. Across both years, 220,348 invertebrates were recorded (1.Y: 128,323; 2.Y: 92,025), representing 24 taxonomic groups. A general negative trend in abundance following forest fire was observed in the groups Acari, Auchenorhyncha, Blattodea, Dermaptera, Formicidae, Chilopoda, Isopoda, Opiliones, and Pseudoscorionida. Groups showing a neutral response included Araneae, Coleoptera, Collembola, Diplopoda, Heteroptera, Psocoptera, Raphidioptera, Thysanoptera, and Trichoptera. Positive responses, indicated by an increase in abundance, were recorded in Hymenoptera, Orthoptera, Lepidoptera, and Diptera. However, considerable differences among management types (clear-cut, dead spruce, and healthy) were evident, as their distinct characteristics largely influenced invertebrate abundance in both unburnt and burnt variants of the types across all groups studied. Forest fire primarily creates favorable conditions for heliophilous, open-landscape, and floricolous invertebrate groups, while less mobile epigeic groups are strongly negatively affected. In the second year post-fire, the total invertebrate abundance in burnt sites decreased to 59% of the first year’s levels. Conclusion: Forest fire generates a highly heterogeneous landscape from a regional perspective, creating unique ecological niches that persist more than two years after fire. For many invertebrates, successional return toward pre-fire conditions is delayed or incomplete. Full article

The presence of nest boxes not only increases the reproductive success of many passerine birds in transformed forest habitats, but they also constitute important artificial microhabitats for many groups of invertebrates. One of such groups which have been often found in this microhabitat is saprophagous mites from the suborder Uropodina (Acari: Mesostigmata). The current study was conducted in October 2023 and 2024 in Bory Tucholskie National Park (BTNP) (northern Poland), where material from 137 tit (Paridae) and nuthatch (Sitta europaea) nest boxes was collected. The aim of this study was to analyse the stability of the communities of Uropodina in nest boxes in the park in two seasons and to determine whether the mite community structure within these nest boxes is similar in each year. The second aim was to analyse the abundance of Uropodina in relation to the composition of the nest box bedding material. This study revealed that the community in the scrutinised nest boxes was formed in both seasons by two species of nidicolous Uropodina species, i.e., Leiodinychus orbicularis (C.L. Koch, 1839) and Chiropturopoda nidiphila (Wiśniewski and Hirschmann, 1993), and that the species composition and the community structure were also very similar in both years. This study revealed that Ch. nidiphila dominated in the nest boxes with moss and grass, whereas L. orbicularis was most abundant in the boxes where the bedding was a mixture of mammalian hair and grass. However, no statistically significant differences in the abundance of these two mite species in both cases were revealed. Full article

Studying the nutritional ecology of Neoseiulus cucumeris (Oudemans) at different temperatures is a fundamental tool for improving mass production for use in biological control of pest mites. The current research studied the impact of both food types and temperatures on the life history and demographic parameters of the predator mite N. cucumeris. Mite cultures in the laboratory were developed using Tetranychus urticae Koch, and N. cucumeris was collected from field plants. The developmental stages of N. cucumeris fed on date palm pollen and the immature stages of T. urticae were investigated in a laboratory setting at different temperatures. Our research revealed that N. cucumeris readily accepted both food types at all the tested temperatures. The developmental stages and adult longevity of N. cucumeris, both female and male, decreased dramatically when the temperature increased from 18 °C to 34 °C. The net reproductive rate (R₀) reached its greatest values of 22.52 and 9.72 offspring/individual at 26 °C, and the intrinsic rate of increase (r_m) reached its maximum values of 0.17 and 0.13 day⁻¹ at 34 °C and minimum of 0.12 and 0.10 day⁻¹ at 18 °C, when fed on date palm pollen and immature stages of T. urticae, respectively. Conversely, the average generation time (T) showed a notable reduction from 22.48 to 16.48 and 20.88 to 16.76 days, accompanied by an upsurge in temperature from 18 °C to 34 °C, when fed on date palm pollen and immature stages of T. urticae, respectively. The finite rate of growth (λ) exhibited distinct variations, reaching its highest value at 34 °C, 26 °C, and 18 °C when fed on date palm pollen and immature stages of T. urticae, respectively. From these results, we can conclude that N. cucumeris was successfully fed date palm pollen as an alternate source of nourishment. In addition, the immature stages of T. urticae are suitable as food sources for N. cucumeris because they shorten the mean generation time. Therefore, the success of mass-rearing the predator mite N. cucumeris on a different, less expensive diet, such as date palm pollen, and determining the most suitable temperature for it has increased its spread as a biocontrol agent. Full article

The Tetranychus urticae Koch (Acari: Tetranychidae) is one of the primary pests affecting buckwheat, and its management has become increasingly critical. Entomopathogenic fungi offer a promising way to solve this problem by providing both pest control and disease resistance, as well as promoting plant growth through endophytic colonization. This study investigated the effects of applying Isaria cateniannulata (Liang) Samson & Hywel-Jones and Beauveria bassiana (Bals.-Criv.) Vuill. on different buckwheat varieties, and analyzed the physiological indices of buckwheat, the population of T. urticae and Euseius nicholsi (Ehara & Lee). Results showed that the optimum concentration for fungal colonization on buckwheat was 1 × 10⁷ spores/mL. The combined application of I. cateniannulata and B. bassiana significantly enhanced buckwheat growth, with root length, plant height, main stem diameter, fresh weight, and dry weight reaching 63.3 mm, 24.1 cm, 2.1 mm, 2.0 g, and 0.1 g, respectively. The highest escape rate of T. urticae was 76.33%. Furthermore, the combined application of mixed fungal suspension and E. nicholsi had the best control effect on T. urticae, with pest suppression exceeding 97.83% and an oviposition as low as 0.25 eggs per female. This study is the first to demonstrate that the joint application of I. cateniannulata and B. bassiana can promote buckwheat growth and, when combined with predatory mites, effectively control T. urticae. These findings provide a theoretical basis for the development of integrated biocontrol strategies combining entomopathogenic fungi and predatory mites. Full article

Ticks are arthropods responsible for transmitting microorganisms important to wild, domestic, and human animals. In ecosystems where they are distributed, interactions between hosts are a constant risk. This study analyzed voluntary case reports of tick infestations in humans and tick collections from wild and domestic animals in six different locations in the flooded savanna region of the Colombian Orinoquia. Classical and molecular taxonomy were used to identify tick species. Individuals infested with ticks were monitored for clinical manifestations related to tick bites. A total of 22 ticks were found infesting five men and one woman, aged between 9 and 60 years. Both classical and molecular taxonomy confirmed that 100% of the ticks infesting humans and animals were Amblyomma mixtum. Two of the six individuals reported primary and secondary skin reactions during and after the tick bite, including mild-to-severe inflammatory reactions, pruritus, and erythematous papules that persisted up to 72 h. This study provides, for the first time, compiled information on clinical skin manifestations caused by A. mixtum in humans in the flooded savanna region and in Colombia as a whole. These findings serve as a theoretical basis for developing surveillance programs targeting infestations caused by this arthropod. Full article

The two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is a major pest of horticultural, ornamental, fruit, and strawberry crops worldwide. Currently, various management tools have been explored for this pest, with nanoparticles being one of them, which stand out for their characteristics and multiple effects. This study evaluated the effects of green-synthesized gold nanoparticles (AuNPs) on the mortality and repellency of T. urticae and its natural predator Phytoseiulus persimilis under laboratory conditions, as well as their efficacy in greenhouse tomatoes against T. urticae. In the laboratory, a biological window for AuNPs (50–100 mg L⁻¹) on the pest and predator was established using a residual film method and a free-choice assay. In the greenhouse, four concentrations (300, 500, 750, and 1000 mg L⁻¹) were evaluated via foliar application at 10-day intervals. The results showed susceptibility to AuNPs in all stages of T. urticae and the adult P. persimilis. The death times from AuNPs were similar in both species. Furthermore, the AuNPs were selective for the pest rather than the natural enemy. In greenhouses, AuNPs affected T. urticae populations in tomato plants, and significant differences were observed on some continuous and final agronomic variables (associated with fruits). This study showed that T. urticae and P. persimilis were susceptible to green-synthesized AuNPs. AuNPs can be a management tool, although studies on other non-target species and estimating agronomic effects on other crops are recommended. Full article

Ixodiphagus hookeri (Howard, 1907) (Hymenoptera: Encyrtidae), a hyperparasitic wasp that parasitizes hard ticks, has been documented in various parts of Europe; however, data on its presence in southeastern regions has been lacking. This study provides the first molecular evidence of I. hookeri in ticks from the coastal areas of the Balkan Peninsula, specifically Croatia and Bulgaria. A total of 1043 questing ticks were collected between 2011 and 2013 across 15 locations. Molecular screening revealed I. hookeri DNA in Ixodes ricinus (Linnaeus, 1758) (Acari: Ixodidae) nymphs from inland Croatia (overall prevalence: 18.72%) and in Haemaphysalis concinna (Koch, 1844) (Acari: Ixodidae) nymphs and larvae from coastal Bulgaria (prevalence: 17.2%). All I. hookeri-positive samples were co-infected with Wolbachia spp. (Rickettsiales: Anaplasmataceae). This detection marks the southernmost record of I. hookeri in Central Europe, expanding its known range to the Balkan Peninsula and supporting its relevance as a potential natural enemy in integrated tick management strategies. Full article

The red spider mite, Tetranychus macfarlanei, is a significant pest of various crops, and silicon (Si), a beneficial micronutrient, serves as a physical defense against herbivores when accumulated in plant tissues. This study examined the effects of silicon on the biology of T. macfarlanei on Lablab purpureus plants treated with 0 ppm (control), 28, and 56 ppm silicon concentrations. The results showed that silicon treatments notably affected mite development. At the highest concentration of 56 ppm Si, females exhibited the longest immature period, shortest lifespan, and shortest oviposition period. Egg production per female was highest at the 0 ppm Si level (94.62) and lowest at the 56 ppm Si concentration (42.29). Life table parameters, including the intrinsic rate of increase (r), net reproductive rate (R₀), finite rate of increase (λ), and gross reproductive rate (GRR), declined progressively with increasing silicon concentrations. Compared to the control (0 ppm Si), the highest silicon level resulted in reductions of approximately 24% in r, 55% in R₀, 4% in λ, and 27% in GRR, indicating a substantial negative impact of silicon on the reproductive potential of T. macfarlanei. These findings suggest that higher silicon levels effectively suppress T. macfarlanei populations and may be useful in integrated mite management strategies. Full article

The nine-banded armadillo, Dasypus novemcinctus, is one of only two species of armadillo found in Mexico. Among the ectoparasites reported on this mammal are ticks of the genus Amblyomma. Between December 2022 and April 2024, 52 ticks of different developmental stages (females, males, and nymphs) were collected from five D. novemcinctus. All ticks were morphologically identified as A. auricularium. This study reports for the first time the presence of this tick species in the Municipality of Santiago Llano Grande, Oaxaca. Full article

Temperature is a critical factor affecting the development and population dynamics of many organisms. An organism’s ability to withstand extreme temperature events, such as heat waves, will become increasingly important as the severity, duration, and frequency of these events continue to rise worldwide due to global warming. Knowledge on the effects of heat stress on both pests and their natural enemies will thus be crucial for keeping biological control and pest control programs effective in future. This research aimed to study the effect of short-term heat stress on the predatory mite Phytoseiulus persimilis, which is one of the important natural enemies utilized as a biocontrol agent against spider mites such as Tetranychus urticae. The experiments assessed the immature developmental time of P. persimilis after a four-hour incubation of eggs at high temperatures, namely 36, 38, 40, and 42 °C, as well as 85 ± 5% RH and a 16:8 h photoperiod (L:D). After adult females emerged, they were exposed to the same conditions again and the population parameters were monitored. The results demonstrated that the immature development time decreased as temperature increased, with the shortest development duration of 5.30 days seen in eggs exposed to 40 °C, while the eggs exposed to 42 °C did not hatch. Female and male adult longevity decreased significantly as the temperature increased. Fecundity, the adult pre-ovipositional period, and the total pre-ovipositional period were lowest following the 40 °C treatment. The population parameters of P. persimilis, including r and λ, reached their highest values in mites treated at 36 °C, and were significantly higher than in the control group. Addressing these challenges through targeted research and adaptive management is essential to sustaining the efficiency of P. persimilis in biocontrol programs, particularly in the context of global climate change. Full article

Tetranychus urticae (Acari: Tetranychidae) is a widely distributed agricultural pest, and it possesses an exceptional capacity to withstand or adapt to short-term heat stress. To investigate the molecular mechanisms underlying this heat tolerance, using both transcriptome and whole-genome data, we identified six distinct POD genes in T. urticae and characterized their physicochemical properties and structural features. Real-time quantitative PCR (RT-qPCR) was utilized to analyze the expression profiles of these genes under short-term heat stress. Our results show that T. urticae mitigates heat-induced oxidative stress through the upregulation of POD gene expression, highlighting the critical role of these genes in the mite’s adaptive response to thermal stress. These findings contribute to a deeper understanding of the molecular pathways that enable T. urticae to survive in fluctuating thermal environments, which is increasingly relevant in the context of global climate change. Furthermore, this study provides a foundation for future research utilizing RNA interference (RNAi) technology to further investigate the functional roles of these POD genes and their potential as targets for pest control strategies. Full article

Rickettsiae are Gram-negative and obligate intracellular bacteria that cause rickettsioses. These pathogens are typically transmitted by arthropod vectors, such as ticks, mesostigmatid mites, and fleas. Rickettsiae are responsible for many emerging infectious diseases worldwide and are the second most frequently reported cause of non-malarial febrile illnesses in Southeast Asia. However, in Malaysia, studies on the prevalence and distribution of rickettsiae have primarily focused on humans, with limited data on these bacteria in vectors and small mammal hosts. Thus, this study aims to investigate the presence of Rickettsia spp. in small mammals and their associated mesostigmatid mites collected from potential rickettsioses areas in Selangor. Animal trapping was conducted across three different ecological study sites comprising a recreational area, agricultural land, and coastal area. A total of 41 small mammals and 363 mesostigmatid mites were collected and identified. Ten percent of the total individual mites were processed for morphological examination, and the remaining mites were then pooled by hosts, with five individual mites per tube, for DNA extraction. The collected samples, comprising blood, animal tissue, and pooled mites, were subjected to DNA extraction and were screened for Rickettsia spp. via nested polymerase chain reaction (PCR), targeting the citrate synthase-encoding gene (gltA) and outer membrane protein B gene (ompB). Interestingly, two pools (3.33%) of Laelaps spp. recovered from Maxomys whiteheadi and Bandicota indica, collected from a recreational area, tested positive for Rickettsia spp. Sequence analysis and phylogenetic tree of the ompB gene revealed the presence of Rickettsia felis in both laelapid mite pools. To our knowledge, this study provides the first molecular detection of R. felis in Laelaps spp. in Malaysia. Full article

Dermacentor nitens (tropical horse tick) is a tick species commonly found parasitizing horses and other equids in the Amazon region, causing economic losses. Currently, tick control is based on chemical acaricides, usually in a power formulation for topical use. However, its indiscriminate use results in the emergence of resistant tick lineages. Several plant compounds have been tested for their acaricide activity. In the Amazon, several plants are used for oil extraction, resulting in the production of solid residue (waste) that may contain chemical molecules with biological activities. Thus, we aimed to test the in vitro acaricidal potential of the ethanolic extract of the industrial residue of andiroba (Carapa sp.) against D. nitens. In a larval immersion test (LIT), D. nitens larvae were tested with 2.5%, 5%, and 10% andiroba extract concentrations in three replicates. Subsequently, the envelopes were kept in a BOD chamber (28 °C ± 1 °C; 80% ± 5% humidity) for 24 h. At the end of this period, live and dead larvae were counted, and efficiency was calculated from the mortality rate caused by the extract and corrected by the Abbot formula. In the three repetitions, the andiroba extract at a concentration of 5% caused the death of 100% of the larvae. At concentrations of 2.5% and 10%, they caused the death of, respectively, 12.38% (±3.5%) and 69.79% (±7.98%) of the larvae. These results indicate that the extract from the industrial residue from the production of andiroba oil has acaricidal activity. It is concluded that the solid waste from industrial andiroba oil extraction has the potential for the development of natural acaricides against D. nitens. Full article

We report the first case of flower bud galls in a species of the mainly American genus Senega (Polygalaceae), specifically in the South Andean Patagonian plant species S. salasiana. The galls were found to be induced by gall midges (Diptera, Cecidomyiidae) and mites (Acari). We also assessed their impact on plant reproduction by measuring the relationship between inflorescence density (number of inflorescences/plant cover) and gall abundance in two populations next to San Carlos de Bariloche, Patagonia, Argentina. Plant reproduction was negatively related to the number of galled inflorescences, suggesting that high levels of gall abundance strongly reduced plant reproductive success. Our study illustrates a novel case of flower galls in the genus Senega and highlights the negative impact of this type of herbivory on plant fitness. Full article