Mite Populations Research Articles

Resistance ratios and enzyme activity of Tetranychus urticae and Tetranychus turkestani (Acari: Tetranychidae) to commonly used acaricides on cotton in Aydin province, Türkiye

This study aims to determine the resistance ratios of Tetranychus urticae Koch red form (RF) and Tetranychus turkestani (Ugarov & Nikolskii) populations collected from cotton fields in Soke, Germencik, Kocarli and Nazilli districts of Aydin province to commonly used acaricides (abamectin, hexythiazox, etoxazole, spiromesifen). The potential role of detoxification enzymes (esterase, glutathione-s-transferase (GST), P450 monooxygenase (P450)) in acaricide resistance was also assessed. Overall populations of T. urticae RF presented varying ratios of resistance to these acaricides with all three populations (G15R21, K24R21, S3R21) showing significant resistance to abamectin (187.1–223.66 fold), hexythiazox (156.31–168.25 fold), etoxazole (409.58–517.20 fold) and spiromesifen (981.77–1246.11 fold). In contrast, all five T. turkestani populations (G4G21, K16G21, N1G21, N11G21, S19G21) were susceptible to abamectin, etoxazole, and spiromesifen, but exhibited some resistance to hexythiazox (164.34–182.39 fold). The resistance ratios of T. turkestani were however lower compared to T. urticae RF. A relationship was also found between detoxification enzymes and resistance. Esterase activity varied among mite populations, with the highest levels recorded in resistant populations of T. urticae (G15R21 and K24R219) with rates ranging between 6.48 and 7 mOD/min/mg protein. GST activity was highest in resistant mite populations (T. urticae S3R21 and T. turkestani K16G21). T. turkestani N11G21 population exhibited the highest P450 enzyme activity, reaching 4.39 RFU/30 min/mg protein. This study was the first to determine the resistance ratios of T. turkestani to hexythiazox in Türkiye, and on a global scale.

Transcriptome reanalysis and gene expression of 13 detoxification genes for avermectin and pyridaben resistance in Panonychus citri

Citrus red mites (P. citri) are key pests affecting citrus production worldwide due to pesticide resistance. The resistance mechanisms of ten pesticides are known, but a comprehensive study using transcriptome data is missing. This study employed deeptools, cuffdiff, rmats, bcftools and other software to examine gene expression variation, alternative splicing (AS), and mutations in mite resistance. The research highlighted that pesticides can regulate gene transcription, and red mites with resistance increase cytochrome P450, glutathione S-transferases, carboxylesterase, and acetylcholinesterase expression. Pyridaben also induces new AS events. Fluazinam-induced mites show mRNA splicing peaking earlier than transcription, both peaking at one day and returning to baseline after two days. AS profiles are similar in different mite populations with overlapping pesticide resistances. Lastly, specific mitochondrial SNPs in mites might mediate resistance against select pesticides.

Effect of Sowing Time on Infestation of Sucking Pests in Okra

Okra is highly susceptible to sucking pests like leafhopper, whitefly, and red spider mite, leading to significant yield losses. While farmers rely on insecticides for pest control, excessive use poses risk to the environment. To explore alternatives, a study was conducted at CCS Haryana Agricultural University, Hisar, during kharif 2023 to assess the effect of sowing time on sucking pests infestation in okra. For this, okra was sown on different times i.e., in the 3rd week of May, 1st and 3rd week of June, and 1st and 3rd week of July. The population of leafhopper, whitefly and red spider mite was recorded weekly, starting from the appearance of the pest. The study revealed that leafhopper population in crop sown in the 1st and 3rd week of July was on a par, however, significantly lower than that in other crops. Okra sown in the 1st week of July resulted in significantly lower population of whitefly than rest of the sowing times having population on a par with each other. Mite infestation was significantly lower in crop sown in the 3rd week of July compared to the others. Based on these findings, July appears to be the most suitable time for sowing okra to minimize sucking pests’ infestation.

Status of Invasive Species of Thrips, Thrips Parvispinus (Karny) Infesting Chilli and Investigation Studies on IPDM Package in Dharmapuri Districts, Tamil Nadu, India

Roving survey results revealed that mean population of thrips, mite population and tospovirus incidence was recorded to be 1.63, 0.68 & 2.05 and 1.88, 0.74 & 1.57 in Pennagaram and Palacode blocks. In the field experiments, mean population in the module I IPDM module was recorded low thrips population (1.05 nos./leaf and 0.64 nos/Sq.m2 leaves) followed by module II IPDM (1.11 Nos./leaf and 0.71nos/Sq.m2 leaves). A virus incidence of 1.0 to 2.0 % was recorded in treatment 2 module II and treatment 3 Farmers practices 2.2 to 9.5 % was observed. The per cent reduction over control of thrips and mite population is highest in T1 followed by T2 and farmer practice (81.70, 80.66 and 56.48 % & 79.61,77.38 and 33.12 %). The percent reduction over control of tospovirus by thrips is highest in T1 IPDM module followed IPDM II than farmer practice (100, 88.88 and 54.40%). The yield of green chilli and BC ratio were found to be high in IPDM module (22.96 t/ha and 3.02) followed by module II IPDM (19.14 t/ha and 2.78) followed by farmer’s practice (13.88 t/ha and 1.49).

Population Dynamics of the Mite Varroa destructor in Honey Bee (Apis mellifera) Colonies in a Temperate Semi-Arid Climate.

This study aimed to analyze the population dynamics of the mite Varroa destructor in honey bee (Apis mellifera) colonies in a temperate semi-arid climate in Mexico. Ten colonies homogeneous in population, food stores, and levels of mite infestation were used. The mite infestation rate in brood and adult bees, total number of mites, daily mite fall, brood and adult bee population, and food stores were determined periodically for 10 months. There was a significant effect (p < 0.05) of sampling period on the population of V. destructor in adult bees, brood, total mite population, and daily fallen mites. The total mite population increased by 26% on average per colony. The increase in brood amount reduced the mite infestation rate in adult bees, and the opposite occurred when the brood decreased. Monitoring V. destructor populations by recording fallen mites is more reliable than determining mite infestation rates in bees, as mite fall has a dynamic pattern similar to that of the total mite population. The best period to apply an acaricide treatment in the region of study is between November and December because most mites were in the phoretic phase, since there was less brood in the colonies compared to other times.

Evaluation of selected crops for rearing predatory mite (Phytoseiulus persimilis), a predator of two-spotted red spider mites

The damage caused by two-spotted spider mites, and the risks associated with chemical pesticides, including health and environmental risks necessitate the exploration of sustainable pest management methods. Predatory mites, such as Phytoseiulus persimilis, are effective biocontrol agents against pests like the two-spotted spider mite (Tetranychus urticae). Thus, this study aimed to evaluate the suitability of different crops for rearing predatory mites (Phytoseiulus persimilis) and assess their effectiveness in controlling two-spotted spider mites (Tetranychus urticae). Linear regression analysis showed significant effects of selected crops on mite populations across all collection times (Collection 1: F (3, 8) = 22.46, p = 0.0003; Collection 2: F (3, 8) = 11.45, p = 0.0029; and Collection 3: F (3, 8) = 9.17, p = 0.0057). ANOVA showed significant differences in mite counts among the crops (F (3, 32) = 18.06, p < 0.001), corroborated by bootstrapping analysis. Beans demonstrated the highest potential for supporting predatory mite populations, followed by eggplant and black nightshade, illustrating that crop diversification can enhance predatory mite production while suggesting adoption of Integrated pest management (IPM) strategies to reduce pesticide costs and environmental impacts. There is the need for collaborative research and policy support to drive innovation and promote sustainable pest management practices in agriculture, thus addressing pesticide-use related environmental issues.

SPATIAL ANALYSIS OF BROWN SPIDER MITE (Oligonychus punicae Hirst) DAMAGE IN AVOCADO USING SPATIAL ANALYSIS BY DISTANCE INDICES (SADIE)

Avocado (Persea americana Mill.) is a perennial crop that belongs to the Lauraceae family. This crop is affected by various pests, the most important of which is the spider mite Oligonychus punicae Hirst (Acari: Tetranychidae), also known as the brown avocado spider. The damage begins with reddish spots that spread throughout the leaf, eventually tanning the foliage and staining the fruit, resulting in its rejection in the market. As a result, understanding its spatial distribution is critical for growers to plan and implement integrated pest management programs effectively, reducing their economic and environmental impacts. This study used spatial analysis by distance indices (SADIE) to determine the spatial distribution of damage to the Hass avocado crop caused by brown spider mite populations in Coatepec Harinas and Donato Guerra, two municipalities in the State of Mexico, Mexico. Spatial behavior allows for the development of preventive or corrective control measures for the use of precision farming techniques. Spatial distribution maps were created using the geostatistical technique of ordinary Krigeing, and the mean and variance of damage caused by the brown spider mite in avocado were examined. The findings revealed a clustered spatial distribution with several aggregation centers that shift over time and correlate with the plots’ terrain and climate. No homogeneous pattern was found in any plot, indicating the need to continue this type of research to better understand concentration conditions and implement specific actions in the field.

Effects of Three Neonicotinoid Insecticides on the Development and Fecundity of Red Spider Mite: An age-stage two sex life table study

Red spider mite, Tetranychus urticae Koch, causes severe damage to economically important crops, fruits, vegetables, ornamentals etc. Management of red spider mite largely depends on chemicals. Application of insecticides may cause massive outbreaks of mite population. Sublethal effects of imidacloprid, thiamethoxam and acetamiprid doses were investigated on life-table parameters of red spider mite. All neonicotinoids revealed significant effects on life characteristics i.e. development duration and fecundity of red spider mite. Mites treated with imidacloprid, thiamethoxam and acetamiprid significantly reduced the net reproductive rate (Ro). No significant difference in finite rates of increase (λ) was observed among the treatments. Imidacloprid reduces the egg duration and mean generation time (T). Emerged adult longevity was shorter when exposed to insecticides. The total adult longevity was significantly reduced by the insecticides in comparison with the control. Highest mean generation time was observed in acetamiprid treated mites. The results suggested that sublethal effects of tested insecticides affected the biological parameters of red spider mite.

ProtectaBEE® and bee vectoring: innovating hive-based health with inspensing technology for sustainable apiculture

Apivectoring, or bee vectoring, employs managed bees to distribute powders containing disease and pest-fighting biocontrol agents during pollination flights to crops. Our research introduces a novel application of this concept, termed inspensing, which leverages bee vectoring for hive-based benefits. In inspensing, bees traverse through a carrier powder combined with products aimed at combating pathogens or pests within the hive. To facilitate this, we developed the ProtectaBEE® system, an innovative beehive-entrance technology that guides bees through a compartment inoculated with an inspensing powder. This system facilitates the application of beneficial agents into the hive without the need for beekeepers to open the hive, thereby streamlining the treatment process and reducing hive disturbance. To analyze the effectiveness of the system, we employed a fluorescent tracer in a powder formulation for tracking distribution throughout the hive. Complementing this, we inspensed a living dry powder-formulated biocontrol agent, Beauveria bassiana, an entomopathogenic fungus known to reduce Varroa mite populations, and detected its presence in the hive using PCR. The fluorescent powder was detected in 78.8% of the samples while B. bassiana was confirmed in up to 86.2% of larvae and 91.7% of mites. Our results underscore the system's efficacy in delivering material throughout the hive and affirm the potential for inspensing dry-powder-formulated biocontrol agents to manage Varroa destructor. Inspensing paves new paths for optimizing bee health and pest control strategies, streamlining disease management, simplifying hive maintenance, and minimizing beekeeper intervention, all contributing to sustainable apiculture.

The species, density, and intra-plant distribution of mites on red raspberry (Rubus idaeus L.).

The adoption of the European Green Deal will limit acaricide use in high value crops like raspberry, to be replaced by biological control and other alternative strategies. More basic knowledge on mites in such crops is then necessary, like species, density, and their role as vectors of plant diseases. This study had four aims, focusing on raspberry leaves at northern altitude: (1) identify mite species; (2) study mite population densities; (3) investigate mite intra-plant distribution; (4) investigate co-occurrence of phytophagous mites, raspberry leaf blotch disorder and raspberry leaf blotch virus (RLBV). Four sites in south-eastern Norway were sampled five times. Floricanes from different parts of the sites were collected, taking one leaf from each of the upper, middle, and bottom zones of the cane. Mites were extracted with a washing technique and processed for species identification and RLBV detection. Mites and leaves were tested for RLBV by reverse transcription polymerase chain reaction (RT-PCR) with virus-specific primers. Phytophagous mites, Phyllocoptes gracilis, Tetranychus urticae, and Neotetranychus rubi, and predatory mites, Anystis baccarum and Typhlodromus (Typhlodromus) pyri were identified. All phytophagous mites in cultivated raspberry preferred the upper zone of floricanes, while in non-cultivated raspberry, they preferred the middle zone. The presence of phytophagous mites did not lead to raspberry leaf blotch disorder during this study. RLBV was detected in 1.3% of the sampled plants, none of them with leaf blotch symptoms, and in 4.3% of P. gracilis samples, and in some spider mite samples, implying that Tetranychids could also be vectors of RLBV.

Heteromorphic deutonymph sex of the solitary bee parasite, Chaetodactylus krombeini (Baker) (Astigmata: Chaetodactylidae)

ABSTRACT Chaetodactylus krombeini (Acariformes: Astigmata: Chaetodactylidae) mites are kleptoparasites of solitary bees in the genus Osmia and depend on bee hosts for harbourage, nutrition, and dispersal, with infestations increasing morbidity and larval mortality. The life history traits of C. krombeini are unclear, complicating the control efforts of mites in managed bee nests. Mites in the family Chaetodactylidae have a facultative life stage, the heteromorphic deutonymph, used for either dispersal or dormancy when food resources are sparse. The heteromorphic deutonymph life stage is hypothesized to consist only of females, requiring arrhenotokous parthenogenesis to reproduce. This study examined this hypothesis by determining the sex of the adults that developed from each deutonymph morph. Phoretic deutonymphs were isolated after overwintering either with or without a bee host; inert deutonymphs were isolated from field collections from various locations. Mites were individually observed for 14 days, and development was recorded. Mites that reached adulthood were sexed. After 14 days, 32–38% of heteromorphic deutonymphs that reached adulthood were male. These results disprove the previous hypothesis that heteromorphic deutonymphs are exclusively female. The survival and reproductive strategies of C. krombeini are now in question, specifically the role of true arrhenotoky in founding new mite populations.

A bud's life: Metabarcoding analysis to characterise hazelnut big buds microbiome biodiversity

Despite Corylus avellana L. being an economically important shrub species known for its resilience to adverse environmental conditions, it constantly faces attacks from a plethora of biotic entities. Among these, the mite pest Phytoptus avellanae is gaining importance, causing economic losses every year. This mite colonises the new generative and vegetative buds, leading them to become swollen and reddish, and drastically reducing hazelnut production. The biology behind gall formation is still poorly understood. This study provides a qualitative and quantitative description of the microbiome in both healthy and infested buds of two economically important hazelnut cultivars through metabarcoding of fungal ITS and bacterial 16 S. Potentially pathogenic genera such as Fusarium and Pseudomonas were predominant in the infested buds, along with the obligate intracellular bacterial genus Wolbachia. Akanthomyces muscarius was instead isolated from culture-based methods only from the infested buds. These findings could improve the understanding of gall ecology, supporting the management of mite populations, and they could also serve as a milestone for further studies on low-impact, monitoring-driven, and genetically targeted control strategies.

Prevalence of Tetranychus urticae Koch and T. turkestani (Ugarov & Nikolskii) (Acari: Tetranychidae) and their endosymbiotic bacteria in cotton fields of Aydin, Türkiye

Spider mites are important pests of cotton, a vital fiber crop cultivated in sun-drenched regions. This study investigated the prevalence and distribution of spider mite species infesting cotton fields in Aydin province, Türkiye. Spider mites were found in a significant portion (89%) of the surveyed fields. The two most abundant mite species, were the red form (RF) of Tetranychus urticae (57.1%) and T. turkestani (39.3%). A minor presence of T. urticae green form (GF) (3.6%) was observed. Tetranychus urticae RF was more prevalent in coastal areas, while T. turkestani was more common inland. Field surveys demonstrated that areas with higher T. urticae RF prevalence exhibited more frequent spraying, potentially due to this species’ greater capacity to develop resistance compared to T. turkestani. This study also investigated the prevalence of Wolbachia, Rickettsia, Cardinium and Spiroplasma endosymbionts, which are linked with pesticide resistance due to their ability to degrade pesticides, in these mite populations. The study confirmed the presence of Wolbachia and Rickettsia endosymbionts in spider mite populations in Türkiye. However, no Cardinium or Spiroplasma were detected in any of the populations. Infection rates of the detected endosymbionts differed between T. urticae and T. turkestani. Future studies should investigate the resistance levels of these tetranychid mite species as well as the role of their endosymbiotic bacteria in resistance in cotton-growing areas.

Determination of target site mutations and detoxification enzymes in the abamectin resistance of spider mite Tetranychus urticae collected from cotton fields of Türkiye

The two-spotted spider mite, Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) causes significant problems in cotton fields. The pest has developed resistance to abamectin, which is used intensely against spider mite populations. A discriminating dose was applied to T. urticae populations collected from Aydın, Adana, Şanlıurfa, and Diyarbakır provinces between 2019 and 2021, where there is significant cotton production and intensive acaricide applications. Populations with a mortality rate of less than 80% at the discriminating dose applied to field populations were included in the bioassay study. Then, the 10 most resistant populations were determined based on their LC50 and LC90 values. It was observed that there was high resistance (HR) in two T. urticae populations collected from Diyarbakır (DIY28 and DIY2) with LC50 values of 24.5 and 33.81 mg L-1, respectively 113 and 156-fold and one population collected from the province of Aydın (AYD4) LC50 value of 23.5 mg L-1 and 109-fold. As a result of the comparisons with a susceptible population in biochemical studies, it was determined that the carboxylesterase (CarE) enzyme of these populations (except for SAN6, SAN7, SAN8, ADA9, and ADA11) had more than 2-fold higher activity compared to the glutathione enzyme (GST), and they were in statistically different groups. When the GST enzyme activities were examined, it was found that the enzyme activities were generally low, except for the ADA11 and ADA16 populations (3.73 and 2.3-fold). In terms of the target site resistance, it was observed that there was no target site mutation (G314D and I321T-G326E) in the glutamate-gated chloride channels (Units GluCl 1 and 3) in these highest 10 resistant populations. It can be said that the resistance levels determined for abamectin from the obtained populations were determined to be low. In brief, out of the total 44 populations brought in and tested, only 30 populations were considered resistant with a mortality rate below 80% after the applied discriminating dose. It was determined that 6.8% of these 30 populations had HR, 31.8% had medium resistance (MR), and 29.5% had low resistance (LR). When examining by regions, it was found that high resistance populations were more prevalent in Diyarbakır and Aydın (15.4% and 10%, respectively) provinces, while the highest percentage of MR populations was found in Şanlıurfa, at 90%. Abamectin still acts as an effective acaricide. However, it is recommended to use acaricides with different modes of action to prevent possible emergence of resistance cases.

Comparative evaluation of biological control programs and chemical pesticides for managing insect and mite pests in cucumber greenhouses: a sustainable approach for enhanced pest control and yield

BackgroundCucumber plants are susceptible to several economically damaging pests, including whiteflies, aphids, thrips and spider mites. This study aimed to evaluate the efficacy of two biological control programs, utilizing different releases of bio-agents, in comparison with chemical control method. The bio-agents used were the aphid parasitoid Aphelinus albipodus Hayat and Fatima (Hymenoptera: Aphelinidae), the green lacewing Chrysoperla carnea (Steph.) (Neuroptera: Chrysopidae) and the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) in two release rates; low and high. Additionally, a chemical pesticides treatment was included for comparison in managing the pests in cucumber greenhouses during the winter seasons of 2022 and 2023, in Egypt. Abundances of whitefly, aphids, thrips and spider mites were recorded weekly throughout the study.ResultsThe aphid population in the greenhouse with high release rate (BIO 2) showed the highest reduction, with percentages of 84.55 and 89.88% in 2022 and 2023, respectively. Both greenhouse with low release rate (BIO 1) and BIO 2 exhibited significant reductions in the whitefly population, with proportions of 71.31 and 72.01% in 2022, and 82.05 and 85.94% in 2023, respectively. The thrips population also experienced notable reductions in both BIO 1 and BIO 2 greenhouses, with percentages of 72.08 and 75.71% in 2022, and 59.93 and 61.38% in 2023, respectively. However, the pesticide treatment demonstrated the lowest reduction in populations of aphids, whitefly and thrips in both seasons. Nevertheless, in all treatments in the two evaluated seasons, the high release rate of the predatory mite, P. persimilis (15 individuals/m2), proved to be highly effective in maintaining the mite populations below the economic threshold level. However, the population density of the two-spotted spider mite, Tetranychus urticae Koch. (Acari: Tetranychidae), increased in the pesticide-treated greenhouse, indicating the development of resistance to pesticides. Although the tested programs resulted in similar yields, the biological control approach offered the advantage of pesticide-free produce and reduced production costs.ConclusionFor pest management in cucumber growing in greenhouses during winter, it is recommended to use biological control agents at a low release rate at the early occurrence of pests. This approach can help minimize pest populations effectively.

Phytoseiid mites benefited from organic fertilization by increasing the population of Tyrophagus mites in apple orchards

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.

Varroa Mite Counting Based on Hyperspectral Imaging.

Varroa mite infestation poses a severe threat to honeybee colonies globally. This study investigates the feasibility of utilizing the HS-Cam and machine learning techniques for Varroa mite counting. The methodology involves image acquisition, dimensionality reduction through Principal Component Analysis (PCA), and machine learning-based segmentation and classification algorithms. Specifically, a k-Nearest Neighbors (kNNs) model distinguishes Varroa mites from other objects in the images, while a Support Vector Machine (SVM) classifier enhances shape detection. The final phase integrates a dedicated counting algorithm, leveraging outputs from the SVM classifier to quantify Varroa mite populations in hyperspectral images. The preliminary results demonstrate segmentation accuracy exceeding 99% and an average precision of 0.9983 and recall of 0.9947 across all the classes. The results obtained from our machine learning-based approach for Varroa mite counting were compared against ground-truth labels obtained through manual counting, demonstrating a high degree of agreement between the automated counting and manual ground truth. Despite working with a limited dataset, the HS-Cam showcases its potential for Varroa counting, delivering superior performance compared to traditional RGB images. Future research directions include validating the proposed hyperspectral imaging methodology with a more extensive and diverse dataset. Additionally, the effectiveness of using a near-infrared (NIR) excitation source for Varroa detection will be explored, along with assessing smartphone integration feasibility.

Evaluation of three different bottom boards in honeybee hives for the control of Varroa destructor

IntroductionVarroa destructor stands as the primary global pest of honey bees, inflicting direct harm on bees while also acting as a vector for a multitude of viruses. Integrated pest management is widely recognized as the optimal strategy for minimizing acaricide application. Designed bottom boards that can limit the growth of the mite population by removing them from the hive and preventing their return and reinfestation of the colony show promising potential.MethodsThe aim of this study was to compare Varroa population growth by employing three different types of bottom boards. An apiary of 55 colonies was randomly divided into five groups according to the bottom board they had: 1) tubular bottom board, 2) screen bottom board, 3) sticky bottom board, 4) conventional bottom board with a permanent treatment with acaricide (positive control), and 5) conventional bottom board (negative control). Varroa infestation level in bees, colony strength (bee and brood population), and honey reserves were determined between April and December (between autumn and spring in the southern hemisphere).ResultsColonies that had sticky bottom boards had approximately 50% less Varroa infestation than colonies with conventional bottom boards at the end of the study. Varroa infestation levels did not differ significantly between the tubular, screen, and conventional bottom boards. Colony strength was similar in all groups. No differences were observed in honey production between colonies from different groups.DiscussionThe use of sticky bottom boards was the most promising board to limit Varroa population growth and prevent colonies' reinfestation. This result encourages future studies to analyze the incorporation of this strategy in integrated pest management programs.

Effectiveness and safety of demodecosis blepharitis therapy under dry eye conditions

Purpose: to evaluate the effectiveness and safety of complex therapy in patients with demodex blepharitis and dry eye. Methods. 25 patients with mixed demodex blepharitis and dry eye (50 eyes; 10 men, 15 women; 61.9 ± 5.6 years) were examined before and after treatment with 0.5 % levofloxacin instillation (5 times a day, 5 days); sulfur and metronidazole gel applications (Blefarogel-forte) as part of therapeutic eyelid hygiene (Blepharogel-cleansing, Blepharolotion; starting from day 6, 2 times a day, 45 days); 0.24 % sodium hyaluronate instillation (3 times a day). Therapy effectiveness criteria were as follows: D. folliculorum mite population reduction; positive dynamics of blepharitis objective signs and meibomian gland dysfunction severity (MGD-S, points). Therapy safety criteria included the absence of negative dynamics of OSDI, tear film breakup time (TBUT, s), inferior tear meniscus height (ITMH, µm) and xerosis index (XI, points). Results. As a result of the therapy, statistically significant changes were noted, including mite population reduction (from 9.23 ± 0.81 to 3.54 ± 0.80 imagos); eyelid margins edema intensity decrease (from 3.18 ± 0.39 to 1.30 ± 0.45 points) and hyperemia decrease (from 2.90 ± 0.29 to 0.9 ± 0.3 points); MGD-S decrease (from 2.1 ± 0.3 to 0.95 ± 0.21 points); OSDI decrease (from 43.23 ± 4.70 to 25.10 ± 2.65 points); TBUT increase (from 4.05 ± 0.50 to 5.55 ± 0.50 s); XI decrease (from 5.36 ± 0.49 to 4.04 ± 0.60 points). Conclusion. The treatment of demodex blepharitis and dry eye treatment, including sulfur and metronidazole gel applications, therapeutic eyelid hygiene and 0.5 % levofloxacin and 0.24 % sodium hyaluronate instillation demonstrated a high efficiency and a good safety profile.

Interspecific interaction network of mites associated with mango trees.

Direct and indirect ecological interactions, environmental factors, and the phenology of host plants can shape the way mites interact. These relationships interfere with species occurrence and consequently alter the structure and stability of the intraplant community. As predatory mites act as regulators of herbivorous mites, we hypothesized that these mites may occupy a central position in a network of interactions among mite species associated with mango trees, and the occurrence of these species is mediated by environmental variables and the phenological stage of the host plant. We evaluated the global structure of the interaction network of mites associated with individual Mangifera indica plants and analyzed the interspecific relationships of the species using an undirected Bayesian network approach. Additionally, we observed a correlation between mite population density and plant phenological stage. Environmental variables, such as average monthly temperature, monthly precipitation, and average monthly relative humidity at different sampling date were used in the correlation analysis. The modularity at the mite-plant network level showed a low specialization index H2 = 0.073 (generalist) and high robustness (R = 0.93). Network analysis revealed that Amblyseius largoensis, Bdella ueckermanni, Parapronematus acaciae, and Tuckerella ornata occupied central positions in the assembly of mites occurring on mango trees. Environmental variables, average monthly temperature, and monthly precipitation were correlated with the occurrence of Brachytydeus formosa, Cisaberoptus kenyae, Oligonychus punicae, T. ornata, and Vilaia pamithus. We also observed a correlation between the plant phenological stage and population densities of Neoseiulus houstoni, O. punicae, P. acaciae, and V. pamithus.