Mite Populations Research Articles

Varroa mite and deformed wing virus infestations interactively make honey bees (Apis mellifera) more susceptible to insecticides

Varroa mite is one of the major adverse factors causing honey bee population decline. In this study, Varroa destructor-infested and uninfested honey bee colonies were established by selective applying miticide (Apivar® amitraz). Mite population was monitored monthly (April–October 2016), and deformed wing virus (DWV) loading was detected seasonally (April, July, and October). Four immunity- and two physiology-related gene expressions, natural mortality, and susceptibility to five insecticides were comparatively and seasonally examined in field-collected honey bee workers. Results showed that Apivar-treated bee colonies had minor or undetectable mite and DWV (using RT-qPCR) infestations in whole bee season, while untreated colonies had substantially higher mite and DWV infestations. In untreated colonies, Varroa mite population irregularly fluctuated over the bee season with higher mite counts in Jun (318 ± 89 mites dropped in 48 h) or August (302) than that (25 ± 4 or 34) in October, and mite population density was not dynamically or closely correlated with the seasonal shift of honey bee natural mortality (regression slope = −0.5212). Unlike mite, DWV titer in untreated colonies progressively increased over the bee season, and it was highly correlated (R2 = 1) with the seasonal increase of honey bee natural mortality. Significantly lower gene expressions of dor, PPO, mfe, potentially PPOa and eat as well, in untreated colonies also indicated an association of increased DWV infestation with decreased physiological and immunity-related functions in late-season honey bees. Furthermore, bees with lower mite/DWV infestations exhibited generally consistently lower susceptibilities (contact and oral toxicities) to five representative insecticides than the bees without Apivar treatment. All of these data from this study consistently indicated an interaction of Varroa/viral infestations with insecticide susceptibilities in honey bees, potentially through impairing bee's physiology and immunity, emphasizing the importance of mite control in order to minimize honey bee decline.

Combined effects of oxalic acid sublimation and brood breaks on Varroa mite (Varroa destructor) and deformed wing virus levels in newly established honey bee (Apis mellifera) colonies

Annual losses of honey bee colonies are high in the United States, with losses often attributed to the effects of the ectoparasitic mite, Varroa destructor, and its associated viruses (e.g., Deformed Wing Virus, DWV). In the spring, beekeepers rely on package bees to replace lost colonies. However, these packages often come with high levels of mites and are treated with miticides upon installation. Oxalic acid (OA) is a popular miticide used in spring, but little is known about its long-term efficacy for mite control. On the other hand, natural behavior that helps with mite control is swarming, which results in a break in the production of brood in a colony. In this study, we investigated the effect of spring OA sublimation and summer swarming on colony health and productivity. We found that OA sublimation is an effective method to increase mite drop from the colony in the first three days after treatment. However, mite populations recovered quickly leading to high mite levels in the fall for colonies that did not swarm during the summer. OA applications had a marginally significant negative effect on honey yield. Mid-season swarming was correlated with lower levels of Varroa mites suggesting that implementing a brood break in the middle of the summer could play an important role in reducing mite populations for colonies originating from packages. However, the combination of OA applications to packages in the spring and summer brood break had a significant effect on reducing mite levels for colonies entering the winter. We conclude that treating packages with OA in the spring in combination with summer mite treatments are powerful tools for beekeepers to keep colonies with lower pest loads entering the winter.

Inducción de tolerancia a Globodera spp. con microorganismos promotores de crecimiento en el cultivo de papa (Solanum tuberosum subsp. tuberosum)

The effect of inducing tolerance to the attack of Globodera spp. was tested using three fungi (Trichoderma, Pochonia and Pleurotus) and a bacterium (Bacillus), as growth-promoting microorganisms (PGPR) in potato variety Desiree under greenhouse conditions. Cysts were extracted from the infested soil, from the Municipality of Pocona, 25 cysts were infested in each pot during planting, after 30 days the growth-promoting microorganisms PGPR, strains from FCAyP, were inoculated. The research was carried out under a completely randomized design, with 15 treatments and two controls (absolute control and control with nematode), with 8 repetitions. The evaluations were carried out at 70 days, considering the physiological variables: fresh weight of the foliage, and fresh weight of the root, and at 90 days after harvest, the Nematological variables (final population), Agronomic variables (number of tubers and yield) and analysis of mesofauna (population of collembola and mites). The application of growth promoting microorganisms PGPR helped to induce tolerance to the attack of Globodera spp. and also on the physiology of the plant, which was manifested in the crop yield, being two fungi (Pochonia + Pleurotus) combined, they act synergistically helping the plant to tolerate the attack of the nematode, increased by 20% of yield, still being attacked by the plague. Additional Key Words: Microorganisms, PGPR, Tolerance, Globodera spp, Fungi, Bacteria.

Brevipalpus mites associated with coffee plants (Coffea arabica and C. canephora) in Chiapas, Mexico.

Tenuipalpid mites of the genus Brevipalpus are of significant economic and quarantine importance in agriculture. They can damage and vector phytopathogenic viruses in coffee plantations and other crops. In this study, we focused on: identification of the Brevipalpus species, assessment of the spread of Brevipalpus-associated viruses (CoRSV, CiLV-N, CiLVC and CiLVC2), and mite population fluctuations over the course of 1year. The study was conducted in coffee plantations in Soconusco, a coffee-producing region in Chiapas, Mexico. The collected mites of the Brevipalpus phoenicis sensu lato species complex (635) were identified as Brevipalpus papayensis (80.2%) and B. yothersi (19.8%) based on morphological and molecular characteristics. Their population abundance was low and there were no indications for virosis. The highest mite abundance was recorded in August-September and the lowest in February-March. An interaction was observed between mite abundance and coffee species in open-growth and shaded cultivation at various altitudes. Brevipalpus papayensis was most abundant in Coffea arabica var. Bourbon, in shaded (80%) growing conditions at an altitude of 1300m above sea level. In C. canephora (in open-growth cultivation conditions at low altitude), B. yothersi was more abundant than in C. arabica, and as abundant as B. papayensis. We are of the opinion that, at this moment, B. papayensis and B. yothersi do not present risks to the production of coffee for the studied plantations. However, as the coffee-producing regions of Mexico are ecologically diverse, it will be important to continue examining the status of Brevipalpus mite populations in other regions in Mexico.

Cardinium inhibits Wolbachia in its mite host, Tyrophagus putrescentiae, and affects host fitness.

Interactions among endosymbiotic bacteria inside their eukaryotic hosts are poorly understood, particularly in mites. The mite Tyrophagus putrescentiae is a common, medically important generalist species that has many intracellular and gut bacterial symbionts. In the experiments, we examined bacterial abundances and composition in mite populations obtained by controlled mixing of stock mite populations that differed in the presence/absence of the major intracellular bacteria Wolbachia and Cardinium. Changes in microbial communities were characterized using 16S ribosomal RNA high-throughput sequencing (pooled mite individuals) and quantitative PCR for key microbial taxa (individual mites). Mite fitness was estimated as a parameter of population growth. We detected that in mixed mite populations, Cardinium and Wolbachia can co-occur in the same mite individual. The presence of Cardinium was negatively correlated with the presence of Wolbachia and Bartonella, while the Bartonella and Wolbachia were positively correlated in individual level samples. Since mixed populations had lower abundances of Wolbachia, while the abundance of Cardinium did not change, we suggest that the presence of Cardinium inhibits the growth of Wolbachia. The mixed mite populations had lower population growth than parental populations. The possible effect of symbionts on the fitness of mixed population is discussed.

Label-free proteomic analysis reveals differentially expressed Wolbachia proteins in Tyrophagus putrescentiae: Mite allergens and markers reflecting population-related proteome differences

Tyrophagus putrescentiae is an astigmatid mite of great economic, medical and veterinary importance. The microbiome, especially intracellular bacteria, may affect allergy/allergen expression. We targeted Wolbachia proteins, allergen comparisons and markers in Wolbachia–mite interactions in three mite populations. A decoy database was constructed by proteogenomics using the T. putrescentiae draft genome, Wolbachia transcriptome assembly and current T. putrescentiae-related sequences in GenBank. Among thousands of mite-derived proteins, 18 Wolbachia proteins were reliably identified. We suggest that peroxiredoxin, bacterioferritin, ankyrin repeat domain-containing protein and DegQ family serine endoprotease indicate a higher-level bacterium–bacterium–host interaction. We produced evidence that the host–Wolbachia interaction is modulated through pattern recognition receptors (PRRs), mannose-binding lectins/mannose receptors, the cholinergic anti-inflammatory pathway with TNF-α, and others. We observed Tyr p 3 suppression in mites with Wolbachia, linking trypsin to PRR modulation. Nine out of the 12 current WHO/IUIS official allergens were reliably identified, but the remaining three allergens, Tyr p 1, 8 and 35, were detected as only trace hits. This study provides numerous markers for further Wolbachia–host interaction research. For accuracy, mite allergens should be considered according to abundance in species, but mite populations/strains, as well as their microbiome structure, may be key factors. SignificanceThe astigmatid mites occurring in homes are significant producers of allergens that are highly dangerous to humans and domesticated animals. Mites are tightly associated with microorganisms that affect their biology and consequently allergy signatures. Mite populations were found to be infected with certain intracellular bacteria, but some populations lacked an intracellular bacterium. Our previous research showed that some populations of Tyrophagus putrescentiae are infected with Wolbachia, but some populations host additional bacteria of interest. Thus, there are not only interactions between the mites and Wolbachia but also likely an additional level of interaction that can be found in the interaction between different bacteria in the mites. These “higher-level” signatures and consequences that bacteria affect, including allergen production, are not understood in mites. In this study, we identified Wolbachia-specific proteins in mites for the first time. This study provides Wolbachia- and mite-derived markers that can be clues for describing “higher-level” mite-bacterium-bacterium interactions. Indeed, the microbiome contribution to allergies can potentially be derived directly from bacterial proteins, especially if they are abundant.

Residual Tau-Fluvalinate in Honey Bee Colonies Is Coupled with Evidence for Selection for Varroa destructor Resistance to Pyrethroids.

Simple SummaryVarroa destructor is one of the most prevalent honey bee (Apis mellifera) pathogens worldwide. Nowadays, the main method to control this parasite involves the application of different acaricidal treatments, among which the pyrethroid tau-fluvalinate is one of the most widely used. However, the intensive and repetitive application of these chemicals generates a selective pressure that, when maintained over time, contributes to the emergence of resistant mites in the honey bee colonies. Here we analysed the presence of residual tau-fluvalinate and the patterns of genetic resistance to this acaricide in Varroa mites collected from tau-fluvalinate untreated honey bee colonies. Our results show the widespread and persistent pyrethroid contamination of beeswax and beebread in the hives, along with an excess of pyrethroid-resistant genotypes and an overall increase in the frequency of the pyrethroid-resistant allele in the mite population over time. Persistent contamination of the hives likely compromises the efficacy of tau-fluvalinate treatments and, therefore, may have serious long-term consequences for the control of varroosis.Varroa destructor is considered one of the most devastating parasites of the honey bee, Apis mellifera, and a major problem for the beekeeping industry. Currently, the main method to control Varroa mites is the application of drugs that contain different acaricides as active ingredients. The pyrethroid tau-fluvalinate is one of the acaricides most widely used in beekeeping due to its efficacy and low toxicity to bees. However, the intensive and repetitive application of this compound produces a selective pressure that, when maintained over time, contributes to the emergence of resistant mites in the honey bee colonies, compromising the acaricidal treatments efficacy. Here we studied the presence of tau-fluvalinate residues in hives and the evolution of genetic resistance to this acaricide in Varroa mites from honey bee colonies that received no pyrethroid treatment in the previous four years. Our data revealed the widespread and persistent tau-fluvalinate contamination of beeswax and beebread in hives, an overall increase of the pyrethroid resistance allele frequency and a generalized excess of resistant mites relative to Hardy–Weinberg equilibrium expectations. These results suggest that tau-fluvalinate contamination in the hives may seriously compromise the efficacy of pyrethroid-based mite control methods.

Natural and Synthetic Repellents for Pest Management of the Storage Mite Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae).

Simple SummaryThe ham mite is the major pest of dry-cured hams, aged cheeses, and specialty pet foods that are high in fats and proteins. Ham mites are also known to cause allergies in some cases for humans. The toxic fumigant gas methyl bromide had been used for years to control this mite pest, but it is being phased out of use due to its impact on the protective ozone layer of the earth’s upper atmosphere. Ham producers now require alternatives to methyl bromide for controlling mites. We conducted laboratory experiments with food-safe synthetic and plant-derived chemical repellents to keep mites away from dry cured hams. Our results showed that several of these repellents could effectively prevent ham mites from contacting and staying on treated pieces of ham, and that they would readily go to untreated ham pieces when given a choice. Further experiments found that mites would not feed on nor produce offspring when held on ham pieces coated with oils from thyme, lemon grass, rose, or a mixture of naturally occurring fat molecules. Our experiments suggest that these food-safe repellents might protect dry-cured hams from mites during their time in aging rooms by application to racks on which hams are aged or to the nets and packaging in which hams are held.The fumigant pesticide methyl bromide (MB) was used for stored products, but it is now banned for most uses in many countries as an ozone-depleting substance. MB was the only pesticide used to manage the ham mite, Tyrophagus putrescentiae, which is the most significant pest of dry cured hams. Effective alternatives to MB are needed to develop integrated pest management (IPM) programs for this pest. This study evaluated plant essential oils and food-safe compounds as repellents to directly protect hams from infestation. Experiments to assess the repellency to orientation, oviposition, and population growth of mites on pieces of aged country hams were conducted. Test compounds at different concentrations were dissolved in respective solvents and compared to the solvent control. Results showed that C8910, a mixture of three short-chain fatty acids, and the sesquiterpene ketone nootkatone had repellency indices of (RI) of 85.6% and 82.3%, respectively, at a concentration of 0.1 mg/cm2, when applied to a Petri dish arena. DEET and icaridin were also tested but performed poorly with RIs below 70% even at 0.1 mg/cm2.The monoterpene alcohol geraniol had the highest RI of 96.3% at 0.04 mg/cm2. Ham pieces dipped in C8910 and nootkatone at 150 ppm each had RIs of 89.3% and 82.8%, respectively. In general, as the concentrations of test compounds increased, the numbers of eggs that were laid on these treated ham cubes decreased after the 48 h exposure time. Ham pieces dipped in different concentrations of test compounds and then inoculated with 20 adult mites showed a significant decrease in mite population growth compared to control pieces after 14 days. The results of these experiments suggest that some plant secondary metabolites and synthetic food-safe compounds could serve as potential alternatives for managing mites on hams.

МОДИФИКАЦИИ ПРИЕМОВ РАЗВЕДЕНИЯ КЛЕЩЕЙ PHYTOSEIIDAE ДЛЯ ПОДАВЛЕНИЯ ЧИСЛЕННОСТИ ПАУТИННОГО КЛЕЩА

Populations of mites from the Tetranychidae family are characterized as high-resistant to acaricides, which, in turn, leads to an increase in the pesticide load on the agrocenoses ecosystem. Carnivorous arthropods from the Phytoseiidae family can be used as an alternative pest control. Our research aimed at improving the methods of breeding, storage and use of predatory mites against Tetrahychus urticae Koch. In 2015–2018, work was being undertaken to define the optimum thickness of the substrate layer (2.0, 4.0 and 6.0 cm) for breeding the food object – Acaris farus Oud. We also assessed the effect of the fodder substrate composition (wheat bran – control, wheat bran + soybean meal – experimental variant) on the population density of Amblyseius andersoni Chant. In 2016–2019, experiments on the storage of Neoseiulus barkeri Hughes, Neoseiulus cucumeris Oud. and Amblyseius swirskii Athias-Henriot at 4 °C (control – no storage) were carried out. In 2018–2019, to control Tetrahychus urticae Koch. in the soybean field, a mixture of N. cucumeris and A. andersoni was used according to the method of introduction into natural foci of prey. The optimum thickness of the substrate layer was found to be 4 cm. In this case, it was possible to obtain 6,983 mites in 1 cm3 for 7 days. Soybean meal addition increased the number of A. andersoni by 22.3 % compared to control (263 ind. vs 204 ind. per cm3). 30–45 days – an effective storage period for N. barkeri, 30 days – for N. cucumeris, no more than 10 days – for A. swirskii. On average, in 2018–2019, N. cucumeris and A. andersoni mixture reduced the number of T. urticae. The number of spider mites in the control variant was 14.6, in the experimental one – 5.3 ind./leaf. No predatory activity was observed on eggs. To prevent the development of spider mites, it is necessary to use N. cucumeris and A. andersoni at least twice with an interval of 5–7 days.

Nationwide Incidence of Chigger Mite Populations and Molecular Detection of Orientia tsutsugamushi in the Republic of Korea, 2020.

The Korea Disease Control and Prevention Agency has established regional centers at 16 locations to monitor vectors and pathogens. We investigated the geographical and temporal distribution of chigger mite populations to understand tsutsugamushi disease epidemiology in 2020. To monitor weekly chigger mite populations, 3637 chigger mites were collected from sticky chigger mite traps in autumn. Chigger mites appeared from the first week of October to the third week of December, peaking in the fourth week of October. The predominant species were Leptotrombidium scutellare, Leptotrombidium palpale, Neotrombicula kwangneungensis, Neotrombicula tamiyai, and Leptotrombidium pallidum. To monitor Orientia tsutsugamushi infection in chigger mites, 50,153 chigger mites were collected from 499 trapped wild rodents in spring and autumn, with a chigger index of 100.5. Approximately 50% of chigger mites were pooled into 998 pools, and the minimum infection rate (MIR) of O. tsutsugamushi was 0.1%. Jeongeup had the highest MIR for O. tsutsugamushi (0.7%). The Kato-related genotype was the most common (52.2%), followed by the Karp-related (17.4%), Boryong (13.0%), JG-related (8.7%), Shimokoshi (4.3%), and Kawasaki (4.3%) genotypes. Ecological and geographical studies focusing on the basic ecology and pathology of mites will improve our understanding of tsutsugamushi disease risks in the Republic of Korea.

Assessment of Bio-efficacy of Insecticides against Mites and Thrips Insect Pest of Chilli

A field experiment was conducted during kharif 2018-19 in Samajik Vigyan Kendra, Dr. B.R. Ambedkar University, Bordi, Sehore (M.P.) – INDIA. To assess the bio-efficacy of insecticides against mites and thrips insect pest of chilli pests. The bio-efficacy of three different insecticides, namely (i) Chlorfenapyr 240 SC - spray four time with different-different doses, (ii) Fipronil 5% SC and (iii) Imidacloprid 17.8 SL. One untreated plot was also used to investigate against Mites and Thrips. Among these insecticides, Chlorfenapyr 240SC doses 288 g.a.i/hac gram active ingredient per hactare) has reduced maximum mites and thrips population and it is most effective insecticides in chilli. The highest reduction of mites population recorded in treatment T4- (97.17%) followed by T3- chlorofenapyr (95.13%), T6- Imidacloprid (91.67%), T5- Fipronil 5% SC (85.35%), T2- chlorofenapyr (85.27%) and it was least in T1- chlorofenapyr (81.40%. Further, the thrips number was maximum reduced in treatment T4- chlorofenapyr (90.69%) followed by T3- chlorofenapyr (89.80%), T5- Fipronil 5% SC (89.51%), T6- Imidacloprid (74.18%), T2- chlorofenapyr (69.74%) and T1- chlorofenapyr (68.44 %). Hence, present study was clearly indicated that the treatment T4- chlorofenapyr 240SC@288 proved, the most effective insecticides. The cost benefit ratio was noted higher in Fipronil 5% SC@ 10 g.a.i ha-1 (3.20) followed by imidacloprid 17.8 SL @ 50 g.a.i ha-1 (2.99).

Production of Akanthomyces lecanii by submerged fermentation to control Tetranychus urticae (Acari: Tetranychidae) in Gerbera jamesonii crops

ABSTRACT In Colombia, the Tetranychus urticae mite (Acari: Tetranychidae) is one of the most challenging phytosanitary issues faced by flower cultivators. The control of this mite has been commonly done through the use of chemical insecticides. But the mites have generated resistance to these substances over time, making their handling more difficult. Some sustainable alternatives based on the use of biological control agents (BCA) can also be implemented in the control of T. urticae. The fungus Akanthomyces lecanii has proved to be effective in the control of T. urticae, however, is conventionally produced by solid-state fermentation (SSF) with low yields and high costs. Submerged fermentation (SmF) is a successful alternative that increases yields and reduces times in BCA production. In this research, the conditions for the production of A. lecanii by SmF were determined to improve the control of T. urticae in the Gerbera jamesonii. The percentage of immobile T. urticae adults, and the median lethal time (LT50) values, were evaluated. Also, some low molecular weight compounds were extracted and detected by liquid chromatography coupled with high-resolution mass spectrometry. The concentration of A. lecanii produced in SmF was 132 times higher than that obtained from SSF and, better control of mite populations was observed both in vitro and in the field. These results show that the production of A. lecanii by SmF can be a more efficient alternative to implement comprehensive control strategies in flower crops.

Field Assessment of the Host Range of Aculus mosoniensis (Acari: Eriophyidae), a Biological Control Agent of the Tree of Heaven (Ailanthus altissima).

Tree of heaven (Ailanthus altissima) is a fast-growing deciduous tree native to China, considered a serious invasive species worldwide, with several socio-economic and ecological impacts attributed to it. Chemical and mechanical methods have limited efficacy in its management, and biological controls may offer a suitable and sustainable option. Aculus mosoniensis (Ripka) is an eriophyid mite that has been recorded to attack tree of heaven in 13 European countries. This study aims to explore the host range of this mite by exposing 13 plant species, selected either for their phylogenetic and ecological similarity to the target weed or their economic importance. Shortly after inoculation with the mite, we recorded a quick decrease in mite number on all nontarget species and no sign of mite reproduction. Whereas, after just one month, the population of mites on tree of heaven numbered in the thousands, irrespective of the starting population, and included both adults and juveniles. Significantly, we observed evidence of damage due to the mite only on target plants. Due to the specificity, strong impact on the target, and the ability to increase its population to high levels in a relatively short amount of time, we find A. mosoniensis to be a very promising candidate for the biological control of tree of heaven.

The Presence of House Dust Mites in Residences and Classrooms of Students with Allergic Rhinitis

Allergy is still a health problem in Indonesia. One of the manifestations of allergies is allergic rhinitis. Many factors can trigger the recurrence of rhinitis, including exposure to house dust mites. This study aims to identify the population of house dust mites in the classrooms and student residences. This study was participated by 74 FK UNRI students with allergic rhinitis. The samples included dust collected from residences and classrooms consisting of four large classrooms, three small classrooms, four laboratories, two examination rooms, 12 skills lab rooms, and 15 tutorial rooms. Detection of dust was performed using the direct method. The results showed that no classroom (0%) was found with house dust mites. However, there were 37.8% of residences were positive. Based on the result, it can be concluded that the high population of house dust mites in the students’ residences becomes an essential factor as a chronic stressor for allergic rhinitis.

Clinical and laboratory characteristics of tick-borne rickettsiosis related to <i>Rickettsia sibirica</i> and <i>Candidatus Rickettsia tarasevichiae</i>

The Siberian tick-borne typhus (STT) is the most common tick-borne rickettsiosis (TBR) in Russia, registered in 17 administrative territories of the Southern Siberia and the Far East. The aim of this study was to describe clinical picture, pathological data and results of laboratory diagnostics during fatal mixed infection caused by two Rickettsia species most common in Russia — pathogenic Rickettsia sibirica and poorly examined Candidatus R. tarasevichiae, including identification of its etiological agents. A four-year-old girl in Krasnoyarsk Krai in a hyperendemic focus of the Siberian tick-borne typhus after tick sucking revealed typical TBR symptoms (scab at the site of tick suction, fever, spotted rash, myalgia) and meningeal syndrome, which is not typical for the Siberian tick-borne typhus. The child died on the seventh day of illness. Autopsy data (hepatosplenomegaly; cerebral edema, which was the immediate cause of death) and the results of histological examination (productive vasculitis of the brain, spinal cord and skin, polymorphic cell perivascular infiltrates in the liver and lungs, serous meningitis, myeloid hyperplasia of the spleen and lymph nodes, interstitial lymphoid infiltration in the myocardium) confirmed the clinical diagnosis of tick-borne rickettsiosis. The patient’s blood and brain samples were tested for a wide range of tick-borne pathogens and enteric viruses that cause brain damage using PCR followed by sequencing of the positive samples. The DNA of Rickettsia sibirica and Candidatus Rickettsia tarasevichiae was found in both blood and brain samples. R. sibirica was identified by the nucleotide sequences of gene fragments gltA, ompA and ompB, and Candidatus R. tarasevichiae — by the gltA and ompB genes using nested PCR and sequencing. All amplified fragments were sequenced in both directions; the obtained sequences were deposited in the GenBank database under the inventory numbers MK048467–MK048475. We have not identified other tick-borne pathogens or intestinal viruses in the patient samples able to result in meningeal syndrome. The area where the child was sucked by the tick belongs to the regions with a high incidence of STT. Several species of mites coexist in this area; of these, Haemaphisalis concinna, the carrier of R. sibirica, dominates the populations of Ixodes mites, while Ixodes persulcatus, the main reservoir of Candidatus R. tarasevichiae, is less common. As a result of the conducted studies, for the first time in the Russian Federation, a verified case of a lethal infection associated with two species of Rickettsia — Rickettsia sibirica and Candidatus R. tarasevichiae — was identified and described.

Incidence of various insect pests and their seasonal history on chilli crop in Malwa region

The experiment entitled Incidence of various insect pests and their seasonal History on chilli crop in Malva region of Madhya Pradesh conducted during Rabi 2018-2019 and 2019 -2020 in the department of Entomology of School of agriculture at Dr. B.R. Ambedkar University of social science Mhow Indore (M.P.). during the year of 2018 - 2019 & 2019 - 2020, the data on thrips and mites population and per cent white fly, jassids and aphids infestation under field condition along with weather parameters viz., temperature (Maximum and minimum), relative humidity and rainfall are given in Observations recorded on thrips population revealed that activity of thrips started from second week of July (21SW) and continued up to the crop termination i.e. last second week of December. The maximum thrips population (6.77) was recorded. The observation recorded on mites population revealed that activity of mites started from second week of July (21 SW) and continued up to the crop termination i.e. last second week of December. The maximum mites population (5.45) was recorded. The maximum whitefly population (5.22) was recorded in 3rd week of August (25 SW) when maximum and minimum temperature and humidity respectively. The maximum aphid population (4.53) was recorded in 3rd week of August (26 SW) when maximum and minimum temperature and humidity respectively. The maximum jassid population (3.87) was recorded in 3rd week of August (38 SW) when maximum and minimum temperature and humidity respectively. The leaf curl infestation of 9.2 per cent was first observed in third week of July (21 SW), which increased gradually and reached a maximum of 23.00 per cent in the 8th week after transplanting during 28th SW, when the maximum and minimum temperature and relative humidity were recorded respectively.

Unwelcome guests at farms breeding the black soldier fly,Hermetia illucens (L.) (Diptera Stratiomyidae)

Livestock farms represent a source of attraction for other species, which find food resources on the animals themselves, in the food supplied to them, in their manure, etc. Insect farms too can suffer infestation by different organisms living on substrates or behaving as parasites and/or predators. Breeding of the black soldier fly (BSF),Hermetia illucens (L.) requires organic materials which are attractive for other arthropods (commensals, mycetophages, scavengers, etc.). During recent years, the breeding system adopted at the Di.Pro.Ve.S. of the Università Cattolica del Sacro Cuore, Piacenza (Italy), has suffered the presence of the following ‘pests’:Megaselia scalaris (Loew) (Diptera Phoridae),Muscina stabulans (Fallén) (Diptera Muscidae),Monomorium pharaonis (L.) (Hymenoptera Formicidae) andCaloglyphus berlesei (Michael) (Astigmata Acaridae). The use of fermented fruit, vegetables or of an artificial diet to induce egg laying proved to be attractive for small flies such asM. scalaris. This species also takes advantage of the aqueous sugar solution used to feed BSF adults. Infestations byM. scalaris are worrying because its larvae can compete efficiently with those of the BSF in substrate colonisation. Likewise,M. stabulans can be attracted by the substrates, even though this species has not shown the same levels of high competitiveness as the previously mentioned species.M. pharaonis was observed to prey on eggs and newborn BSF larvae. Lastly, infestations by the miteC. berlesei were detected when conditions for the larval development of the BSF were not optimal. This species could also be harmful for the workers involved in the breeding. The establishment of insect and mite populations inside BSF rearing boxes suggests that a careful analysis should be made based on the location of the breeding facility and a series of measures should of course be adopted when this kind of structure and activities are designed and realised.

Strip spraying delays pyrethroid resistance in the redlegged earth mite, Halotydeus destructor: a novel refuge strategy.

Pesticide resistance has seen control options for the redlegged earth mite (RLEM), Halotydeus destructor, dwindle for Australian grain farmers. The recent discovery of high recessiveness for pyrethroid resistance in RLEM provided an opportunity to examine the feasibility of a refuge strategy to slow the evolution of resistance. Unlike lepidopterous pests in Bt crops, where refuge strategies are routinely practiced, RLEM is a slow-moving pest, which will impact the design of susceptible refuges. Firstly, we confirmed the pyrethroid resistant allele is recessive to the susceptible (wildtype) allele (in terms of resistance) across spatially separated Australian populations. Secondly, we demonstrated that a small, localized resistant mite population can revert to susceptibility at field relevant scales and conditions. Next, we used a simulation modelling approach to design a practical refuge strategy to maintain susceptibility to pyrethroids in populations with a low incidence of resistance. Certain configurations (e.g. a pesticide strip width of 50 m and refuge spacing of 10m) maintained low levels of resistance across a 10-year time horizon, with lower mite abundance and minimal yield loss. A larger refuge proportion did not always delay resistance, and, under certain conditions, increased resistance frequency. Strip spraying to maintain refuges can be readily incorporated into RLEM management programs where sprayer widths in commercial cropping contexts are typically between 20-40 m. A refuge approach to RLEM management that uses strip spraying may enhance long term control options in the absence of new chemical registrations but will now require field validation. © 2021 Society of Chemical Industry.

Evaluation of in-house factors affecting the population distribution of Dermanyssus gallinae in cage and backyard rearing systems by using a modified monitoring method.

Dermanyssus gallinae (poultry red mite, PRM) is a main ectoparasite of poultry that represents a serious economic threat to all farming systems, including cages and backyard flocks. In recent years, economic losses associated with this ectoparasite have progressively increased, mainly because of the lack of information regarding its population dynamics and appropriate control methods. In this study, we used a modified monitoring method to examine the in-house factors affecting the population density of D. gallinae. PRMs have been found in all poultry houses examined in Turkey. The largest population was detected in the front and back parts of the middle rows in cage systems as well as in perches in backyard systems. Relative humidity, light, and temperature might be the most affecting factors on the mite distribution inside the poultry houses. Besides, the mite populations are influenced mainly by the last (chemical) treatment date and the construction materials of the building. Dermanyssus gallinae were found to be the most dominant mite species (98.9%), followed by Cheyletus sp. (Cheyletidae); also some Acaridae (Tyrophagus spp.) and Oribatida were identified. Hence, further research on Cheyletus sp. is required to elucidate their predatory potential and develop future control strategies. This study contributes to understanding the PRM population behavior in poultry houses as well as their monitoring and control methods, which are key components in the appropriate application of integrated pest management programs.

No influence on population dynamics of spider mites in cotton fields of intercropping with walnut, a poor-quality host

Intercropping is a common agricultural practice used to improve crop yields and profits; however, the intercrop species and its quality as a host for the main crop's key pests can affect the pests' population dynamics under intercropping conditions. Fruit trees - cotton intercropping systems are commonly applied in Xinjiang of China, and previous studies have confirmed that intercropping of cotton with species (e.g., jujube and apple) that are good spider mite hosts can increase the spider mite density in cotton. In this study, the effect of intercropping cotton with walnut, which is a poor host for the key spider mite pest Tetranychus truncatus, was examined. For this spider mite, feeding on walnut leads to significantly longer development time for larvae + nymphs and a short oviposition period which leads to a lower total fecundity, lower survival rate and lower intrinsic growth rate (rm) compared to cotton. Correspondingly, in the two-year, multiple-scale field study, we found that the population dynamics of spider mites in cotton did not significantly differ in the field plots between a walnut-cotton intercropping system and monocultural cotton. Similar trends of spider mite density were also observed in commercial fields. Based on previous work and the current study on fruit tree-cotton intercropping systems, we concluded that while intercropping cotton with intercrop species that are suitable spider mite hosts increase the spider mite population in intercropped cotton, the use of a poor host plant such as walnut has no significant effect on spider mites populations in cotton. Hence, our study results improved the understanding of pest management and monitoring in intercropped cotton systems.