Mite Levels Research Articles

Evaluation of a Varroa-resistant Apis mellifera selected stock under a commercial beekeeping system in Northern Argentina

The selection and breeding of Apis mellifera colonies with a natural ability to survive Varroa destructor provide a long-term solution for a sustainable apiculture. In Argentina, a selected honey bee stock showing resistance to the mite (named R stock) has been identified and characterized under laboratory and field conditions. Currently, this selected material is being preserved for further evaluations in a commercial beekeeping system. In this study, we analyzed the population strength, mite levels and honey production of the R stock during two consecutive beekeeping seasons (a total of 16 surveyed apiaries). Results indicated low levels of adult bee mite infestation in R colonies from all apiaries (mean for both seasons: 0.3 ± 0.5% in spring; 1.5 ± 2.0% in summer). The colony strength and food stores of R colonies were similar between apiaries and seasons, and the honey yield per apiary ranged within the average production registered in commercial apiaries of the region. During each following autumn, a subgroup of R colonies was used to compare colony strength, food stores and mite infestation level with non-selected mite-susceptible colonies (named S stock). Overall, R colonies exhibited lower worker brood population, higher honey stores and lower levels of Varroa infestation in autumn compared to S colonies. Our results indicate that R stock displayed a significant potential to maintain the mite resistance phenotype under a commercial beekeeping system, better regulates its overwintering conditions, and exhibits a commercially adequate honey production. Present results provide tools for improving environment-friendly strategies to control varroosis in productive honey bee colonies.

Effect of Different Fertilization Strategies on Infestation of Brown Wheat Mite and Wheat Productivity

The brown wheat mite, Petrobia tritici, poses a significant threat to wheat fields. While fertilizers can increase crop productivity, imbalanced application may exacerbate plant susceptibility to pests. This study aimed to evaluate the impact of various NPK fertilization programs on P. tritici infestations over two consecutive cropping seasons. The results revealed significant differences in mite infestation among the treatment groups (p < 0.001). The lowest populations (1.1 and 3.0 mites/leaf) were observed in the treatments sprayed with phosphoric acid (at 0.75 and 1.00 cm/L), where the infestation appeared approximately 120 days after sowing; in contrast, it appeared early at 75 days in the other treatments. Conversely, treatments lacking potassium fertilizer presented the greatest degree of mite injury levels (49.5–57.7 mites/leaf). Although these treatments provided moderate leaf nutrition and crop yield, the highest nutritional content and total yield (10.49 and 9.71 1 t/ha for the two years) were observed in the treatment that received 224:70:100 kg fad−1 commercial fertilizers (=178:25:114 kg ha−1 NPK units) as soil fertilization, which was followed by the treatment with a foliar application of phosphoric acid (1.00 cm/L) with a total yield of 9.34 and 8.53 1 t/ha for the two years. In this treatment, the P. tritici density was moderately high at 9.40 and 6.32 mites/leaf over the two years, respectively. The consistency of P. tritici density and total yield ranking across both years indicated reliable estimates of the impact of fertilization. This study suggests that potassium sulfate application is crucial for reducing P. tritici density and that foliar phosphoric acid application instead of soil application reduces the number of P. tritici and delays its occurrence.

Resistance to Varroa destructor is a trait mainly transmitted by the queen and not via worker learning

How beekeepers can propagate the Varroa-resistant traits they have in their colonies depends on how varroa resistance, i.e. the key hygienic behavioural traits, is passed onto the next generation. This study investigates if the key hygienic traits are passed between workers via learning as is known to happen in bumble bees, or are the resistant traits encoded into the queens and thus her offspring. To test this, we re-queened known mite-resistant colonies with mite-naïve (susceptible) queens in both Hawaii and the UK. We also placed resistant queens in susceptible colonies in the UK. After 5 months in Hawaii and 12 months in the UK, mite levels in adults and brood were measured. In Hawaii, mite removal and cell recapping levels were also assessed. In both locations, the mite levels in colonies headed by suspectable (mite-naïve) queens or their daughters significantly exceeded that found in colonies headed by resistant queens or their daughters. The initial presence of resistant or suspectable workers did not affect the result. Therefore, to propagate mite-resistant traits, beekeepers only need to re-queen a colony with a locally mated queen from an established resistant population, as some UK and Hawaiian beekeepers are already doing.

Varroa destructor economic injury levels and pathogens associated with colony losses in Western Canada

IntroductionThe honey bee parasitic mite, Varroa destructor, is considered the main factor associated with winter colony losses. To control this mite, beekeepers must implement Integrated Pest Management (IPM) strategies. An effective IPM strategy is based on timely monitoring of mite levels to treat the colonies when the mites reach an economic threshold and before they grow to damaging levels (economic injury level). Additionally, concerns have been raised about the possible interaction between V. destructor and other stressors; stressors acting additively or synergistically may lead to high colony mortality.MethodologyVarroa destructor levels were recorded in colonies from five regions of British Columbia, Canada: Lower Mainland, Kootenay, Okanagan, Cariboo, and Peace. Mite levels were analyzed for associations with colony strength and mortality, as well as with other pathogens that were identified using total RNA sequencing.ResultsThe Kootenay and Lower Mainland regions had the highest V. destructor levels in the fall (3.38±0.65 and 2.51±0.57, respectively) followed by the Okanagan (1.54±0.36), Cariboo (1.31±0.39), and Peace (0.66±0.25) regions. The Peace region had a significantly lower proportion of dead colonies than the other regions. Varroa destructor levels in the fall significantly predicted odds of colony mortality in the spring. Colonies with ≥ 1% mite infestation in the fall (August) had a significantly higher mortality rate (p=0.005) compared to colonies with <1% mite levels. Therefore, treatment is recommended above that threshold. Also, deformed wing virus-B levels were 8.4 times higher than those of deformed wing virus-A variant in all the regions and were highest in the Kootenay region, which also had the highest rate of colony losses. Lastly, Malpighamoeba mellificae and Nosema (Vairimorpha) apis transcripts were identified along with other pathogens that deserve further investigation, including Apis mellifera filamentous virus, Apis rhabdovirus, Lake Sinai virus, Varroa tymo-like, and Apis mellifera solinvivirus 1.DiscussionThe dynamic nature of host-pathogen interactions requires frequent pathogen surveillance to determine the prevalence and levels of parasitic mites and associated infectious diseases, and their impact on honey bee health, not only in the regions of this study, but globally. Nevertheless, more studies are needed to determine the nature of the type of interaction between the identified pathogens and V. destructor. Also, more research is needed to evaluate their potential impact on colony survival, to provide accurate mite and disease control recommendations to beekeepers.

Effects of common co-occurring pesticides (a neonicotinoid and fungicide) on honey bee colony health in a semi-field study

Multiple stressors are linked to declines of insects and important pollinators, such as bees. Recently, interactive effects of multiple agrochemicals on bees have been highlighted, including fungicides, which increase toxicity of neonicotinoid insecticides. Here, we use a semi-field study across two seasons in controlled foraging tunnels to test the effects of a field application of a commercial fungicide product with two active ingredients (pyraclostrobin and metconazole) applied at label rates. We also examine its interactive effects with the neonicotinoid insecticide clothianidin, at a conservative field-realistic dose of 2.23 ppb, on 48 honey bee colonies. We found combined effects of pesticide exposure, including additive 2.93-fold increases in mortality, and an additional effect of increased infestation levels of the ectoparasitic mite, Varroa destructor. Pesticide treatments also reduced colony activity, reduced colony weight, and increased sugar consumption of whole colonies. These findings indicate that typical sublethal exposure levels to common, co-occurring agrochemicals in the field significantly affect the health of whole honey bee colonies, highlighting an unintended consequence of increasing pesticide applications.

Assessing Panonychus ulmi (Acari: Tetranychidae) Infestations and Their Key Predators on Malus domestica Borkh in Varied Ecological Settings

This study investigates the infestation dynamics of Panonychus ulmi McGregor 1916 and its associated predators in Malus domestica borkh orchards across three towns in Morocco: Midelt, Ait Sebaa, and Imouzzer-Kender, situated in the Fez-Meknes and Draa-Tafilalt regions. Ait Sebaa (Fez-Meknes region), characterized by high temperatures and a lower altitude, exhibited a substantial increase in P. ulmi and its predators. In contrast, Midelt (Draa-Tafilalt region), with the highest altitude, demonstrated lower mite counts. Imouzzer-Kender (Fez-Meknes region), at an intermediate altitude, showed moderate mite levels. Detailed findings reveal a positive correlation between P. ulmi and temperature, as well as with phytoseiid mites. Conversely, a negative correlation exists between P. ulmi and altitude. Additionally, a positive correlation between phytoseiid mites and temperature is identified. Overall, this study provides valuable information on the ecological interactions between mites, temperature, altitude and humidity in distinct Moroccan regions, highlighting the need to take regional specificities into account in pest management strategies.

Mite allergen sensitization patterns in Turkish children: Age-related changes and molecular correlations.

Mites are ubiquitous aeroallergens found worldwide. Elucidating individual mite allergen sensitization patterns provides critical insights for managing allergic diseases. This study aimed to investigate molecular allergen (MA) sensitization patterns across different age groups and explore cluster relationships among mite-sensitized children. We analyzed 76 children who exhibited sensitization to at least one of the 17 distinct mite MAs through microarray testing. Dermatophagoides farinae exhibited a slightly higher prevalence of sensitization compared with Dermatophagoides pteronyssinus. Der p 1/2 and Der f 1/2 demonstrated an almost 40% sensitization rate, while Der p 10/Blo t 10, Der p 20, Der p 23, and Gly d 2/Lep d 2 displayed an approximately 20% sensitization rate. Sensitization levels and ratios increased significantly with age for Der p 23 but showed numerical rises for other MAs, except for Der p 10/Blo t 10. The presence of various types of atopic diseases had only a minimal impact on sensitization profiles. Strong correlations emerged between Der f 2 and Der p 2, Der p 10 and Blo t 10, Der p 21 and Blo t 5, as well as Gly d 2 and Lep d 2. Hierarchical cluster analysis substantiated these relationships. Der p 10 and its homolog Blo t 10-sensitive patients (15/76) were mostly seen as mono sensitization(12/15). Ten patients exhibited monosensitization to Der p 20, suggesting a possible association with scabies infection. In children, mite sensitization diversity and levels increased with age. The presence of significant correlations/cluster relationships among these sensitizations underscores homologies among specific MAs.

Assessment of Efficacy of Algerian Propolis against the Parasitic Mite Varroa destructor and Safety for Honey Bees by Spray Treatment.

Varroa destructor is an ectoparasitic mite and is considered one of the most important causes of honey bee population loss. In the last years, substances of botanical origin have emerged as natural alternatives to diminish the mite population levels. Propolis is a natural product and is used by honey bees for multiple tasks, including protection from pathogens and parasites, and varroacidal activity of propolis extracts has been shown. In this study, we investigated the potential of propolis, collected by native Algerian honey bee subspecies (Apis mellifera intermissa and A. m. sahariensis) in different locations in Algeria and extracted by ultrasound, to control mites of V. destructor and tested the safety for the honey bees. The most important results were that the best propolis extracts at 10% killed 100% of the Varroa mites within 3-4 h in a Petri dish assay. In addition, when we sprayed A. m. intermissa bees infested with Varroa mites with a 10% concentration in a mini-hive setup, we scored a high mite mortality of 85-87% with the best propolis extracts, and importantly, there was no mortality in the bees. Our data demonstrated that propolis extracts in Algeria could be used in honey bee colonies by spraying against Varroa mite infestations, which may develop as an easy method for local beekeepers to control Varroa in their hives. Further research should investigate the mechanism of action.

The Varroa paradox: infestation levels and hygienic behavior in feral scutellata-hybrid and managed Apis mellifera ligustica honey bees

The Varroa destructor mite is a parasitic threat to managed and feral honey bee colonies around the world. Beekeepers use miticides to eliminate Varroa in commercial hives, but these chemicals can diminish bee health and increase miticide resistance. In contrast, feral honey bees have developed multiple ways to counteract mites without chemical treatment. We compared mite levels, grooming habits, and mite-biting behavior between feral Africanized honey bees (genomically verified Apis mellifera scutellata hybrids) and managed Italian honey bees (A. mellifera ligustica). Surprisingly, there was no difference in mite infestation levels between scutellata-hybrids and managed bees over one year despite the regular use of miticides in managed colonies. We also found no differences in the social immunity responses of the two groups, as measured by their hygienic habits (through worker brood pin-kill assays), self-grooming, and mite-biting behavior. However, we provide the first report that both scutellata-hybrids and managed honey bees bite off mite chemosensory forelegs, which the mites use to locate brood cells for reproduction, to a significantly greater degree than other legs (a twofold greater reduction in foreleg length relative to the most anterior legs). Such biting may impair mite reproduction.

Hay diseases in Iceland

Diseases due to work in hay dust have long been known in Iceland and the first written records of them appear in the beginning of the 17th century. At the end of the 18th century, a district doctor alleges that they cause many deaths in the country. In the latter part of the 20th century, research was started to investigate the causes and nature of hay diseases in Iceland. Studies of allergens showed high levels of storage mites in hay. Highest levels were of Tarsonemus sp., Acarus farris and Lepidoglyphus destructor. A several micro-fungi were also found, most commonly Rhizopus sp., Penicillium sp. and Aspergillus sp. Micropolyspora faeni was also found in all hay samples. A study was done on people aged 6-50 years in two districts in Iceland. In one district farmers used almost exclusively dry hay and in the other they used 80-90% silage. There was no difference in IgE-mediated allergy between the provinces, but most had positive skin tests for L. destructor and cattle. Those with symptoms connected with hay dust most often reported nasal symptoms (79%), eye symptoms (63%), cough (41%), dyspnea (32%) and fever (21%). Those who had positive skin reaction complained most often of nose and eye symptoms. A study was also conducted on subjects aged 16-87 years from the same regions investigating precipitin tests for M. faeni, Thermoactinomyces vulgaris and Aspergillus fumigatus. Pulmonary symptoms and lung function were also investigated. Precipitin tests were almost exclusively positive for M. faeni, and 5 individuals were positive for A. fumigatus and none for T. vulgaris. The precipitin tests were significantly more often positive in those working almost exclusively with dry hay (72.9% vs. 23.9%). They had also more commonly obstructive pulmonary disease (FEV1/FVC%<70: 24.8% vs. 9.5%) as well as dyspnea when walking on level ground. There was a positive correlation between positive precipitin tests for M. faeni and dyspnea walking on level ground. The sensitivity and specificity of positive precipitin tests for M. faeni were investigated to detect farmer’s lung. The sensitivity was 82% and specificity was only 49%. A survey of emphysema in patients in the only Pulmonary Clinic in the country showed that farmers had more often emphysema than the rest of the country population, and 58% of farmers with emphysema had smoked compared to 94% of other emphysema patients.

Efficacy and trade-offs of an innovative hyperthermia device to control Varroa destructor in honeybee colonies

For decades, the honeybee, Apis mellifera, has suffered from severe colony losses due to the ectoparasitic mite Varroa destructor. Various strategies based on chemicals fail to adequately control varroa mite populations, and often comprise side-effects on the host, parasite resistance and residues in hive products. Reduced temperature tolerance of V. destructor compared to its host has long been recognised and accordingly, the potential of hyperthermia to disrupt mite reproduction within honeybee brood cells or even kill adult parasites. Yet, earlier studies on hyperthermia remain largely anecdotal, and readily implementable solutions have so far been lacking. This study investigates autonomously controlled interval heating from within brood combs throughout the season compared to control colonies maintained according to good apicultural practice. We documented treatment-dependent colony growth dynamics and honey production at three apiaries, complemented by regular monitoring of varroa mite levels and comprehensive digital assessments of brood development over time. Our one-year field trial suggests the evaluated hyperthermia device efficiently suppresses mite populations below critical thresholds until autumn. Whilst a general winter reference-curing revealed similar mite infestations of colonies previously treated with hyperthermia versus formic acid (control), only the latter imposed substantial overwintering burdens indirectly through frequent late-season queen supersedure. However, relative to targeted pupae, increased mortality particularly of heat-treated non-target brood stages (eggs and larvae) appeared to trigger compensatory colony-level responses, translating into temporarily decreased numbers of adult workers coupled with increased pollen foraging and overall lower honey harvests. Valuable insights into previously unrecognised side-effects of hyperthermia and mitigation thereof may ultimately permit successful routine applications of this chemical-free approach to combat the major threat to honeybees worldwide.

Soil oribatid mite community structure and its relationship with environmental factors in different agricultural land-use types in Shibing Karst

The karst world natural heritage site is characterized by fragility due to severe rocky desertification. Buffer zone functions as the ecological barrier of the core area of the heritage site, and can play an ecological filtering role in the core area. Therefore, buffer zones are of great ecological significance. In order to reveal the community characteristics of soil oribatid mites in different agricultural land-use in the buffer zone of Shibing Karst World Natural Heritage and their relationship with environmental factors, soil oribatid mites in the buffer zone of corn field (CF), golden pear garden (GP) and tobacco field (TF) were collected in September 2021. A total of 1220 oribatid mites belonging to 79 genera and 41 families were found in the study. Our key results include (1) The family number, genus number, individual number, and individual density of GP are higher (2) Scheloribates is the dominant group, 22 genera such as Oppiella, Tectocepheus, and Xylobates are common groups, and 56 genera such as Neoribates and Protoribates are rare groups. (3) The Diversity index of GP is higher than that of other cultivated land types. Community similarity analysis shows that the similarity between GP and CF is high, but all habitats are at a medium level of dissimilarity. (4) Analysis of the ecological group of oribatid mites shows that Poronota is more abundant than Macropylina and Gymnonota. (5) The Diversity index, richness index, family and genus level of oribatid mites were significantly positively correlated with soil humidity (SH) and the number of genera, individuals and individual density were significantly positively correlated with total phosphorus (TP). Redundancy analysis indicates that total phosphorus (TP), total potassium (TK), and soil organic matter (SOM) are the main environmental factors affecting the distribution of soil oribatid mites communities. Based on the above research results, it can be seen that there are differences in the community structure of soil oribatid mites in different agricultural land-use in the study area. The use of dominant genera of mites can preliminarily indicate the soil ecological environment of different agricultural land-use. The research results provide basic data for the biodiversity protection of soil animals in different agricultural land-use in the buffer zone of Shibing Karst World Natural Heritage.

Cold storage as part of a Varroa management strategy: effects on honey bee colony performance, mite levels and stress biomarkers

Placing honey bee colonies in cold storage has been proposed as a way to induce a pause in brood production as part of a Varroa mite treatment plan. Here, we exposed colonies to combinations of with or without an October cold storage period and with or without a subsequent miticide application. We then measured the effects of those treatments on colony-level variables (i.e. colony size, Varroa infestation level, survivorship and hive weight and temperature) and pooled individual-level variables that are associated with nutritional and stress responses. Colonies were assessed before and after cold storage, and again post winter, for a total duration of about 5 months, and the experiment was repeated. Brood levels were significantly lower after cold storage, and hive temperatures indicated that most or all brood had emerged after about two weeks in cold storage. However, Varroa levels at the end of the experiments in February were not significantly different among treatment groups. Colonies kept outside (not subjected to cold storage) and treated with a miticide had higher survivorship on average than any other treatment group, but no other group comparisons were significant, and long-term impact of cold storage on adult bee populations and on colony thermoregulation was low. The bee forage environment was also very different between the 2 years of the study, as rainfall and bee forage availability were much higher the second year. Colonies were over 2.5 times larger on average the second year compared to the first, both in terms of adult bee mass and brood area, and expression levels of nutrition and stress response genes were also significantly higher the second year. The results indicate that limited cold storage would likely have little long-term impact on most colony and individual measures of health, but for such a strategy to succeed levels of stressors, such as Varroa, may also need to be low.

Comparison of indoor (refrigerated) versus outdoor winter storage of commercial honey bee, Apis mellifera (Hymenoptera: Apidae), colonies in the Western United States.

Honey bees (Apis mellifera L.) are critical to the pollination of many important crops in the United States, and one crop that demands large numbers of colonies early each year is almonds. To provide adequate numbers of colonies for almond pollination, many beekeepers move colonies of bees to high-density holding yards in California in late fall, where the bees can fly and forage, but little natural pollen and nectar is available. In recent years, high colony losses have occurred in some operations following this management strategy, and alternative approaches, including indoor storage of colonies, have become more commonly used. The current study evaluated colonies kept indoors (refrigerated and/or controlled atmosphere) for the winter compared with those kept outdoors in either Washington or California. Colonies were evaluated for strength (frames of bees), brood area, lipid composition of worker bees, colony weight and survival, parasitic mites (Varroa mites, tracheal mites), and pathogens (Nosema spp.). No differences were found in colony weight, survival, parasitic mite levels, or pathogen prevalence among the treatments. Colonies stored indoors and outdoors in WA had significantly more frames of bees and less brood present after the storage period than colonies stored outdoors in CA. Lipid composition of honey bees stored indoors was significantly higher than colonies stored outdoors in WA or CA. The implications of these findings for overall colony health and improved pollination activity are discussed.

Dietary aflatoxin B1 induces abnormal deposition of melanin in the corium layer of the chicken shank possibly via promoting the expression of melanin synthesis-related genes

San-Huang chicken is a high-quality breed in China with yellow feather, claw and break. However, the abnormal phenomenon of the yellow shank turning into green shank of San-Huang chicken has been a concern, as it seriously reduces the carcass quality and economic benefit of yellow-feathered broilers. In this study, the cause of this abnormal green skin in shank was systematically investigated. Physiological anatomy revealed that the abnormal skin in shank was primarily due to the deposition of melanin under the dermis. After analyzing multiple potential causes such as heredity (pedigree and genetic markers), environment (water quality monitoring) and feed composition (mycotoxin detection), excessive aflatoxin B1 (AFB1) in feed was screened, accompanied with a higher L-dihydroxy-phenylalanine (L-DOPA) (P<0.05) and melanin content (P<0.01). So it was speculated that excessive AFB1 might be the main cause of abnormal green skin in shank. Subsequently, the further results showed that a high concentration of AFB1 (>170 μg kg–1) indeed induced the abnormal green skin in shank compared to the normal AFB1 content (<10 μg kg–1), and the mRNA levels of TYR, TYRP1, MITE, MC1R and EDN3 genes related to melanin deposition would significantly up-regulate (P<0.01) and the content and activity of tyrosinase (TyR) significantly increased (P<0.05). At the same time, the content of L-DOPA and melanin deposition also increased significantly (P<0.01), which also confirmed the effect of excessive AFB1 on melanin deposition in skin of shank. Results of additional experiments revealed that the AFB1’s negative effect on melanin deposition in skin of shank could last for a longer time. Taken together, the results of this study explained the occurrence and possible mechanisms of the abnormal AFB1-related green skin in shank of chickens. Excessive AFB1 in diets increased the L-DOPA content and melanin abnormal deposition in the chicken shank possibly via promoting TyR content and activity, and the expression of melanin synthesis-related genes. Furthermore, our findings once again raised the alarm of the danger of AFB1 in the broiler production.

All together now: Geographically coordinated miticide treatment benefits honey bee health.

Deformed wing virus (DWV) is a pathogenic virus of honey bees transmitted by the ectoparasitic mite Varroa destructor. Annual overwintering colony losses, accounting for ~25% of all colonies, are associated with high levels of Varroa-DWV infestation. Effective miticide treatments are available to control Varroa. However, the absence of coordinated treatment means environmental transmission of mites continues unchecked. We aimed to determine whether rational, coordinated treatment is beneficial, and characterized the DWV population as an indicator of colony health.This study uses coordinated treatment of Varroa in a geographically isolated environment (Isle of Arran, Scotland) over 3 years. The study area contained 50-84 colonies managed by ~20 amateur beekeepers. Sampling and virus analysis to assess strain diversity and viral loads were conducted before and after treatments, and changes in population diversity were quantified by sequence analysis.Over the 3 years analysis of the virus population revealed that the dominant DWV variant shifted from Type A to Type B in all apiaries, regardless of mite levels or proximity to other colonies. During this period the number of managed colonies increased by 47% (57-84 colonies), but despite this, we estimate total mite numbers decreased by 58%. Synthesis and applications. In this study, the beekeepers in Arran significantly improved the number of colonies they managed, without importing any bees onto the island, indicating that an improved focus on management techniques, through the combination of a coordinated miticide programme and an improved understanding of bee diseases, could yield positive results for bee health and sustainability.

Indoor exposure assessment for levels of dust mite and total volatile organic compounds (TVOCs) in living houses

ABSTRACT The purpose of this study is to measure the levels of dust mites (Dermatophagoides farina group 1 [Der f1] and Dermatophagoides pteronyssinus group 1 [Der p1]) and total volatile organic compounds (TVOCs) in the resident environments with living conditions such as the number of ventilation; the number of window, floor, and temperature; and relative humidity (RH) from vulnerable class in South Korea. Information on residents is designed to be prepared by residents on their general characteristics (daily residence time, heating and cooking type, and cleaning on the day of sampling). Dust mites levels ranged from 24.0 to 1087.5 ng/g with a mean of 215.4 ng/g for Der f1 and from 0.6 to 489.9 ng/g with a mean of 489.9 ng/g for Der p1. Total TVOC levels ranged from 15.3 to 1642.1 μg/m3 with a mean of 219.7 μg/m3. The correlation analysis showed a positive association between Der f1 levels and xylene levels in fall (r = 0.49, r < 0.05) of this study.

Development and assessment of an epidemiologic dashboard for surveillance of Varroa destructor in Ontario apiaries

Varroosis (caused by the Varroa destructor mite) is a key health issue for honey bees in North America. Because these mites can exist in reservoirs of feral honey bee colonies, eradication is impossible, and instead efforts are made to maintain mites below a critical threshold. Monitoring for Varroa mites within a population is key for allocating resources and targeting interventions but surveillance can be difficult and/or expensive. This project aims to reflect on the success of data dashboards developed throughout the 2019-coronavirus pandemic and showcase how these methods can improve surveillance of Varroa mite infestations in Ontario, Canada. Dashboards provide a consistent source of information and epidemiologic metrics through data visualizations, and mobilize data otherwise bound to tables and intermittent reports. In the present work, an interactive dashboard for the surveillance of Varroa mite infestations across the province is proposed. This dashboard was developed using routine ministry inspection data to depict the spatio-temporal distribution of mites across a five-year data collection period. Through interactive figures and plots, able to be disaggregated to a specific region and time frame, this dashboard will allow for members of the beekeeping community to monitor provincial mite levels throughout the season. Seven criteria found to be common across highly actionable COVID-19 dashboards were used in a beta testing stage of development to assess the quality of the dashboard, and critically reflect on its strengths and weaknesses. Furthermore, future directions for surveillance dashboards are explored, including integration with citizen science data collection to develop a comprehensive province-wide surveillance system. The outcome of this project is a functional dashboard proof-of-concept for population-level monitoring of Varroa mites and a model for future tools designed for other species and diseases.

Composition and abundance level of pest mites in jasmine gambier (Jasminum officinale) plantation of Purbalingga, Central Java, Indonesia affected by some abiotic factors

Abstract. Budianto BH, Sasongko ND. 2022. Composition and abundance level of pest mites in jasmine gambier (Jasminum officinale) plantation of Purbalingga, Central Java, Indonesia affected by some abiotic factors. Biodiversitas 23: 5227-5232. The decline in productivity of gambier jasmine flowers is not only caused by the reduction of gambier jasmine land area but also insect, caterpillar and pest mite attacks. Types of pest mites and their population dynamics are closely related to abiotic factor conditions such as temperature, humidity, rainfall, season, an abundance of predatory mites and types of plant cultivars. The study aimed to determine the types of pest mites and some abiotic factors that affect their abundance in gambier jasmine plants. The research method was a survey with a purposive sampling technique. Sampling locations were in Cipawon village, Bukateja sub-district, Purbalingga district, and Central Java Province, Indonesia. The obtained data were analyzed by analysis of variance at an error rate of 0.05. The types of pest mites that were identified consisted of 8 species, namely Brevipalpus phoenicis, B. californicus, B. papayensis, B. obovatus, Tetranychus urticae, T. kanzawai, T. cinnabarinus and Tyrophagus putrescentiae. The type of pest mite always found at each sampling point was B. phoenicis, with an abundance range of 0.027 to 0.067. The results of the analysis of the variance of pest mite abundance in gambier jasmine plantations showed that abundance of individuals between pest mite species did not significantly differ at all sampling points. Based on multivariate analysis, it was noted that trichome density had the most influence on pest mite abundance with a population model of Y = 0.399 + 0.043a + 0.012b.

Localized efficacy of environmental RNAi in Tetranychus urticae

Environmental RNAi has been developed as a tool for reverse genetics studies and is an emerging pest control strategy. The ability of environmental RNAi to efficiently down-regulate the expression of endogenous gene targets assumes efficient uptake of dsRNA and its processing. In addition, its efficiency can be augmented by the systemic spread of RNAi signals. Environmental RNAi is now a well-established tool for the manipulation of gene expression in the chelicerate acari, including the two-spotted spider mite, Tetranychus urticae. Here, we focused on eight single and ubiquitously-expressed genes encoding proteins with essential cellular functions. Application of dsRNAs that specifically target these genes led to whole mite body phenotypes—dark or spotless. These phenotypes were associated with a significant reduction of target gene expression, ranging from 20 to 50%, when assessed at the whole mite level. Histological analysis of mites treated with orally-delivered dsRNAs was used to investigate the spatial range of the effectiveness of environmental RNAi. Although macroscopic changes led to two groups of body phenotypes, silencing of target genes was associated with the distinct cellular phenotypes. We show that regardless of the target gene tested, cells that displayed histological changes were those that are in direct contact with the dsRNA-containing gut lumen, suggesting that the greatest efficiency of the orally-delivered dsRNAs is localized to gut tissues in T. urticae.