How to get rid of the strawberry mite?

Understanding the Strawberry Mite

What is the Strawberry Mite?

Life Cycle of the Strawberry Mite

Understanding the biology of the strawberry mite is essential for effective management. The mite completes its development within a few weeks under favorable conditions, allowing rapid population growth that can damage fruit and foliage.

Egg – Laid on the undersurface of leaves and fruit; incubation lasts 2–4 days at 20 °C.
Larva – Six-legged, actively feeds on plant tissue; stage persists for 3–5 days.
Protonymph – Eight-legged, continues feeding; duration 2–4 days.
Deutonymph – Transitional phase; may disperse to new plants; lasts 1–3 days.
Adult – Fully six-legged, reproduces after 2–3 days; lifespan up to two weeks, during which females lay 30–50 eggs.

Reproduction accelerates when temperature exceeds 18 °C and humidity remains above 60 %. Multiple generations can arise within a single growing season, especially in greenhouse environments.

Overwintering occurs primarily as adults sheltered in leaf litter, soil, or protected plant parts. Survival rates increase with mild winters and abundant debris, providing a reservoir for early-season infestations.

Control measures must target vulnerable stages. Applications of miticides are most effective during the larval and early protonymph periods, typically 3–5 days after egg deposition. Cultural practices such as removing leaf debris and maintaining low humidity reduce overwintering sites and slow population buildup. Timely interventions aligned with the mite’s developmental timeline prevent exponential growth and protect strawberry crops.

Signs of Infestation

Strawberry mite infestations become apparent through specific plant reactions that signal the presence of the pest. Early detection relies on observing alterations in leaf surface texture and coloration, which precede more severe damage.

Fine, silvery webbing on the undersides of leaves and around fruit clusters.
Stippled or mottled foliage, often starting at leaf edges and progressing inward.
Premature leaf drop, especially when accompanied by a dusty appearance.
Small, yellowish to brown specks on fruit that may coalesce into larger lesions.
Reduced vigor and stunted growth, evident by slower canopy expansion and weaker stems.

These indicators provide a reliable framework for confirming an infestation and initiating control measures.

Why is the Strawberry Mite a Problem?

Damage to Strawberry Plants

Strawberry mite infestations manifest as distinct damage to foliage, stems, and fruit. The insects feed on plant sap, causing leaf tissue to turn yellow or bronze and develop a stippled appearance. Feeding sites often become covered with fine silk, creating a webbed layer that reduces photosynthetic efficiency. Young leaves may curl upward or become distorted, limiting the plant’s ability to produce new growth.

The mite’s activity weakens stems, leading to premature wilting and breakage. In severe cases, stems exhibit darkened, necrotic patches that expand outward from feeding zones. Fruit quality deteriorates as mites pierce the surface, leaving small, sunken lesions that enlarge into rot under humid conditions. These lesions reduce marketable yield and may attract secondary fungal pathogens.

Key indicators of mite‑related damage include:

Yellow‑bronze discoloration with a speckled pattern on leaf surfaces
Fine, silken webbing on the undersides of leaves and around growing tips
Curling or distortion of new foliage
Darkened, weakened stem tissue
Small, sunken spots on berries that progress to decay

Early detection of these symptoms enables timely intervention, preventing extensive loss of foliage, vigor, and fruit production.

Impact on Yield

The strawberry mite feeds on young leaves and developing fruit, directly limiting photosynthetic capacity and impairing fruit set. Damage manifests as leaf discoloration, stunted growth, and premature fruit drop, all of which translate into measurable yield reductions.

Typical infestations decrease marketable yield by 15‑30 % in commercial fields. Severe outbreaks can lower total production to less than half of the expected output, with losses proportional to mite density and duration of exposure.

Reduced yield diminishes farm revenue and increases the cost per kilogram of harvested fruit. Lower production also affects supply chains, raising wholesale prices and limiting availability for processing facilities.

Effective control measures restore yield potential:

Timely application of acaricides or biological agents prevents population buildup.
Cultural practices, such as removal of infested foliage and sanitation of planting material, reduce initial inoculum.
Monitoring with sticky traps and regular scouting enables rapid response before damage escalates.

Implementing an integrated management program consistently recovers 80‑95 % of the yield that would otherwise be lost to mite activity, stabilizing production and protecting profitability.

Identification and Early Detection

Visual Inspection Techniques

Examining Leaves and Stems

Inspecting foliage and shoots provides the first reliable indicator of a strawberry mite problem. Damage appears as tiny, pale spots on leaf surfaces, often accompanied by a fine webbing that connects leaves and stems. Mites congregate near the leaf veins, where they feed on cell contents, causing stippling, yellowing, and eventual leaf drop. Stems may show discoloration at the base, with a thin, silvery film indicating mite colonies.

Effective examination follows a systematic routine:

Select several representative plants from each row, focusing on lower and upper canopy levels.
Hold a leaf against bright daylight or a magnifying lamp; look for stippled patches and web threads.
Turn the leaf over to check the underside, where mites are most active.
Examine stem nodes for silvery deposits and any distortion of growth points.
Record the percentage of affected foliage; a threshold of 10 % damaged tissue typically warrants intervention.

Early detection through regular leaf and stem scouting reduces the need for extensive chemical measures and limits spread to neighboring plants. Consistent monitoring, combined with prompt action, forms the foundation of an integrated control strategy for strawberry mite infestations.

Using a Magnifying Glass

A magnifying glass is an essential tool for diagnosing strawberry mite problems early. By examining leaves, stems, and fruit under low magnification, growers can detect the tiny, translucent mites and their characteristic webbing before populations reach damaging levels.

Hold the lens 2–3 cm above the plant surface.
Scan the underside of leaves, focusing on the veins where mites congregate.
Observe for moving specks (mites) and fine silk threads (webs).
Record the number of mites per leaf to assess infestation severity.

Accurate detection allows timely intervention. Once a threshold of 5–10 mites per leaf is confirmed, immediate measures such as targeted acaricide application, introduction of predatory insects, or removal of heavily infested foliage become justified. Re‑inspection with the magnifying glass after treatment verifies efficacy and guides further action.

Symptoms of Mite Activity

Stunted Growth

Strawberry mite infestations frequently manifest as reduced vigor and limited leaf expansion, leading to noticeably stunted growth of the plant. The mite feeds on cell sap, disrupting nutrient transport and causing chlorotic lesions that impair photosynthesis. As a result, seedlings fail to reach expected height, and mature plants produce fewer and smaller fruits.

Effective mitigation requires a combination of cultural, biological, and chemical tactics:

Remove and destroy heavily infested foliage to lower population density.
Introduce predatory mites (e.g., Phytoseiulus persimilis) that target the pest and sustain long‑term control.
Apply horticultural oil or sulfur sprays according to label directions, focusing on the undersides of leaves where mites reside.
Maintain adequate spacing between plants to improve air circulation and reduce humid microclimates favorable to mite development.
Rotate crops and avoid planting strawberries in the same location for more than two consecutive years.

Monitoring should begin early in the growing season. Inspect leaf surfaces with a hand lens every 7–10 days; a population exceeding three mites per leaf warrants immediate intervention. Prompt action halts the progression of stunted growth, restores normal vegetative development, and safeguards fruit yield.

Distorted Leaves

Distorted leaves are a primary visual cue of strawberry mite activity. The mites feed on the undersides of foliage, causing irregular curling, elongation, and a leathery texture that reduces photosynthetic efficiency. In severe infestations, leaves may develop a bronze‑gray sheen and break off prematurely, exposing fruit to secondary pathogens.

Effective management focuses on early detection and targeted interventions. Monitoring should include weekly inspection of leaf margins and the presence of fine webbing. When distortion reaches a threshold of 10 % of foliage, implement the following actions:

Apply a miticide approved for Fragaria spp., following label rates and re‑treatment intervals.
Introduce predatory insects such as Phytoseiulus persimilis to suppress mite populations naturally.
Remove and destroy heavily distorted leaves to lower the local mite load.
Maintain adequate ventilation and avoid excess nitrogen fertilization, which favors mite reproduction.

Consistent application of these measures limits leaf damage, preserves plant vigor, and reduces the overall mite pressure on the strawberry crop.

Effective Control Strategies

Cultural Control Methods

Crop Rotation

Crop rotation interrupts the strawberry mite life cycle by removing the preferred host before the pest can reproduce. When strawberries are replaced with non‑host crops for a full growing season, mite populations decline in the soil and on residual plant debris.

Effective rotation crops include:

Brassicas (e.g., cabbage, broccoli) – poor hosts for the mite, provide high biomass.
Legumes (e.g., beans, peas) – improve soil nitrogen, do not support mite development.
Cereals (e.g., wheat, barley) – create a physical barrier and allow for easy mechanical weed control.
Cover crops such as mustard or buckwheat – suppress weeds and encourage beneficial soil organisms.

The rotation interval should be at least one year, preferably two, to ensure that overwintering stages are eliminated. Soil preparation before re‑planting strawberries should involve thorough removal of crop residues, deep tillage, and, if feasible, a brief period of solarisation to further reduce surviving mites.

Integrating rotation with other cultural practices—such as mulching, sanitation, and the introduction of predatory insects—enhances overall control. By systematically denying the mite a continuous food source, growers achieve long‑term population suppression without reliance on chemical treatments.

Sanitation and Weeding

Effective control of the strawberry mite relies on rigorous sanitation and thorough weeding. Cleanliness removes breeding sites and reduces the population that can infest plants. After each harvest, remove all plant debris, fallen leaves, and fruit remnants. Dispose of the material by burning or deep burial to prevent mite survival. Disinfect tools, containers, and irrigation equipment with a solution of 10 % bleach or a commercial horticultural sanitizer before reuse.

Weeding eliminates alternative hosts and shelters where mites can hide. Identify and eradicate weeds that grow near strawberry beds, especially those belonging to the Chenopodiaceae and Amaranthaceae families, which frequently host the mite. Follow a systematic approach:

Survey the area weekly for emerging weeds.
Pull or cut weeds before they set seed.
Apply a pre‑emergent herbicide approved for strawberries to suppress germination of persistent species.
Mulch with clean, inorganic material to block weed growth and facilitate soil drying, which is unfavorable for mites.

Maintaining a clean, weed‑free environment disrupts the mite life cycle, lowers infestation pressure, and supports the effectiveness of any chemical or biological treatments applied subsequently. Regular implementation of these sanitation and weeding practices forms the foundation of an integrated mite‑management program.

Proper Spacing

Proper spacing between strawberry plants limits the humidity and leaf wetness that favor the strawberry mite. When foliage is evenly distributed, air circulates more freely, reducing the micro‑climate that mites exploit. The physical distance also creates a barrier that slows the insects’ movement from plant to plant.

Plant spacing: 12–18 inches (30–45 cm) between individual crowns.
Row spacing: 3–4 feet (90–120 cm) between rows.
Runner management: prune excess runners to maintain the prescribed distances.
Mulch placement: keep mulch a few centimeters away from the crown to prevent mite shelter.

Implementing these distances begins at planting. Thin seedlings to the recommended 12–18 inch gap, then stake or trellis rows to keep them upright and separated. After establishment, regularly inspect the canopy and remove any overcrowded growth that develops as runners spread.

Consistent adherence to the spacing guidelines reduces mite colonization pressure, simplifies scouting, and enhances the effectiveness of any additional control measures such as biological agents or targeted sprays.

Biological Control Options

Beneficial Insects

Beneficial insects provide natural suppression of the strawberry mite, reducing reliance on chemical treatments. Introducing these predators creates a self‑sustaining population that attacks all life stages of the pest.

Predatory mites such as Phytoseiulus persimilis and Neoseiulus californicus consume mite eggs and larvae. They thrive in humid environments and require a steady supply of prey; supplemental releases during early infestation keep their numbers high.

Lady beetles (Coccinellidae) target adult mites and other soft‑bodied insects. Planting flowering borders with dill, fennel, or yarrow attracts adult beetles and supplies nectar for sustained activity.

Green lacewings (Chrysopidae) prey on mite nymphs. Their larvae, often called “aphid lions,” also feed on spider mites and aphids, offering broader pest control. Providing shallow water sources and avoiding broad‑spectrum insecticides supports lacewing populations.

Predatory thrips (Aeolothrips intermedius) feed on mite eggs and early instars. They prefer warm, dry conditions and can be encouraged by mulching with straw or leaf litter, which supplies shelter.

Hoverflies (Syrphidae) lay eggs on foliage; emerging larvae consume mites and aphids. Planting a mix of buckwheat, coriander, and sweet alyssum supplies adult hoverflies with pollen and nectar.

Implementation checklist

Select species compatible with local climate and garden conditions.
Purchase certified, pesticide‑free insects from reputable suppliers.
Release insects in the early morning or late afternoon to reduce exposure to sunlight.
Monitor pest and predator populations weekly; add supplemental releases if mite numbers rise.
Avoid insecticidal sprays that could harm beneficial insects; use targeted, low‑toxicity options only when necessary.

By maintaining habitat diversity and regularly replenishing predator populations, growers can achieve effective, long‑term control of strawberry mite infestations.

Introducing Predatory Mites

Predatory mites are a biologically based solution for managing the strawberry mite that attacks cultivated berries. These natural enemies locate, capture, and consume the pest at all life stages, reducing population pressure without chemical residues.

Effective species include Phytoseiulus persimilis, Neoseiulus californicus, and Amblyseius swirskii. Each species prefers specific environmental conditions:

P. persimilis: thrives in humid, cool environments; optimal for greenhouse production.
N. californicus: tolerates higher temperatures; suitable for open‑field rows.
A. swirskii: adapts to a wide temperature range; useful when multiple pest species coexist.

Application guidelines:

Release predatory mites when the target pest density reaches 2–3 adults per leaf.
Distribute insects evenly across the canopy, targeting leaf undersides where the pest hides.
Repeat releases every 7–10 days until pest counts fall below economic thresholds.
Maintain humidity above 60 % and avoid broad‑spectrum insecticides that could harm the predators.

Integration with cultural practices enhances efficacy. Remove plant debris that shelters mites, ensure proper irrigation to sustain humidity, and monitor populations weekly with a hand lens or sticky traps. When predator numbers remain stable, pesticide applications can be reduced or eliminated, preserving fruit quality and consumer safety.

Overall, predatory mites provide a sustainable, residue‑free approach to suppressing the strawberry mite, fitting within integrated pest management programs and supporting long‑term orchard health.

Organic and Chemical Treatments

Neem Oil Application

Neem oil, a cold‑pressed extract from the seeds of Azadirachta indica, acts as an insect growth regulator and repellent for strawberry mite populations. Its active compound, azadirachtin, interferes with mite feeding and reproduction, reducing infestations without harming the plant.

To prepare a spray, dissolve 1–2 ml of 100 % neem oil in 1 L of water and add 0.5 ml of a non‑ionic surfactant (e.g., liquid soap) to improve leaf coverage. Mix thoroughly; the solution remains effective for up to 14 days when stored in a cool, dark container.

Apply the mixture according to the following schedule:

Early morning or late afternoon, when leaf temperature is below 25 °C, to minimize phytotoxic stress.
Cover both upper and lower leaf surfaces, ensuring runoff is avoided.
Repeat every 7–10 days during the active growing season, or after heavy rain that washes the coating away.

Safety considerations include wearing gloves and eye protection, testing the spray on a single leaf for 24 hours before full‑plant application, and avoiding use on seedlings younger than two true leaves. Monitoring mite activity two weeks after each treatment helps confirm efficacy and guides further applications.

Insecticidal Soaps

Insecticidal soaps are a practical tool for managing strawberry mite populations. The products consist of fatty acid salts that dissolve the outer waxy layer of soft‑bodied arthropods, leading to dehydration and death. Because the active ingredients are non‑toxic to mammals and many beneficial insects, soaps can be integrated into a broader pest‑management program without compromising safety.

Effective use requires adherence to specific application parameters.

Concentration: Dilute according to label instructions, typically 1–2 % active ingredient.
Timing: Apply early in the morning or late afternoon to avoid rapid degradation by sunlight.
Coverage: Ensure thorough wetting of foliage, especially the undersides of leaves where mites reside.
Frequency: Repeat every 5–7 days until mite activity declines, then switch to a maintenance schedule of 2–3 applications per month during peak growing periods.

Insecticidal soaps are most successful when combined with cultural practices such as removing plant debris, maintaining adequate spacing for air circulation, and monitoring mite numbers with sticky traps. The soaps do not persist in the environment, reducing the risk of resistance development. However, they are less effective against eggs and may require supplemental measures, such as targeted horticultural oils, to achieve complete control.

Overall, insecticidal soaps provide a fast‑acting, low‑toxicity option for reducing strawberry mite infestations while preserving the ecological balance of the crop ecosystem.

Chemical Pesticides for Severe Infestations

Severe strawberry mite outbreaks demand immediate chemical intervention to prevent yield loss.

Abamectin – a macrocyclic lactone that disrupts nerve transmission; label rates typically range from 0.5 to 1 ml L⁻¹, applied as a foliar spray.
Spirotetramat – a systemic tetramic acid; recommended concentration 0.2 ml L⁻¹, absorbed through roots and leaves, providing control for several weeks.
Pyrethroids (e.g., bifenthrin, lambda‑cyhalothrin) – contact neurotoxins; use 0.1–0.3 ml L⁻¹, re‑apply after 7–10 days if mite pressure persists.
Neonicotinoids (e.g., imidacloprid) – systemic insecticides; apply at 0.05 ml L⁻¹, observe strict pre‑harvest intervals.

Apply treatments early in the morning or late afternoon to reduce photodegradation. Ensure thorough coverage of foliage, especially undersides where mites reside. Rotate chemicals with different modes of action every 7–10 days to delay resistance development.

Observe label‑specified pre‑harvest intervals (typically 3–7 days) and wear protective gloves, goggles, and respirators during mixing and spraying. Avoid runoff into water bodies; use calibrated equipment to minimize excess application.

Combine chemical control with regular scouting, removal of heavily infested leaves, and sanitation of plant debris to sustain long‑term efficacy.

Prevention and Long-Term Management

Maintaining Plant Health

Proper Watering and Fertilization

Proper watering reduces the humidity that favors strawberry mite development. Water the plants early in the day, allowing foliage to dry before nightfall. Avoid overhead irrigation; deliver moisture directly to the soil to keep leaves dry.

Apply 2–3 inches of water per week, adjusting for rainfall.
Use a drip system or soaker hoses to maintain consistent soil moisture.
Stop watering when soil surface is moist to the touch; excess moisture encourages mite proliferation.

Balanced fertilization supports plant vigor without creating conditions that attract mites. Select a fertilizer with a moderate nitrogen ratio (e.g., 10‑10‑10 or 14‑14‑14) and limit nitrogen applications during the fruiting stage, when high nitrogen can increase leaf growth and mite habitat.

Apply fertilizer at planting, then every 4–6 weeks during vegetative growth.
Reduce nitrogen rates by 20 % once berries appear.
Incorporate organic matter such as compost to improve soil structure and promote beneficial microorganisms.

Combining precise watering with judicious fertilization strengthens the plant’s natural defenses, making the environment less suitable for mite colonization. Integrate these cultural practices with monitoring and, when necessary, targeted acaricide treatments for comprehensive control.

Choosing Resistant Varieties

Selecting strawberry cultivars with proven resistance to the two‑spotted spider mite offers a practical line of defense. Resistant varieties reduce mite population growth, lessen the need for chemical interventions, and sustain fruit quality throughout the season.

Key traits to evaluate when choosing a resistant cultivar include:

Resistance rating: documented scores from trials conducted by university extension services or commercial seed companies.
Genetic background: presence of resistance genes derived from wild Fragaria species.
Yield stability: ability to maintain production under moderate mite pressure.
Adaptability: performance in local climate and soil conditions.

Commonly cited resistant cultivars are:

‘Albion’ – high resistance, excellent fruit flavor, suitable for midsummer harvest.
‘Seascape’ – moderate resistance, vigorous runner production, tolerant of wet conditions.
‘Mara des Bois’ – strong resistance, aromatic berries, preferred for specialty markets.
‘Camino Real’ – good resistance, early season fruiting, robust canopy.

When sourcing planting material, obtain certified disease‑free runners or tissue‑culture plants from reputable nurseries. Verify that the supplier provides resistance data specific to the two‑spotted spider mite, not generic pest tolerance.

Integrate resistant varieties with cultural practices such as crop rotation, removal of plant debris, and monitoring of mite populations. This combined approach maximizes control efficacy while preserving ecological balance in the strawberry patch.

Seasonal Monitoring

Early Spring Inspections

Early spring inspections form the first line of defense against strawberry mite infestations. Conduct the survey when buds are swelling and leaves are just unfurling, typically between mid‑March and early April, depending on regional climate. At this stage the mite population is low, making detection and removal most effective.

During the walk through each row, examine the undersides of young leaves and the base of the crown. Look for:

Fine webbing or silk strands, often white or pale yellow.
Discolored or stippled leaf tissue, indicating feeding damage.
Presence of adult mites, which appear as tiny, moving specks, 0.2 mm in length.

Record findings on a field chart, noting plant location, severity, and any visual symptoms. Use a hand lens (10× magnification) for accurate identification. If mite presence exceeds a threshold of five adults per leaf, apply a targeted miticide or introduce predatory insects such as Phytoseiulus persimilis immediately, following label rates.

Repeat inspections weekly until foliage thickens and the risk of rapid mite reproduction declines. Consistent early detection reduces the need for broad‑spectrum chemical treatments and preserves plant vigor throughout the season.

Post-Harvest Care

Effective post‑harvest management is essential for preventing the spread of strawberry mites after picking. Immediate removal of plant debris, careful handling of fruit, and controlled storage conditions reduce mite survival and limit reinfestation of the field.

Separate harvested berries from foliage and weeds before transport.
Wash fruit with a mild, pesticide‑compatible solution (e.g., 0.5 % neem oil or a horticultural oil) to dislodge mites.
Rinse thoroughly with clean water and dry on a perforated tray to avoid moisture buildup.
Store at 0–2 °C with relative humidity below 85 %; low temperature slows mite activity, while reduced humidity prevents fungal growth that can shelter mites.
Inspect batches daily; discard any berries showing visible mite activity or damage.
Clean and disinfect all containers, crates, and transport equipment after each load using a 2 % hydrogen peroxide solution or equivalent sanitizer.
Rotate storage areas regularly to avoid long‑term accumulation of mite populations.

Implementing these practices isolates the pest from the crop, interrupts its life cycle, and supports overall field‑level control efforts. Continuous monitoring and strict sanitation maintain low mite pressure throughout the supply chain.

Integrated Pest Management (IPM) Approach

Combining Multiple Strategies

An integrated approach maximizes effectiveness against strawberry mite infestations by addressing the pest at several points in its life cycle. Combining cultural, biological, chemical, and physical tactics reduces reliance on any single method and lowers the risk of resistance development.

Crop rotation and sanitation: Plant non‑host species for at least two seasons; remove plant debris and weeds that shelter mites.
Resistant varieties: Choose cultivars with documented tolerance to mite damage.
Biological agents: Release predatory insects such as Phytoseiulus persimilis and apply fungal bio‑pesticides containing Beauveria bassiana.
Selective chemicals: Use miticides with different modes of action only when monitoring thresholds are exceeded; alternate products to prevent resistance.
Physical barriers: Install fine mesh row covers early in the season; employ sticky traps to capture dispersing adults.

Synchronizing these measures is essential. Initiate cultural practices before planting, introduce predators as soon as seedlings emerge, and apply miticides only after confirmed population spikes. Timing ensures that each tactic supports the others rather than interfering.

Continuous monitoring validates the program’s success. Record mite counts weekly, compare them to economic thresholds, and adjust the combination of tactics accordingly. Documented reductions in population density confirm that a multi‑strategy regimen effectively suppresses strawberry mite pressure.

Record Keeping for Future Reference

Maintain a detailed log of every action taken against the strawberry mite. Record dates, weather conditions, and the specific cultivar being treated. Note the type of control method applied—chemical, biological, cultural, or mechanical—and the exact product name, concentration, and application rate. Include observations of mite activity before and after treatment, such as leaf damage scores or trap counts.

Document the outcomes of each intervention. Track mortality rates, population trends, and any phytotoxic symptoms. Compare results across seasons to identify patterns, such as increased pressure after warm, dry periods or reduced efficacy of a pesticide after repeated use. Use this information to adjust spray intervals, rotate active ingredients, or introduce supplemental tactics.

Store records in a format that allows quick retrieval and analysis. Digital spreadsheets provide sortable fields and built‑in charts; cloud‑based platforms enable access from multiple locations and automatic backups. Physical notebooks should be organized chronologically, with clear section dividers for each year.

Regularly review the compiled data. Summarize findings in concise tables and graphs to support decision‑making. Share the summary with all personnel involved in field operations to ensure consistent implementation of proven strategies.

By adhering to systematic record keeping, future interventions become evidence‑based, reducing trial‑and‑error and improving long‑term control of the strawberry mite.