Pests

Strawberry Bud Mite (Tarsonemus fragariae)

This pest is one of the most serious and insidious for strawberries worldwide (Kirtbaya and Shcheglov, 2003; Dankov, 2015). Its microscopic size (less than 0.2 mm) makes it virtually invisible to the naked eye, and its high fertility allows it to quickly overtake large areas.

Why it's dangerous: The mites suck juices from young, unexpanded leaves. As a result, plants stop developing, leaves become small, wrinkled, and curled, and bushes take on a dwarfed appearance. Young runners are particularly affected, through which the mite easily spreads across the plot. Females overwinter at the base of leaf petioles and in spring move to young leaves to lay eggs. 3–4 generations of the pest can develop per season (Dankov, 2015). Infested plants sharply reduce yield, and berries become smaller and lose their marketable appearance.

Signs of infestation: Severe deformation and crinkling of young leaves, which appear to "shrivel" and fail to unfold. The bush looks stunted and dwarfed.

Stem Nematode (Ditylenchus dipsaci)

This is a microscopic worm (about 1 mm) that lives inside plant tissues. Unlike other pests, the nematode penetrates the plant's vascular system, making it particularly dangerous (Kirtbaya and Shcheglov, 2003).

Why it's dangerous: Nematodes feed on cell sap, damaging stems, leaves, and petioles. In the early stages, infestation is difficult to detect, but over time the plant begins to lag significantly in growth. Leaves become wrinkled, crinkled, and curled, petioles thicken and become distorted. Flower stalks shorten, berries become small and tough (Kirtbaya and Shcheglov, 2003; Dankov, 2015). Over a season, the stem nematode can produce 4–5 generations, spreading rapidly through the plot with planting material, water, and soil. A particular feature of this pest is its ability to survive without host plants for several years, making control extremely difficult.

Signs of infestation: Dwarfed bushes, crinkled and thickened leaf blades, shortened and distorted petioles and flower stalks.

Two-Spotted Spider Mite (Tetranychus urticae)

Unlike the strawberry bud mite, the two-spotted spider mite is more widespread and aggressive in hot, dry weather (Rieger, 2010; Sharma et al., 2019). It can be detected by the characteristic fine webbing on the underside of leaves.

Why it's dangerous: Mites colonize the underside of leaves, piercing cells and sucking out sap. This leads to the appearance of tiny light spots ("puncture marks") on the upper side of leaves, which then merge, causing yellowing, wilting, and drying of leaves. The plant loses photosynthetic surface area, leading to a significant reduction in yield and deterioration of berry quality (Rieger, 2010; Sharma et al., 2019). Over a season, the two-spotted spider mite produces up to 10 generations, reproducing especially rapidly at temperatures above 25°C and low humidity.

Signs of infestation: Fine light speckling (spot necrosis) on the upper side of leaves, presence of fine webbing on the underside, especially along edges and near petioles. In severe infestations, leaves become bronze or yellow and dry up.

Strawberry Blossom Weevil (Anthonomus rubi)

This is one of the most noticeable and troublesome pests because it attacks flowers and buds, depriving us of future yield (Bianchi, 2018; Kirtbaya and Shcheglov, 2003).

Why it's dangerous: The beetle chews a hole in the side of a bud, lays an egg inside, and gnaws through the flower stalk. The bud droops, dries up, and falls off without opening. The larva feeds inside the fallen bud. Thus, one beetle can destroy several flowers, sharply reducing yield. The greatest damage is inflicted on early strawberry varieties (Kirtbaya and Shcheglov, 2003). Beetles initially feed on strawberries and, after flowering ends, move to raspberries, where the reproductive cycle continues.

Signs of infestation: Numerous drooping, dried buds on thin flower stalks that easily detach and fall off.

Slugs and Snails (Arion hortensis and other species)

These are not insects but gastropod mollusks, yet they cause enormous damage, especially in rainy years and in areas with high humidity (Kirtbaya and Shcheglov, 2003; Sharma et al., 2019).

Why they're dangerous: Slugs are active mainly at night or in cloudy weather. They chew large, irregularly shaped holes in leaves and, most unpleasantly, in ripe berries. They eat out the flesh, leaving characteristic ulcers and slime trails on the fruit. Damaged berries quickly rot and become unfit for consumption. Slugs prefer juicy dessert varieties of strawberries.

Signs of infestation: Eaten leaves with uneven edges, large holes and gouges in ripe berries, presence of a silvery slime trail on leaves, berries, and soil.

Aphids (Chaetosiphon fragaefolii, Aphis gossypii, and others)

Although aphids themselves do not cause colossal direct damage to strawberries in open ground, their danger lies in transmitting viruses (Bianchi, 2018; Sharma et al., 2019). This makes them one of the most insidious pests, especially on mother plantings where planting material is grown.

Why they're dangerous: Aphids suck sap from young leaves, causing them to curl and deform. But the main threat is their ability to transmit various viruses (mosaic, speckle, etc.) from infected plants to healthy ones. Viral diseases are incurable and lead to gradual varietal degeneration, reduced yields, and deterioration of berry quality (Bianchi, 2018). The sweet honeydew secreted by aphids promotes the development of sooty mold, which covers leaves with a black coating, impairing photosynthesis.

Signs of infestation: Curled, deformed young leaves; colonies of small light or dark insects on the underside of leaves and on petioles; sticky shiny coating on leaves.

As you can see, each pest has its own "specialization" — some attack leaves, others roots or berries. In the following chapters, we will discuss in detail how to identify them by the nature of damage and which protection methods are most effective at each stage.

Strawberry Leaf Beetle (Galerucella tenella)

This is a small brown beetle up to 4 mm long, and its larvae are yellowish with dark spots on their backs (Kirtbaya and Shcheglov, 2003). This is one of the most common specialized strawberry pests in many regions.

Nature of damage: Beetles overwinter under plant debris. In spring, they emerge and begin actively feeding on leaves, chewing irregularly shaped holes through them. However, the larvae, which develop on the underside of the leaf, are most dangerous. They eat the flesh, leaving the veins intact, so the leaf resembles a net or skeleton (Kirtbaya and Shcheglov, 2003). Such "skeletonization" sharply reduces the photosynthetic area and exhausts the plant.

Signs: Presence of round holes (from adult beetles) and characteristic "transparent" areas with intact veins (from larval feeding) on leaves. Clusters of larvae are most often found on the underside of leaf blades.

Two-Spotted Spider Mite (Tetranychus urticae)

In Chapter 1, we already mentioned it as one of the most dangerous pests. In relation to leaves, its role can hardly be overstated. It is active in hot, dry weather, and its populations can grow at catastrophic speed (Rieger, 2010; Sharma et al., 2019).

Nature of damage: Mites colonize the underside of the leaf, piercing the epidermis and sucking out cell contents. On the upper side, multiple tiny light spots (chlorotic spots) appear, which merge over time; the leaf becomes pale, then yellow, and dries up. In severe infestations, fine webbing appears on the underside and between leaves. Unlike many other pests, the two-spotted spider mite does not just weaken the plant — it can kill it in advanced cases.

Signs: Light speckling, yellowing and drying of leaves, presence of webbing. Under magnification or with a magnifying glass, mobile, very small (about 0.5 mm) spider-like mites can be seen on the underside.

Strawberry (Bud) Mite (Tarsonemus fragariae)

Unlike the spider mite, this mite prefers young, unexpanded leaves. It is also extremely small, and its presence is indicated not so much by spots or webbing but by deformation of leaf blades (Kirtbaya and Shcheglov, 2003; Dankov, 2015).

Nature of damage: Mites feed on the sap of the youngest leaves in the center of the rosette. As a result, leaves cannot unfold properly — they become small, wrinkled, crinkled, and take on a yellowish tinge. Leaf petioles shorten and thicken. The bush looks dwarfed and stunted. Such plants rarely produce a good harvest because their photosynthesis is sharply reduced.

Signs: Severe deformation, crinkling, and wrinkling of young central leaves; the bush appears to "shrivel." Leaves do not attain the size and shape characteristic of the variety.

Aphids (Chaetosiphon fragaefolii — strawberry aphid, Aphis gossypii — melon/cotton aphid, and others)

As mentioned in the first chapter, aphids are dangerous primarily as virus vectors. However, they also cause direct damage to leaves (Bianchi, 2018; Sharma et al., 2019).

Nature of damage: Aphids colonize the underside of young leaves, petioles, and flower stalks. By sucking sap, they cause leaves to curl, turn yellow, and stunt growth. A sticky "honeydew" appears on leaves, on which sooty mold settles, covering the leaf blade with a black coating. This impairs respiration and photosynthesis. But again, the main threat is the viruses that aphids transmit from plant to plant, and such diseases are incurable (Bianchi, 2018).

Signs: Curled, deformed young leaves; clusters of small (1–2 mm) insects of various colors (green, yellow, dark) on the underside; sticky coating on leaves and appearance of black sooty mold.

Stem and Strawberry Nematodes

Both nematodes (we discussed the stem nematode in the first chapter, and the strawberry nematode is similar) affect not only stems and petioles but also leaf blades. When affected by nematodes, leaves become wrinkled, curled, with crinkled edges, and sometimes swellings and yellowish spots appear (Kirtbaya and Shcheglov, 2003). Petioles thicken, become distorted, and leaves become smaller. Affected plants appear stunted and lag in growth.

Signs: Wilting and deformation of leaves without clear signs of chewing or puncture marks; characteristic thickening and distortion of petioles; general dwarfing of the bush. Nematodes are microscopic, so their presence is confirmed by symptoms.

Other Leaf-Chewers

In addition to those listed, sawfly larvae, leafroller caterpillars, and other butterflies may be found on strawberry leaves. They may chew the edges of leaves, roll them into tubes, or wrap them in webbing. However, in most regions, they do not reach mass distribution and do not cause as much serious damage as mites or weevils. Nevertheless, when clusters are found, it is recommended to collect them manually or use biological preparations (for example, based on Bacillus thuringiensis).

It is important to understand that leaf damage is not just an aesthetic problem. Every damaged leaf reduces nutrient accumulation, which ultimately affects the current and next year's harvest. Therefore, regular inspection of plantings is the foundation of successful protection.

Strawberry Blossom Weevil (Anthonomus rubi)

This is undoubtedly the most famous and dangerous pest of strawberry flower buds (Kirtbaya and Shcheglov, 2003; Dankov, 2015; Bianchi, 2018). A small (2–3 mm) grayish-black beetle with a long snout.

Nature of damage: The female weevil chews a hole in the side of the bud, lays one egg inside, and then gnaws through the flower stalk. As a result, the bud droops, dries up, and falls off without opening. The larva that hatches from the egg feeds on the contents of the bud from within. Thus, one beetle can destroy several buds. The pest's peak activity coincides with the budding and early flowering period of strawberries (Kirtbaya and Shcheglov, 2003). The greatest damage is inflicted on early varieties. After strawberry flowering, the beetles fly to raspberries, where the reproductive cycle continues, making the crop a carrier of the pest.

Signs: Numerous drooping, dried buds on thin flower stalks that easily detach from the plant. A small hole made by the beetle can sometimes be seen on buds. Fallen buds containing larvae can often be found under bushes.

Plant Bugs (Lygus spp.), or Tarnished Plant Bugs

These small (about 5–6 mm) insects with characteristic membranous wings are active during flowering and fruit set. They do not specialize only in strawberries but often cause serious damage to them (Rieger, 2010; Sharma et al., 2019; Bowling, 2000).

Nature of damage: Bugs pierce flower buds, blossoms, and young ovaries with their mouthparts, sucking out sap. As a result, tissues are damaged, and developing fruits become deformed. This phenomenon is known as "catfacing": berries become ugly, bumpy, with dents and underdeveloped areas (Sharma et al., 2019; Rieger, 2010). Damaged flowers may not set fruit at all. Bugs are active in warm weather, and their numbers can increase sharply in years with mild winters.

Signs: Presence of irregularities, dents, areas with underdeveloped seeds on berries; deformed "beak" at the tip of the fruit. Bugs themselves can be seen on flowers and young leaves in the morning when they are less active.

Thrips (mainly Frankliniella occidentalis — Western Flower Thrips)

Thrips are tiny (1–2 mm), highly mobile insects with narrow fringed wings. They feed on plant cell sap, preferring flowers and young tissues (Sharma et al., 2019).

Nature of damage: Thrips pierce cells of petals, stamens, and pistils. This leads to the appearance of small discolored spots, deformation of flowers, and premature wilting of petals. Severely damaged flowers do not get pollinated and do not set fruit. In addition, thrips can transmit viruses that further weaken the plant. In hot, dry weather, their populations grow very quickly.

Signs: Discolored, shriveled petals; flowers appear underdeveloped; small light streaks and spots visible on petals. Under magnification, small elongated insects that crawl or fly quickly can be seen on flowers.

Other Pests

Sometimes, larvae of certain beetles (e.g., scarab beetles) or leafroller caterpillars may feed on flowers, but they are not specialized strawberry pests and cause damage only at very high population densities, which is rare. In such cases, manual collection helps.

Slugs and Snails (Arion hortensis, Deroceras spp., and others)

These gastropod mollusks are among the most unpleasant and noticeable berry pests (Kirtbaya and Shcheglov, 2003; Sharma et al., 2019). They are particularly active in rainy, humid weather and at night, hiding during the day under plant debris, boards, or in the topsoil.

Nature of damage: Slugs eat large, irregularly shaped cavities in berries, often starting from the lower side touching the soil. Characteristic silvery slime trails remain on the berry surface. Damaged berries rot quickly, become unfit for consumption, and can become a source of infection for neighboring fruits. Large, sweet dessert varieties are especially affected (Kirtbaya and Shcheglov, 2003). In wet years, slugs can destroy a significant portion of the harvest.

Signs: Presence of large, irregularly shaped eaten-out cavities on berries, especially on the side lying on the ground. Characteristic silvery, shiny slime trail on berries, leaves, and soil. When turning over mulch or boards, the pests themselves can be found.

Sap Beetles (Stelidota geminata and others)

These small (about 3–4 mm) dark brown or black beetles, also known as "raspberry beetles" or "picnic beetles," are attracted to the smell of overripe or damaged berries (Bianchi, 2018; Bowling, 2000; Hill & Perry, 2011).

Nature of damage: Beetles chew small holes in berries and eat the flesh. They often attack already damaged fruits (e.g., after slugs or birds), deepening damage and promoting rot. Beetles are especially active during harvest ripening. Their larvae can develop inside berries, making them unfit for consumption. The problem is compounded by the fact that beetles can carry spores of fungi that cause gray mold.

Signs: Presence of small holes and eaten-out areas on berries, especially around the calyx. Damaged berries become soft, watery, and rot quickly. Small white larvae can be found inside berries.

Plant Bugs (Lygus spp.)

As mentioned in the previous chapter, bugs damage flowers and ovaries, leading to berry deformation. But their impact is not limited to shape alone. Areas of the berry damaged by bugs do not develop, remain hard and light-colored, making the fruit unattractive ("catfacing") (Rieger, 2010; Sharma et al., 2019; Bowling, 2000).

Nature of damage: Bugs pierce young ovaries and suck sap, disrupting normal tissue development. As a result, depressed areas, bumps, and an ugly shape appear on ripe berries. Such fruits lose marketable appearance and are often unsuitable for fresh consumption, although their taste may remain acceptable.

Signs: Deformed berries with dents, bumps, and underdeveloped areas. Particularly characteristic is the presence of "catfacing" — a wrinkled, depressed tip of the berry.

Thrips (mainly Frankliniella occidentalis)

Thrips damage not only flowers but also young, developing berries (Sharma et al., 2019). Their feeding leads to the appearance of small rough spots on the berry surface, the so-called "russeting." Berries become rough, brownish, lose their shine and marketable appearance. In severe infestations, berries may crack.

Nature of damage: Thrips suck sap from epidermal cells of the berry, causing tissue death and crust formation. Small discolored or brownish areas appear on the surface, which may merge. The berry feels rough to the touch and loses its characteristic varietal shine.

Signs: Small, often concentric, rough or brown spots on the berry surface. In severe infestation, the berry may be completely covered with such "russeting."

Birds

Although birds are not insects, they can cause serious damage to berry crops, especially in regions where wild birds are numerous (Buckingham, 2010; Sharma et al., 2019). Thrushes, starlings, sparrows, and other species happily eat ripe berries.

Nature of damage: Birds peck berries whole or eat large sections. Damaged berries become unfit for consumption and often serve as entry points for fungal infections. Unlike slugs, birds leave ragged, uneven edges and no slime trail.

Signs: Partially or completely eaten berries, often with characteristic pecked-out areas. Berries may simply be torn from the bush and lie nearby. Presence of birds on the site is an additional signal.

Stem Nematode (Ditylenchus dipsaci)

In the first chapters, we already mentioned the stem nematode as a dangerous pest of leaves and stems. However, its destructive action begins with the root system and the base of the bush (Kirtbaya and Shcheglov, 2003; Dankov, 2015). This microscopic worm penetrates plant tissues through the roots and moves upward through the vascular system.

Nature of damage: The nematode penetrates roots and the base of the stem (crown), feeding on cell sap and destroying tissues. This disrupts the vascular system: the plant cannot receive sufficient water and nutrients, even if the soil is moist. Roots become brown, rot, and lose their ability to absorb water. The above-ground part begins to wilt, leaves become smaller and crinkled, and flower stalks shorten (Kirtbaya and Shcheglov, 2003). The pest is very resilient: it can survive in soil for several years even without host plants and overwinters inside plant debris and roots.

Signs: Sudden or gradual wilting of plants, especially in hot weather, even with adequate watering. Plants appear dwarfed, leaves deformed, petioles thickened. When dug up, roots are brown or black and show signs of rot.

Strawberry Nematode (Aphelenchoides fragariae)

This is another species of microscopic worms specializing in strawberries. Unlike the stem nematode, the strawberry nematode prefers above-ground organs but can also damage roots, especially under high humidity conditions (Bianchi, 2018; Dankov, 2015).

Nature of damage: The strawberry nematode feeds on young leaves, buds, and at the base of petioles. This leads to deformation of leaf blades, thickening of petioles, and shortening of flower stalks. Plants become dwarfed, berries small and tough (Dankov, 2015). In the root system, damage manifests as brown necrosis and rot. Over a season, the nematode produces up to 6–9 generations, spreading rapidly with planting material and through soil.

Signs: Similar to stem nematode damage: dwarfing, deformation of leaves and flower stalks. However, the strawberry nematode more often affects leaves and buds than roots, but in wet conditions, roots can also be damaged.

Root Weevils (Otiorhynchus spp.)

Root weevils are a group of beetles whose larvae live in the soil and feed on plant roots (Crandall, 1994; Bowling, 2000; Rieger, 2010). Adult beetles (black or brown, up to 10 mm long) feed on leaves, chewing characteristic notches along the edges, but the main damage is caused by larvae.

Nature of damage: Weevil larvae are thick, legless, C-shaped, worm-like creatures that are white or cream-colored. They live in the soil and feed on fine absorbing roots and may also chew cavities in the rhizome and at the base of the stem (Crandall, 1994). As a result, the root system is destroyed, the plant stops receiving adequate nutrition, begins to wilt, and may die. Larvae are particularly dangerous for young plants and on mother plantings. Adult beetles often become a serious contaminant of the harvest during machine harvesting, as they fall into the berries (Crandall, 1994).

Signs: Characteristic semicircular notches along the edges of leaves (from adult beetle feeding). Plants lag in growth, leaves yellow, and the bush pulls out of the soil easily. When dug up, roots show damage, may be gnawed, and the rhizome shows signs of feeding.

Chafer Beetle Larvae (May Beetles) and Other Scarab Beetles (Phyllophaga spp., Melolontha spp.)

May beetle larvae are large (up to 3–4 cm), thick, white or yellowish worms with a characteristic C-shape and a dark head. They live in the soil for several years, feeding on the roots of various plants, including strawberries (Bowling, 2000; Hill & Perry, 2011; Sharma et al., 2019).

Nature of damage: Larvae eat roots, especially fine absorbing roots, weakening the plant. At high population densities, they can completely destroy the root system, and the plant dies. Larvae are especially dangerous on new plantations established on land previously in sod or perennial grasses (Bowling, 2000). Adult beetles (May beetles) feed on leaves of trees and shrubs but do not pose a direct threat to strawberries.

Signs: Sudden wilting and death of plants, especially in hot weather. Bushes pull out of the soil easily. When dug up, characteristic white or yellowish larvae with dark heads, curled into a ring, are found.

Wireworms (Click Beetle Larvae, Agriotes spp.)

These are hard, thin, cylindrical, yellowish-brown larvae, up to 2–3 cm long. They get their name from their characteristic hardness and elasticity. Wireworms live in the soil for several years, feeding on underground plant parts (Crandall, 1994; Hill & Perry, 2011).

Nature of damage: Wireworms gnaw roots, stems at the base, and may even damage berries lying on the ground. They make narrow, deep tunnels in the root collar and roots, disrupting the vascular system. Plants weaken, begin to wilt, and may die. Wireworms are especially active in moist, acidic soils.

Signs: Wilting and death of individual plants. When dug up, narrow, elongated tunnels can be found in roots and at the base of the stem. The pests themselves can be found in the soil around damaged plants.

Mole Cricket (Gryllotalpa gryllotalpa)

In some regions, serious root damage can be caused by the mole cricket — a large (up to 5 cm) brownish insect with powerful digging legs. It lives in the soil, making tunnels, and gnaws through roots and stems of plants, damaging them.

Nature of damage: The mole cricket gnaws through roots and the root collar, causing rapid wilting and death of the plant. It prefers moist, loose soils and is often found near water bodies.

Signs: Presence of tunnels and loose soil mounds on the surface; wilting and death of plants that easily pull out of the soil; damaged roots with jagged edges.

Step 1. Determine Which Part of the Plant Is Damaged

This is the quickest way to narrow down the search.

Step 2. Refine the Diagnosis by Damage Type

Once you have identified which part of the plant is affected, look closely at the details.

Step 3. Conduct a Targeted Inspection

After you have identified the likely pest based on damage type, conduct a targeted inspection to confirm:

• For mites and aphids: Turn the leaf over and inspect the underside with a magnifying glass. Mites are very small (0.2–0.5 mm), but their colonies and webbing are visible. Aphids are noticeable to the naked eye.
• For weevils: Inspect fallen buds — they may contain larvae or pupae.
• For slugs: Look under mulch, boards, stones, especially in wet weather. Slugs can be found by their characteristic slime trail.
• For root pests: Carefully dig up a suspicious plant and inspect the roots and base of the stem.
• For birds: Simply observe the area — often the pests are visible.

Step 4. Consider Seasonality and Weather

Some pests become active at certain times of the year or under specific weather conditions:

• Spring, early summer: Weevils, strawberry leaf beetle, aphids.
• Dry and hot weather: Two-spotted spider mite, thrips.
• Wet, rainy weather: Slugs, sap beetles, nematodes (especially active at high humidity).
• Second half of summer: Two-spotted spider mite, sap beetles.

Using this diagnostic system, you will be able to quickly and accurately identify what is threatening your strawberries and take appropriate protection measures. Remember that plants are often affected by multiple pests simultaneously, so it is important to conduct regular inspections and not rely on a single sign.

In the next chapter, we will move on to prevention — how to make your plantation less attractive to pests and reduce the risk of infestation to a minimum.

7.1. Choosing Healthy Planting Material

This is the most important and simplest step. Many pests (especially nematodes, mites, and virus-transmitting aphids) arrive on the site with infected planting material (Bianchi, 2018; Kirtbaya and Shcheglov, 2003; Sharma et al., 2019).

Why it's important: Nematodes and mites can live inside plant tissues and cannot be detected by superficial inspection. One infected bush can become a source of infection for the entire plantation (Kirtbaya and Shcheglov, 2003).

What to do:

• Purchase planting material only from verified nurseries and reliable suppliers.
• Prefer varieties resistant to major pests and diseases (Bianchi, 2018; Bowling, 2000).
• If you use your own runners for propagation, take them only from healthy, well-developed bushes that have shown no signs of pest infestation throughout the season.
• Before planting, carefully inspect the seedlings: roots should be light-colored, without swellings or dark spots; leaves without deformations or spots.

7.2. Crop Rotation

Strawberries should not be grown in the same place for more than 3–4 years. This rule is well known, but its importance for pest prevention cannot be overstated (Bianchi, 2018; Crandall, 1994; Hill & Perry, 2011).

Why it's important: Many pests and disease pathogens accumulate in the soil. Nematodes, weevil larvae, wireworms, and root rot pathogens all remain in the ground after plants are removed and can attack new plantings (Crandall, 1994).

What to do:

• Return strawberries to the same site no earlier than after 4–5 years (Kirtbaya and Shcheglov, 2003; Bianchi, 2018).
• The best preceding crops for strawberries are green manures (mustard, phacelia, rye), cereals, and legumes.
• Avoid planting after nightshades (potatoes, tomatoes, peppers, eggplants), as they share common pests and diseases with strawberries (e.g., nematodes and Verticillium wilt) (Bowling, 2000).
• After removing an old plantation, it is advisable to sow green manures and incorporate them into the soil — this improves soil health and reduces pest numbers.

7.3. Proper Care of Plantings

Healthy, strong plants resist pests much better than weakened ones. Proper care is not only a guarantee of a good harvest but also a natural defense.

Why it's important: Weakened plants are more vulnerable to pests. For example, two-spotted spider mites and aphids prefer plants experiencing stress from lack of moisture or excess nitrogen fertilizers (Hill & Perry, 2011). Dense plantings create a favorable microclimate for the development of mites, aphids, and slugs (Bianchi, 2018).

What to do:

• Maintain optimal planting density: Dense plantings are poorly ventilated, creating conditions for mite and aphid reproduction (Bianchi, 2018).
• Regularly weed and loosen the soil: This destroys weeds — potential shelters for pests — and disrupts their overwintering conditions (Kirtbaya and Shcheglov, 2003).
• Provide moderate watering: Excess moisture promotes slug reproduction and the development of root rots, while deficiency weakens plants and makes them attractive to two-spotted spider mites (Bowling, 2000; Rieger, 2010).
• Do not overfeed with nitrogen fertilizers: Excess nitrogen stimulates rapid growth of soft, succulent tissues that are particularly attractive to aphids and mites (Hill & Perry, 2011).
• Regularly prune and remove old leaves: After harvest, mowing and removing old leaves is one of the most effective measures against overwintering pest stages (Kirtbaya and Shcheglov, 2003). This disrupts the pests' development cycle and removes their overwintering sites.

7.4. Mulching

Mulching is not only an agronomic technique for moisture conservation and soil improvement but also a powerful tool for pest prevention (Bianchi, 2018; Bowling, 2000; Hill & Perry, 2011).

Why it's important: Mulch creates a barrier between berries and the soil, significantly reducing damage from slugs and sap beetles (Bianchi, 2018). Additionally, reflective mulch (e.g., black-and-white or silver) disorients aphids and thrips, reducing their numbers (Mandal et al., 2021).

What to do:

• Use clean straw (not hay!) for mulching strawberries. Straw contains no weed seeds and does not attract slugs as strongly as hay (Bianchi, 2018).
• Consider using black-and-white or silver polyethylene mulch: the white side reflects light, reducing the attractiveness of plants to aphids and thrips (Mandal et al., 2021).
• Regularly refresh mulch, especially after rains.

7.5. Destruction of Plant Residues

Old leaves, diseased berries, and plant debris are ideal places for pest overwintering and disease development (Bianchi, 2018; Hill & Perry, 2011; Crandall, 1994).

Why it's important: Many pests (strawberry leaf beetle, strawberry blossom weevil, mites, nematodes) overwinter precisely in plant residues. If they are not removed, the pest population will only increase year after year (Kirtbaya and Shcheglov, 2003).

What to do:

• After harvest, mow and remove old strawberry leaves (especially those showing signs of damage). This removes a significant portion of overwintering pests (Kirtbaya and Shcheglov, 2003; Crandall, 1994).
• Collect and destroy all affected berries — they can be a source of infection and a breeding ground for sap beetles and other pests (Bianchi, 2018; Bowling, 2000).
• Remove and burn severely affected plants (especially in the presence of nematodes or root rots) (Kirtbaya and Shcheglov, 2003).

7.6. Creating Conditions for Natural Enemies of Pests

In nature, there are many predators and parasitoids that feed on strawberry pests: ladybugs, lacewings, predatory mites, hoverflies, and others (Hill & Perry, 2011; Sharma et al., 2019; Mandal et al., 2021). Attracting and preserving these beneficial organisms is a natural and safe way to control pest populations.

Why it's important: Natural enemies can effectively suppress pest populations, especially aphids and mites, without the use of chemical agents (Sharma et al., 2019).

What to do:

• Plant nectar-producing plants near strawberries (dill, fennel, phacelia, flowers of the umbelliferous and aster families) that attract predatory insects (Hill & Perry, 2011).
• Avoid excessive use of chemical insecticides, especially broad-spectrum ones, which also kill beneficial insects (Sharma et al., 2019; Hill & Perry, 2011).
• Use biological protection methods (see next chapter) that do not harm natural pest enemies.

7.7. Winter Protection

Proper winter preparation helps reduce the number of overwintered pests in spring (Bowling, 2000; Hill & Perry, 2011).

Why it's important: Many pests overwinter in the topsoil, under plant debris, or in mulch. If unfavorable conditions are created for them, their spring population will be significantly smaller.

What to do:

• In autumn, before persistent frosts set in, cover strawberries with straw or other breathable material. This protects the roots from freezing and creates a barrier against pests overwintering in the soil (Bowling, 2000).
• In early spring, as soon as the snow melts, remove the winter cover so that the plants do not become waterlogged, and any pests that may have overwintered there are removed from the site (Hill & Perry, 2011).

Prevention is not a one-time action but a system of measures carried out throughout the season. It requires time and attention but pays off handsomely: healthy plants, quality harvest, and no need to use chemical plant protection agents. Remember that preventive measures must be regular and comprehensive — only then will they give maximum effect.

In the next chapter, we will move on to protection methods — the actions that need to be taken if prevention has not helped and pests have still appeared on the site.

8.1. Agrotechnical Methods

Agrotechnical methods are physical and mechanical control methods that do not require the use of any substances. They are safe for humans and the environment and are the first line of defense.

Manual Collection and Removal

This is the simplest and most environmentally friendly method, particularly effective when pest numbers are low.

• Collecting beetles: Early in the morning, when beetles are sluggish, they can be shaken off plants onto spread fabric or paper and destroyed (Kirtbaya and Shcheglov, 2003). This method is especially effective against the strawberry blossom weevil and strawberry leaf beetle.
• Collecting damaged buds: When weevils are present, it is necessary to collect and destroy fallen, damaged buds that contain larvae (Kirtbaya and Shcheglov, 2003). This interrupts the pest's reproductive cycle.
• Collecting damaged berries: Regular collection and destruction (preferably burning) of all damaged, overripe, or rotting berries reduces the numbers of sap beetles and slugs (Bianchi, 2018; Bowling, 2000).

Traps

Traps are an effective way to reduce the numbers of certain pests without using chemicals.

• Slug traps: Place damp boards, pieces of cardboard, or cabbage leaves between rows and around bushes. During the day, slugs will hide under them and can be collected and destroyed (Kirtbaya and Shcheglov, 2003). Beer traps are also effective — shallow containers half-filled with beer (preferably dark) (Bowling, 2000; Buckingham, 2010). Slugs are attracted by the smell and drown.
• Beetle traps: Red or yellow sticky traps are used to catch adult weevils and other beetles (Hill & Perry, 2011). Pheromone traps help monitor and reduce the numbers of certain pests, such as the strawberry blossom weevil.
• Wireworm and chafer larva traps: Pieces of raw potato or carrot buried in the soil at a depth of 5–10 cm attract larvae. After a few days, they are dug up along with the pests and destroyed.

Physical Barriers

• Mulching: As mentioned in the prevention chapter, mulch not only improves growing conditions but also creates a barrier between berries and the soil, protecting them from slugs and sap beetles (Bianchi, 2018). Clean straw is especially effective.
• Nets and covers: Special nets stretched over the plantation are used to protect against birds (Sharma et al., 2019; Buckingham, 2010). It is important that the net does not touch the berries, otherwise birds may reach them through the mesh.
• Covering material: During flowering and berry ripening, thin covering material can be used to protect against insect pests, but it must be removed during flowering for pollination.

Heat Treatment

To control nematodes and mites on planting material, heat treatment is used (Kirtbaya and Shcheglov, 2003).

How it works: Nematodes and many mites die at temperatures of 45–48°C. Treatment involves immersing seedlings in hot water for a specific time (e.g., 15–20 minutes at 48°C for nematode control) (Kirtbaya and Shcheglov, 2003). It is important to strictly observe the temperature and time to avoid damaging the plants themselves. This method requires caution and skill.

8.2. Biological Methods

Biological methods involve the use of living organisms to control pest populations. This is the most environmentally friendly and promising approach, actively developing in modern agriculture.

Natural Enemies of Pests

Attracting and preserving predators and parasitoids is one of the cornerstones of integrated protection (Hill & Perry, 2011; Sharma et al., 2019).

• Predatory mites (Phytoseiulus persimilis, Neoseiulus californicus): These microscopic predators feed on two-spotted spider mites and are their natural enemies (Sharma et al., 2019). They can be purchased from specialized biological laboratories and released onto the plantation. They are especially effective in greenhouses and under high humidity.
• Ladybugs and lacewings: These well-known insects and their larvae actively eat aphids, mites, and small caterpillars (Hill & Perry, 2011). To attract them to the site, plant nectar-producing plants (dill, fennel, phacelia) and avoid using broad-spectrum insecticides.
• Hoverflies (syrphid flies): Their larvae also actively feed on aphids. Adult flies pollinate plants, while larvae destroy pests (Hill & Perry, 2011).
• Parasitic wasps: Some wasp species lay eggs inside aphids or caterpillars, destroying them from the inside. This is a natural and very effective control mechanism (Sharma et al., 2019).

Microbiological Preparations (Biopesticides)

These are preparations based on bacteria, fungi, or viruses that affect specific pests.

• Bacteria Bacillus thuringiensis (Bt): Preparations based on this bacterium are effective against caterpillars (leafrollers, cutworms) (Hill & Perry, 2011). The bacterium affects the caterpillar's gut, causing death. The preparation is safe for humans, animals, and beneficial insects, but is effective only against young caterpillars.
• Entomopathogenic nematodes (Steinernema, Heterorhabditis): These microscopic worms penetrate the bodies of larvae (wireworms, chafer larvae, weevils), release symbiotic bacteria, and kill the pest (Sharma et al., 2019; Crandall, 1994). They are used for soil treatment and are very effective against soil pests.
• Fungus Beauveria bassiana: This fungus infects many insects, germinating through their cuticles and causing death. It is used against aphids, mites, and other pests (Sharma et al., 2019).
• Avermectins (preparations based on bacterium Streptomyces avermitilis): These are biological insecticides and acaricides used against mites, thrips, and other pests. They have high efficacy with relatively low toxicity (Sharma et al., 2019).

Advantages of biological methods:

• Environmental safety.
• Selective action (affect only specific pests).
• Do not disturb the natural balance of the ecosystem.
• Can be very effective when applied correctly.

Limitations:

• Slower action compared to chemical preparations.
• Require specific conditions (temperature, humidity).
• May be more expensive than chemical agents.

8.3. Chemical Methods

Chemical methods involve the use of insecticides (against insects), acaricides (against mites), and nematicides (against nematodes). This is the fastest and most reliable way to control pests during mass outbreaks, but it requires special care and responsibility.

When to apply:

Chemical agents should be used only in the following cases:

• When the pest population has reached the economic threshold of harmfulness (i.e., can cause significant yield loss).
• When other methods (agrotechnical and biological) have not produced results.
• During mass outbreaks of particularly dangerous pests (e.g., two-spotted spider mites in hot, dry weather, or nematodes on mother plantings).

Rules for safe use:

1. Strictly follow the instructions: Read the label before each application. Dosage, application timing, and pre-harvest interval (time from last treatment to harvest) may vary depending on the preparation (Hill & Perry, 2011; Kirtbaya and Shcheglov, 2003).

2. Use selective preparations: Whenever possible, choose products that target specific pests rather than killing all insects indiscriminately. This preserves beneficial insects and natural pest enemies (Sharma et al., 2019).

3. Apply at the right time:

• Before flowering: against weevils, leaf beetles, aphids (Kirtbaya and Shcheglov, 2003).
• During flowering: avoid insecticide treatments entirely to avoid killing bees and other pollinators (Hill & Perry, 2011).
• After harvest: remove and mow leaves, treat against mites and nematodes (Kirtbaya and Shcheglov, 2003).
• Observe the pre-harvest interval: The specified time (usually 7–14 days) must pass after treatment before berry picking (Hill & Perry, 2011).
• Use personal protective equipment: When working with chemical preparations, always use gloves, a respirator, and safety glasses (Kirtbaya and Shcheglov, 2003).
• Do not exceed the dosage: This will not enhance the effect but may cause plant burns and soil contamination.

Main groups of chemical preparations for strawberry protection:

Important! Specific approved preparations and their names vary by country and region. Always check current information with local plant protection services or horticultural advisors. The table provides examples of active ingredients, not trade names.

Choosing a Protection Method

Which method to choose depends on the situation:

Remember that there is no universal recipe. Successful protection of strawberries from pests is a comprehensive approach based on regular observations, timely preventive measures, and competent application of protection methods depending on the specific situation. Be attentive to your plants, and they will reward you with an abundant and healthy harvest!