Strawberry crops are susceptible to various pests that can pose significant challenges to their growth and productivity. These pests can damage the leaves, stems and fruits of strawberry plants, leading to reduced vigour, poor fruit quality, and yield losses. Common pests that affect strawberries include:

Aphids

Aphids are a common pest in strawberry crops and can cause significant damage if left uncontrolled. There are several species of aphids that can infest strawberry plants, including Black bean aphid (Aphis fabae), Cotton aphid (Aphis gossypii), Glasshouse potato aphid (Aulacorthum solani), Strawberry aphid (Chaetosiphon fragaefolii), Potato aphid (Macrosiphum euphorbiae), Peach potato aphid or Tobacco aphid (Myzus persicae) and Yellow rose aphid (Rhodobium porosum). These aphids feed on the sap of strawberry plants, extracting vital nutrients and weakening the plant's overall health. They reproduce rapidly, leading to population explosions if not managed promptly. The presence of aphids can cause distorted growth, curling leaves, stunted development, and the development of honeydew, a sticky substance that attracts ants and is a substrate for the growth of sooty mould.

Fruit flies

Fruit flies, particularly the species Spotted Wing Drosophila (Drosophila suzukii), pose a significant threat to strawberry crops. These tiny insects have a preference for ripe, soft fruits, making strawberries a prime target. The female fruit flies lay their eggs below the surface of the berries, and the hatched larvae feed on the fruit, causing damage and rendering it unmarketable. The infestation by Drosophila suzukii can lead to reduced fruit quality and severe economic losses.

Caterpillars

Caterpillars can pose a significant threat to strawberry crops, with certain species causing notable damage to the plants and fruits. Two such species that are known to affect strawberries are Tomato looper (Chrysodeixis chalcites) and Southern European marshland pyralid (Duponchelia fovealis). These caterpillars have voracious appetites and feed on the leaves, stems and fruits of strawberry plants, causing defoliation, fruit deformities and yield loss. Southern European marshland pyralid (Duponchelia fovealis) is known to burrow into the fruit, causing internal damage and making the berries unsuitable for consumption.

Plant bugs

Plant bugs, particularly those belonging to the genus Lygus, can pose a significant threat to strawberry crops. These bugs, commonly known as tarnished plant bugs or capsid bugs, are piercing-sucking insects that feed on the foliage, flowers and developing fruits of strawberry plants. Their feeding activity can cause various types of damage, including stippling, distortion and discoloration of leaves, as well as blemishes and deformities on the fruits. Additionally, their feeding can also result in reduced fruit size and yield.

Plant parasitic nematodes

Plant parasitic nematodes can be a significant concern in strawberry crops, as they can cause damage to the roots and negatively impact plant growth and yield. Several species of nematodes, such as root-knot nematodes (Meloidogyne spp.) and lesion nematodes (Pratylenchus spp.), can infest strawberry plants and feed on their root tissues. As a result, infected plants may exhibit stunted growth, reduced vigour and nutrient deficiencies. The nematodes' feeding activity can also create entry points for secondary infections by fungi and bacteria, further compromising plant health.

Spider mites

Spider mites, particularly the species Two-spotted spider mite (Tetranychus urticae), and to a lesser extent, European red mite (Panonychus ulmi), can be a significant concern in strawberry crops. These tiny arachnids are known for their ability to reproduce rapidly and inflict damage to the plants. Spider mites feed on the strawberry leaves by piercing the plant cells and extracting the sap, leading to the characteristic stippling or yellowing of the foliage. As their populations grow, they can cause severe leaf damage, reduce photosynthesis, and impact fruit quality and yield.

Other pest mites

Other pest mites can also be a significant concern in strawberry crops, with certain species causing damage to the plants, affecting their overall health and productivity. One of the species that is known to infest strawberries is Phytonemus pallidus, commonly known as the Strawberry mite, or Cyclamen mite. These mites are tiny arthropods that feed on the leaves and buds of strawberry plants. The mites can cause characteristic symptoms such as yellowing and curling of leaves, stunted growth and deformation of fruits. Their feeding activities can weaken the plants, making them more susceptible to other pests and diseases.

Thrips

Thrips pose a significant threat to strawberry crops, with species such as Western flower thrips (Frankliniella occidentalis), Rose thrips (Thrips fuscipennis), and Onion thrips (Thrips tabaci) being particularly common. These tiny insects feed on various plant parts, including the leaves, flowers and developing fruits. Thrips cause damage by piercing the plant tissues and extracting sap, leading to distorted growth, silvering of the leaves, and scarring on the fruits. Moreover, they can transmit viral diseases, further impacting plant health and productivity.

Beetles

Several beetles can pose a threat to strawberry crops. Weevils, including species like Strawberry blossom weevil (Anthonomus rubi) and (Otiorhynchus spp.), can pose significant challenges to strawberry crops. Strawberry blossom weevil (Anthonomus rubi) is a notorious pest that specifically targets strawberry flowers. The adult weevils feed on the flower buds, causing damage and reducing fruit production. Otiorhynchus sulcatus, commonly referred to as black vine weevils, are generalist pests, the adults of which feed on the foliage of strawberry plants, and larvae on the roots. Their feeding activity can weaken the plants and result in stunted growth.

Other species of concern are Hylamorpha elegans and Common cockchafer (Melolontha melolontha). These beetles can feed on various parts of the strawberry plant, including leaves, flowers, and fruits, leading to significant economic losses. Their feeding activity can result in defoliation, flower destruction, and fruit damage, affecting both the quantity and quality of the harvest.

Whitefly

Whiteflies, including species such as Tobacco whitefly (Bemisia tabaci) and Greenhouse whitefly (Trialeurodes vaporariorum), are common pests that can affect strawberry crops. Tobacco whitefly (Bemisia tabaci) is a notorious pest that feeds on the undersides of strawberry leaves, sucking plant sap and causing yellowing, wilting, and stunted growth. Additionally, it can transmit various viral diseases to the plants. Greenhouse whitefly (Trialeurodes vaporariorum) is another species that can infest strawberry crops. They cause similar damage by feeding on plant sap and excreting honeydew, which promotes the growth of sooty mould and reduces the plant's ability to photosynthesise effectively.

Biological pest control is widely used in strawberry crops as part of a grower's IPM strategy. Various beneficial organisms are employed to regulate pest populations naturally and reduce reliance on chemical pesticides. In strawberry production, biological control agents such as predatory mites, lacewing larvae and parasitic wasps, are commonly used to target pests like aphids, thrips and spider mites. These natural enemies prey on or parasitise the pests, helping to keep their populations in check. By implementing biological control methods, strawberry growers can achieve effective pest management while minimising the environmental impact and promoting sustainable agricultural practices.

Aphid control

Biological pest control is an effective approach to manage aphid infestations in strawberry crops. Several beneficial organisms are utilised as biocontrol agents to suppress aphid populations. The larval stages of the gall midge Aphidoletes aphidimyza (Aphidend) feed on aphids, providing efficient control. Parasitic wasps, including Aphelinus abdominalis (Aphilin), Aphidius colemani (Aphipar), Aphidius matricariae (Aphipar-M), Aphidius ervi (Ervipar), Praon volucre and Ephedrus cerasicola (Aphiscout), parasitise and control aphid populations by laying eggs inside aphids. Chrysoperla carnea (Chrysopa, Chrysopa-E), commonly known as the green lacewing, is another beneficial insect that feeds on aphids at various life stages. The entomopathogenic fungus Akanthomyces muscarius (formerly called Lecanicillium muscarium) (Mycotal) infects and kills aphids, contributing to population reduction.

These biocontrol agents contribute to the biological pest control of aphids in strawberry crops, reducing the need for chemical pesticides and promoting sustainable farming practices.

Caterpillar control

The use of beneficial nematodes, including Steinernema feltiae (Entonem) and Steinernema carpocapsae (Capsanem), has proven to be successful in controlling caterpillar populations. These nematodes are entomopathogenic, meaning they infect and kill the caterpillars. Once applied, the nematodes actively seek out the caterpillar larvae, penetrate their bodies, and release bacteria that quickly multiply, leading to the demise of the pests. Beneficial nematodes are highly effective in controlling caterpillar populations due to their unique biological characteristics. This method of biological control is highly targeted, as the nematodes specifically seek out caterpillar hosts, making them efficient and environmentally friendly agents in reducing caterpillar populations.

Beetle control

Biological pest control of beetles in strawberry crops can be achieved through the use of beneficial nematodes as biocontrol agents. Specifically, Steinernema feltiae (Entonem) and Heterorhabditis bacteriophora (Larvanem) are effective in managing these pests. These entomopathogenic nematodes have the ability to seek out and infect the larvae, or grubs, of beetles and weevils in growing medium. Once inside the host, the nematodes release bacteria that will kill the pest.

Mite control

Biological pest control of pest mites in strawberry crops can be achieved through the use of beneficial predatory mites. Common biocontrol agents employed in this regard are Neoseiulus cucumeris (Thripex, Thripex-Plus), Amblyseius andersoni (Anso-Mite, Anso-Mite Plus) and Transeius montdorensis (Montdo-Mite, Montdo-Mite Plus). At higher temperatures Amblyseius swirskii (Swirski-Mite) can also be used. These predatory mites are natural enemies of pest mites and play a crucial role in regulating their populations. Amblyseius andersoni and Transeius montdorensis are well-known for their ability to adapt to different environmental conditions and effectively control mite infestations in strawberry crops.

Spider mite control

Biological pest control of spider mites in strawberry crops can be achieved effectively through the use of beneficial predatory organisms. Several biocontrol agents have shown efficacy in controlling spider mite populations. Neoseiulus californicus (Spical, Spical-Plus, Spical Ulti-Mite) and Phytoseiulus persimilis (Spidex, Spidex Vital, Spidex Vital Plus) are predatory mites that target and feed on spider mites, including species like Two-spotted spider mite (Tetranychus urticae). These predatory mites actively seek out spider mite colonies and consume them, helping to reduce their numbers and prevent further damage to the strawberry plants. Additionally, Feltiella acarisuga (Spidend), a predatory gall midge, is known for its ability to feed on spider mite eggs and young larvae.

Thrips control

Biological pest control of thrips in strawberry crops can be achieved effectively through the use of various biocontrol agents. Predatory mites such as Amblyseius swirskii (Swirski-Mite, Swirski-Mite LD, Swirski-Mite Plus, Swirski Ulti-Mite), Amblyseius andersoni (Anso-Mite, Anso-Mite Plus), Transeius montdorensis (Montdo-Mite, Montdo-Mite Plus), Amblydromalus limonicus (Limonica) and Neoseiulus cucumeris (Thripex, Thripex-Plus, Thripex-V) are valuable allies in thrips management, as they feed on thrips eggs and larvae. Other beneficial mites, Stratiolaelaps scimitus (Entomite-M) and Macrocheles robustulus (Macro-Mite), prey on thrips pupae in the soil, contributing to population control. Akanthomyces muscarius (Mycotal) a fungal pathogen, can be applied to target thrips populations and inhibit their growth. For additional control, predatory bugs such as Orius insidiosus (Thripor-I) and Orius laevigatus (Thripor-L) can be introduced, as they feed on thrips at different stages of development. Lastly, Steinernema feltiae (Capirel, Entonem), a beneficial nematode, can be applied to the growing medium to target thrips larvae and pupae.

Whitefly control

Biological pest control of whiteflies in strawberry crops can be achieved through the use of various biocontrol agents. Akanthomyces muscarius (Mycotal), a fungal pathogen, can be applied to target whitefly populations and disrupt their development. Encarsia formosa (En-Strip) and Eretmocerus eremicus (Ercal, Enermix) are parasitic wasps that parasitise whitefly nymphs, effectively controlling their population. Amblydromalus limonicus (Limonica) and Amblyseius swirskii (Swirski-Mite, Swirski-Mite LD, Swirski-Mite Plus, Swirski Ulti-Mite) are predatory mites that feed on whitefly eggs and nymphs, providing long-term suppression.

Pest monitoring plays a crucial role in the successful management of pests in strawberry crops. By regularly scouting the field, growers can identify the presence and abundance of pest populations, enabling them to take timely and targeted action. Various monitoring techniques are employed, including visual inspections and trapping systems.

Visual inspections involve observing the plants for any signs of pest damage or the presence of pests themselves. Trapping systems, such as sticky traps (Horiver, Rollertrap) or insect traps, can be used to attract and capture specific pests, providing valuable information about their population dynamics.

Scouting involves systematically examining the crop, noting pest infestations, and recording relevant data (Natutec Scout). By consistently monitoring the pest activity, growers can make informed decisions regarding the implementation of pest control strategies, optimising the use of resources, and minimising the risk of crop damage.

Additionally, pest scouting allows for the early detection of emerging pests, facilitating prompt intervention and preventing potential outbreaks. Overall, regular and thorough pest monitoring is an essential component of IPM in strawberry production, helping growers maintain healthy crops and achieve optimal yields.

Strawberry crops are susceptible to various diseases that can significantly impact their health and productivity.

Bacterial diseases

Bacterial diseases, caused by pathogens such as Xanthomonas fragariae and Pseudomonas spp., can lead to leaf spotting, crown rot and fruit rot.

Botrytis

Botrytis, caused by the fungus Botrytis cinerea, is a common fungal disease that causes grey mould, leading to decay and rotting of flowers, fruits and foliage.

Downy mildew

Downy mildew, caused by the oomycete pathogen Peronospora sparsa, results in purple-brown lesions on leaves and white fluffy growth on the undersides.

Fusarium

Fusarium, caused by various Fusarium species, causes wilting, stunting and root rot in strawberry plants.

Phytophthora

Phytophthora, caused by the oomycete Phytophthora cactorum, leads to crown and root rot, causing plants to decline and die.

Powdery mildew

Powdery mildew, which can be caused by several fungi, such as Podosphaera aphanis, results in a white powdery coating on leaves, reducing photosynthesis and weakening plants.

Pythium

Pythium, caused by Pythium spp., causes damping-off, root rot and crown rot in strawberry seedlings and young plants.

Effective disease management strategies, including proper sanitation, crop rotation, resistant cultivars, and the use of fungicides when necessary, are crucial for controlling these diseases and maintaining the health and productivity of strawberry crops.

The biofungicides Trianum-G and Trianum-P, based on the antagonistic fungus Trichoderma harzianum T-22 protect the plants against various fungal diseases such as Pythium spp. and Fusarium spp. Nopath, a product based on essential oils can be used to control fungal diseases such as Pythium spp., Fusarium spp., Phytophthora spp.

Bumblebees play a vital role in the natural pollination of strawberry crops, ensuring optimal fruit set and yield. When bumblebees visit strawberry flowers to collect nectar and pollen, they inadvertently transfer pollen between the male and female flower parts, enabling fertilisation and fruit development. This efficient pollination process leads to larger, more uniform berries.

Bumblebees for strawberry pollination

Bumblebees play a crucial role as pollinators in strawberry crops due to their unique characteristics. Their large size enables them to transfer pollen effectively from the anthers to the stigma of strawberry flowers, increasing the likelihood of successful fertilisation and fruit development.

One key attribute of bumblebees is their ability to perform buzz pollination. By rapidly vibrating their flight muscles, they dislodge pollen that is firmly attached to the flower's anthers, facilitating its release and subsequent transfer. This specialised techanique is particularly important for strawberries, as their pollen requires this buzzing action to be released.

Another advantage of bumblebees is their activity as pollinators in cooler temperatures and under cloudy conditions, when other bees may be less active. Their flexibility allows for consistent pollination throughout the strawberry flowering period, ensuring optimal fruit development even in less favourable weather conditions.

Furthermore, bumblebees exhibit flower constancy, meaning they tend to focus on one type of flower at a time before moving on to another plant species. This behaviour enhances the chances of cross-pollination between different strawberry plants, promoting genetic diversity and potentially improving fruit quality.

Overall, the combination of their size, buzz pollination ability, activity in cooler conditions, and flower constancy makes bumblebees highly effective pollinators for strawberry crops. Their presence and pollination services significantly contribute to maximising fruit set, yield and overall crop productivity.