El tomato crop It is threatened by various pests, but among the most destructive are red spider y the caterpillarsTheir rapid proliferation and the damage they cause can compromise profitability and the quality of the final product. Therefore, thoroughly understanding their impact, learning to recognize their symptoms, and applying appropriate control methods is essential for producers of any size.
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What is a red spider mite on tomatoes and how to recognize it?
La Red spider (Tetranychus urticae) is a small mite very polyphagous It barely measures half a millimeter. Its color varies from green to reddish, depending on environmental factors, and it has two dark spots on its sides. This mite reproduces rapidly, completing its life cycle in less than 15 days under optimal conditions, so it can quickly become a pest.
The conditions that most favor the proliferation of red spider in tomatoes are low relative humidity (less than 50%) and high temperatures (around 30°C or more). The egg-to-adult cycle is considerably accelerated in this environment, allowing for several generations in a single season.
Direct and indirect damage from red spider mites in tomatoes
The first visible sign of infestation is the presence of fine cobwebs on the underside and upper surface of the leaves. The most notable damage includes:
- Yellow dotted on the leaves, caused by sap suction.
- Reduction of photosynthesis by limiting the active leaf surface.
- Premature fall of leaves and fruits, affecting overall performance.
These injuries can lead to production losses of up to 80%. Furthermore, small wounds in the tissues become entry doors for fungi and viruses, making crop management even more difficult.
How to combat red spider mites in tomatoes?
Precautionary measures
The first step to controlling the red spider is to adopt a preventive strategy and rigorous monitoring:
- keep moderate relative humidity In greenhouses, increasing the frequency of watering or using nebulizers if possible.
- Avoid water stress and keep plants well watered according to the needs of the variety.
- Delete weeds and plant remains that can serve as a refuge or reservoir.
- Periodic revision of leaves to detect the first outbreaks.
- Rotate crops and alternate with species that are not hosts of this mite.
Biologic control
El biologic control It allows for a reduction in the use of chemicals and the preservation of beneficial natural enemies. The most effective predators are:
- Phytoseiulus persimilis: excellent for controlling initial outbreaks.
- Amblyseius californicus y Neoseiulus californicus: adapted to variable temperature conditions, ideal for greenhouses and outdoors.
- Feltiella acarisuga: its larva consumes large quantities of red spider.
- Stethorus punctillum: small predatory beetle.
- Amblyseius andersoni: effective in cooler climates.
Rational chemical control
If biological methods have not been sufficient, one can resort to specific phytosanitary productsIt is essential to always follow official recommendations:
- Use selective acaricides and apply them only in the affected areas to avoid eliminating useful fauna.
- Use oils, sulfur (if temperature permits), or approved contact products. Wet leaves, stems, and fruit thoroughly.
- Avoid continued use of broad-spectrum insecticides.
- Regularly consult the national registry of phytosanitary products to see authorized and current alternatives.
Caterpillars as a key pest in tomato: species and damage
Others lepidoptera (butterflies) affect tomatoes in their larval stages, acting as fundamental pests:
- Helicoverpa armigera (tomato borer), whose Larvae especially attack developing fruits, leaving perforations on the surface and promoting fungal and bacterial infections.
- Tuta absoluta (tomato moth): generates mine galleries in leaves, stems and fruitsDamage can appear at any stage of the crop and is particularly severe in greenhouses.
- Spodoptera exigua (green donut) and Spodoptera littoralis (black ring): They devour leaves and can cause intense defoliation in young shoots.
- Agrotis spp. (gray worms): attack the neck of the plant and roots, causing breaking and death in young plants.
In severe infestations, caterpillars can destroy the entire foliage, drastically reduce photosynthetic capacity and expose the fruits to sunburn or secondary damage.
Symptoms and diagnosis of caterpillar and spider mite pests
- Leaf with elongated galleries, dark spots or presence of excrement: indicates an attack of Tuta absoluta.
- Fruits with holes or obvious scars, often with visible presence of larvae.
- Drying and premature fall of leaves (in the presence of abundant web): typical symptom of red spider.
- Yellow dotted and progressive wilting.
- In the case of ground caterpillars, clean cut at the base of the stem, especially in young seedlings.
Integrated pest management strategies
Prevention and cultural management
- Use certified and pathogen-free seeds.
- Remove remains of affected plants and weeds that serve as a refuge.
- Implement crop rotations and avoid planting tomatoes several seasons in a row.
- Regularly inspect the crop, especially the edges of plots and areas near greenhouses.
- Avoid overwatering or flooding, which facilitates other pests and diseases.
Biological and physical control
- Use natural predators of red spider and caterpillar parasites (such as Trichogramma spp.)
- Installation of chromatic traps to monitor and control adult butterflies and whiteflies.
- Manual collection of caterpillars in initial infestation outbreaks, in small crops or urban gardens.
- Placement of light traps and pheromone traps for Tuta absoluta and Heliothis adults.
Chemical control in integrated management
- Apply phytosanitary products registered and authorized only when the pest population exceeds tolerable economic limits.
- Alternate active ingredients to avoid resistance.
- Use Bacillus thuringiensis as a biological insecticide against young caterpillars.
- Consult the updated registry of phytosanitary products on the official website of the Ministry of Agriculture and follow the specific recommendations based on the problem.
Other relevant pests in tomato cultivation
- Aphids: Aulacorthum solani, Macrosiphum euphorbiae, Myzus persicae, Aphis gossypiiThey transmit viruses and cause deformations in young leaves.
- White flies: Trialeurodes vaporariorum, Bemisia tabaci. Sap extraction and transmission of viruses such as tomato leaf scoop virus (TYLCV).
- Trips: Frankliniella occidentalisThey cause damage to leaves and fruits and are vectors of serious viruses.
- Leaf miners: Liriomyza bryoniae, Liriomyza huidobrensis, Liriomyza trifoliiThe larvae create mines inside the leaf that weaken the plant.
- Mealybugs: Pseudococcus viburniThey form colonies on stems and leaves, weakening the plant and facilitating the appearance of sooty mold.
- Eriophyid mites such as vasate (Aculops lycopersici): browning and dieback of the plant.
Good monitoring and recording practices
Wear a detailed log of all tasks, applications and treatments is vital to evaluate the effectiveness and prevent future infestations. Applications and platforms such as tomato pests treatment facilitate this monitoring.
Key recommendations for maintaining a healthy crop
- Apply integrated control practices, combining cultural, biological and chemical methods.
- Maintain constant vigilance and act at the first symptom.
- Always select appropriate authorized products and respect safety deadlines.
- Prioritize the use of resistant varieties when available.
- Keep the plantation clean and carry out adequate rotations.
Thanks to the implementation of these strategies and timely identification, it is possible reduce the impact of the Red spider and the caterpillars on tomato crops, ensuring quality harvests and more sustainable management.
