Tomato Pests and Diseases

With the arrival of heat, the first problems with our plants begin to emerge. Specifically with tomatoes, there is a wide range of pests and diseases that can significantly influence our cultivation. Here we name the main problems that we are going to encounter and the possible treatments.


Let’s see the main pests and diseases of tomato  that we can find in our crops.



They are small adults, with shades that fluctuate from yellow to green, or yellow to red. The spider mite sucks up plant material, absorbing cellular juices as part of its diet. The affected tissue stains a yellowish color that becomes necrotic over time. In advanced pests, a characteristic spider web is generated around the entire plant.


It is a greenish caterpillar with a cylindrical body, with a size that ranges between 3 and 5 cm. Damage to the tomato plant is caused by bites from the larvae, on the leaves or on the fruits in the formation stage, leaving concavities, generally near the peduncle.


The female whitefly lays her eggs on the underside of the pepper leaves. Visible white spheres appear. For its food, it sucks the plant, weakening it and causing general wilting over time.


The galleries formed by this pest can be seen with the naked eye in the upper part of the leaf. The adult is 2 mm in size, black and yellow in color and has light-colored wings. The damage that occurs on the tomato plant originates when the adult bites on the leaf to deposit the eggs or to feed. The galleries that form become necrotic over time, weakening the plant.


This lepidopteran has a great reproductive capacity, producing between 40 – 50 eggs during its life cycle, without presenting a winter break. The damage that occurs in the tomato plant originates when the larvae penetrate leaves, stems or fruits to feed, causing galleries that necrotize over time.


Thrips are elongated insects that measure about 1-2 mm (they are visible to the eye and recognizable with a magnifying glass) and have a brown color. These insects suck the plant material from the tomato plant. The area where it has been suctioned shows a silver color and with time necrotism.



This disease caused by a fungus attacks the aerial part of the plant in conditions of high humidity (90%). Detection of the presence of the fungus is due to the appearance of irregular spots that over time necrotize on the leaves. Brown spots appear on the stem, and brown spots with irregular contours appear on the fruit.


This fungus manifests itself on the tomato plant with a whitish mycelium visible to the naked eye. The germination temperature of the fungus fluctuates between 10ºC and 35ºC, with optimum temperatures below 30ºC.

Powdery mildew


On leaves, stems and flowers there are brown spots (grayish powder) which is the gray mycelium of the fungus. A soft – watery rot occurs in the fruits.


This common tomato disease only affects the leaves in high humidity conditions (above 70%). To locate this disease, you must see a yellow-brown spot on the underside of the leaves.

The most effective remedy is prevention, acting at the first outbreaks that appear on the leaves of the tomato plant, avoid stagnant or free water that may remain on the leaves.


Anthracnose appears in tomatoes when the fruits are in the ripening process. On them appear circular spots of watery appearance (like rotten) that sink inwards. The center becomes even darker over time and rot increases.


Virus of the genus Tobamovirus distributed throughout the width of the planet and that attacks other species of the Solanaceae family .

The most peculiar symptom is the appearance of chlorotic spots on the fruit and mosaic-shaped leaves (hence the name of the virus). Such chlorosis has no resemblance to nutrient deficiencies .

To know the treatments applicable to these tomato pests and diseases, you can use the following application of the Ministry of Agriculture of Spain:

Registration of phytosanitary products

Simply in the scope of application you choose crops , in the crop you select tomato , and in the pest / effect you choose one of the detected pests or diseases. You will get the active subjects that can legally be applied.

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