Tomato Pests and Diseases: Complete Guide with Photos and Tips

Hello to all gardeners! In today’s article we will talk about tomato pests and diseases . We are going to start with a series of articles that summarize the diseases and pests that can affect the different crops in the garden and later we will talk about each one of them and how to treat them. Let’s start with the tomato!

Tomato pests

Tomato absolute tuta

Tuta ( Tuta absolu ) : The symptoms caused by this lepidopteran are wide mines that leave the epidermis intact but remains of excrement can be seen inside. The shoots are moth-eaten and the tomatoes have holes and blackened internal areas.

Tomato caterpillars

Tomato worm ( Heliotis sp .) And other caterpillars ( Helicoverpa spp ., Spodoptera spp., Autographa gamma, etc. ):  We find some holes of considerable size where, sometimes, we can see the caterpillar eating our fruit. You can also see gnawing on leaves, flowers, fruits and tender shoots, usually with excrement and WITHOUT SLUGS (it gives us the clue that it is not a snail or slug)

Aphids on tomato leaves

Aphids (Myzus persicae, Macrosiphum euphorbiae, Aulacorthum solani… ): Aphids produce a downward curling and wrinkling of leaves. In addition, you can see colonies of these small dark or greenish insects, especially on the tender shoots of the developing plant. Another clue is the presence of molasses (sugary and sticky substance) and ants around them defending them.

Whitefly on tomato

Whitefly ( Trialeurodes vaporarium, Bermisia tabaci ): We can see some white flies (which are not really flies) with a characteristic erratic flight when shaking the plant. In addition, like aphids, they release molasses. They are usually arranged on the underside of the leaves.

Red spider on tomato

Spider mite (Tetranychus urticae): The spider mite is a mite that leaves the leaves discolored with small stippling and silks. If it affects significantly, it can cause desiccation and defoliation of the plant.

White spider on tomato

White spider (Polyphagotarsonemus latus): This mite leaves bulging, curved, darker leaves with an elongated appearance and protruding veins.

Tomato vasates

Vasates (Aculops lycopersici): the leaves of the tomato plant gradually  dry up, taking on pinkish colors and the stem gradually turns tan until they are both dry with a reddish-yellow color due to this mite.

Liriomyza or tomato miner fly

Miner fly (Liriomiza spp.) :  Makes clear and sinuous galleries in the leaves.

Tomato flower thrips

Flower thrips (Frankliniella occidentalis) :  Damaged plants have leaves with small, irregular silver spots, corresponding to lesions on the underside.

Tomato Diseases

Downy mildew (Phytophtora infestans):  Initially, the leaves of the plant show yellowish spots with an oily appearance that turn brown, the center becoming necrotic.

A thin white veil appears on the underside that corresponds to the spores. On the stem, we find elongated brown spots that symbolize necrosis and wilting in the plant. The crop takes on a burnt appearance. On the developing fruits, soft spots with a brown appearance are generally observed in the upper half.

Tomato powdery mildew

Oidiopsis ( Leveillula taurica, Phytophtora capsici, Alternaria solana ):  We find yellowish spots on the upper part of the leaf that quickly necrotize and a kind of whitish powder appears on the underside.

Tomato alternariosis

Alternariosis ( Alternaria solana ):  On the lower leaves we find circular brown spots in concentric rings. On stems and petioles the spots are black and well defined. In fruits, there is a depressed necrosis covered with a black mold.

Root and stem of rotten tomatoes

Neck and root rot (Phytophtora spp. Pythium sp., Rhizoctonia solani, Sclerotinia sp. Etc.):  Young plants wither, presenting strangulation and rotting in the neck (the lowest area of ​​the stem that adjoins the substrate).

Vascular fusariosis 

Vascular fusariosis (Fusarium oxysporum sp. Lycopersici) :  Wilting and flaccidity of the upper leaves, pronounced in hot hours. A progressive yellowing and necrosis of the leaves is observed from the bottom up, observing the green nerves.

Bacterial black spots

Bacterial black spot (Pseudomonas syringae pv. Tomato) :  In all the aerial organs of small tomato plants we find black spots with an irregular outline. On the leaves, the spots have a yellow halo and can even dry them out. On tomatoes we find small black pustules often with a lighter «eye» in the center.

Nematodes

Nematodes (Meloidogyne spp.):  Plants infected by nematodes show weak growth, wilting, chlorosis, and roots with deformations and galls (nodules). Distribution in stands (plants forming more or less circular areas) or following irrigation lines.

Tomato virus

Viruses: Mosaics in leaves, dwarfism, chlorotic rings (yellow), curling and curling of leaves, deformations of fruits with wavy spots or rings …

Common Physiopathies in Tomato and Pepper

The physiological disorders are diseases caused by abiotic factors , ie, there is no causative pathogen but it fosters a bad condition in the middle as deficiencies or excesses of nutrients, low or high temperatures, drought and mismanagement of irrigation and salinity , among others .

Rotten Tomato Asses

Necrosis or apical rot of fruits («Rotten or shitted asses») :  A depressed black spot appears at the base of the tomato, usually round.

Grilled or ironed tomato

Isolated or pressed fruits:  A depressed white area appears on the side of the fruits exposed to the sun, leaving the tissue with a papery appearance and, if the fruit is still young, then a scar is formed.

Cracked or cracked tomato

Cracked or cracked fruit:   Appearance of longitudinal or concentric cracks around the area of ​​the peduncle of the fruit that can take on the appearance of cork.

Tomato leaf curl

Leaf curl: Tomato plants curl  up the leaflets of their leaves, giving the plant a curled appearance.