Black lice and flies on tomato plants indicate a pest infestation. We present the most common tomato pests and show you how to combat aphids, fungus gnats and the like on tomatoes naturally.
Tomatoes are not only very popular with many gardeners, but unfortunately also with some pests. We will show you which pests commonly attack tomatoes and how you can get rid of them efficiently and naturally.
Control tomato pests
A whole range of pests can affect tomatoes. Not only can the plant be weakened, but the fruits can quickly look ugly or lose quality. It is therefore important to discover the malware as quickly as possible and to determine which culprit it is.
Aphids on tomatoes
As soon as the tomato plant takes shape in early summer, the first aphids (Aphidoidea) can often be seen. The insects, which are a few millimeters in size and mostly green or black in color, are mainly found on the tips of the shoots. The little pests pierce the phloem, certain pathways in the plant, and suck on the sugary plant sap. This weakens the plant, and the sucking activity and saliva of the lice often result in deformation of the leaves. Another sign that a tomato has been infested with lice is shiny spots or plaque on the leaves. This is honeydew, the sugary excretions of the aphids. Black fungi can form on these deposits, which are also easily recognizable in the case of an advanced infestation. These fungi impede photosynthesis, further weakening the plant. Ants are also interested in honeydew, which is why an increased occurrence of ants on a tomato plant can be an indication of an aphid infestation. In addition, the aphids can transmit viruses from one plant to another and thus damage the tomato plant.
Tip: Aphids reproduce rapidly. Per weekthe number can increase by a factor of about 10. If you recognize an infestation, you should act promptly to avoid mass propagation.
Control of aphids on tomatoes
In the case of a slight aphid infestation on tomatoes, home remedies can be used. Soapsuds or nettle broth are suitable for this, as we describe in detail in our special article on home remedies for aphids. If you don't want to bother using a home remedy or if the infestation is more severe, we recommend a biological pesticide. Synthetic agents are very dangerous to beneficial insects, which is why we advise against using these agents.
Biological agents based on neem oil are particularly effective. This oil from the seeds of the neem tree allows you to get rid of aphids naturally. Our Plantura organic pest-free neem is based on this effective oil from the neem tree. The agent is purely herbal and can be used both outdoors and in tomato cultivation in the greenhouse. The active ingredient is absorbed by the plant and allows you to catch hidden aphids. Further damage is prevented by the suction stop that occurs quickly. At the same time, our organic pest-free neem is not dangerous to bees.To treat an area of ten square meters with tomatoes, simply mix two milliliters of Organic Pest Free Neem with 600 milliliters of water. You can then spray this emulsion on the affected plants. After treating your tomatoes with organic pest-free neem, there is a waiting period of three days during which you should not harvest or eat any fruit. After this time, the active ingredient has been broken down to such an extent that you can eat the fruit with pleasure. Please use our organic pest-free neem according to the specifications in the application recommendation. Before use, you should read the package leaflet carefully.
Further biological agents based on rapeseed oil are also commercially available. Unfortunately, these have to be applied more frequently because of their lower effectiveness, which harms some plants. Another possibility is the use of beneficial insects. Ichneumon wasps, lacewings or ladybird larvae can be used against aphids. The use is particularly effective in a greenhouse or similar closed space. However, please note that beneficial insects cannot be used in combination with pesticides.
You can prevent beneficial insects in your garden with a natural garden design, such as a flower meadow that is as untouched as possible. Our Plantura beneficial insect magnet is a seed mixture that allows you to create such a flower meadow. When fertilizing your tomatoes, you should also ensure a good supply of potassium and reduced nitrogen fertilization. This makes your tomatoes less susceptible to aphids. For fertilizing, we recommend special tomato fertilizers that are tailored to the needs of your tomatoes, such as our Plantura organic tomato fertilizer.
We have put together more tips on how to combat aphids naturally in our special article.
Summary: Controlling and Preventing Aphids on Tomatoes
- In the case of a slight infestation, household remedies such as soapy water or nettle brew are possible
- Organic pesticides such as our Plantura organic pest-free neem or agents based on rapeseed oil
- Beneficial insects such as parasitic wasps and ladybird larvae, especially in sheltered cultivation
- Promote preventive beneficial insects in the garden
- Make plants more resilient through need-based fertilization
Black Flies on Tomatoes
Do you often see small black flies on the potting soil of your tomatoes? Then it is most likely fungus gnats (Sciaridae). If small flies are only on the leaves of your tomatoes, it is certainly an infestation by thrips (Thysanoptera). Below we will show you how to combat fungus gnats or thrips on tomatoes.
Control fungus gnats on tomatoes
The best way to tell if your tomatoes are infested with fungus gnats is by the tumbling, black, adult flies. Yellow panels can be used to identify an infestation as early as possible. These are covered with glue and attract the fungus gnats. The insects stick to the panels and enable you to recognize an infestation early on. Yellow boards can also be used preventively, but they are not enough to combat a real infestation.
Blackfly larvae live in the potting soil, feeding on organic matter, including tomato roots. This can damage your plants and lead to wilted leaves and poor growth in the long term.
If you use theIf you recognize an infestation at an early stage, you can use a home remedy. In our special article on fighting fungus gnats with home remedies, we show you how you can get rid of flies with garlic, for example. In Germany, no chemical or natural spray is currently approved for treating fungus gnats on tomatoes. If the infestation is advanced or if there is no effect, we recommend that you act quickly and use beneficial insects, for example. The predatory nematodes Steinernema feltiae e.g. can be used specifically against infestations by fungus gnats. The success is visible after a few days. Another useful against fungus gnats is the predatory mite Macrocheles robustulus, which can be used in protected cultivation. In the case of a severe infestation, it can also be helpful to repot the plant and wash out the root ball with water. This will get rid of much of the infested soil. The plant is then repotted.
Fungus gnats only thrive in permanently moist soil. As a preventive measure, we therefore recommend that you avoid waterlogging. It is also very effective to spread a 1/2 inch layer of sand, grit or expanded clay over the potting soil to keep the surface dry, which also helps preventively. This is the best way to protect all potted plants in the vicinity.
Summary: Controlling and Preventing Fungus Gnats on Tomatoes
- Yellow panels to identify an infestation at an early stage
- In the case of a mild infestation: use home remedies such as garlic
- No chemical or natural pesticides allowed on tomatoes against fungus gnats
- Beneficial insects such as the predatory nematode Steinernema feltiae or the predatory mite Macrocheles robustulus work very well when used correctly
- In the case of a severe infestation, repot the plant and remove the old soil if possible
- Avoid permanently moist soil as a precaution and apply a thin layer of sand to the soil - this also protects other plants nearby
Control of thrips on tomatoes
Thrips (Thysanoptera) thrive in low humidity and constant temperatures - for example in living rooms. The insects themselves are so small that they can hardly be seen with the naked eye. An infestation is mainly due to the typical damage patternRecognize: Small yellow or silvery-grey speckles on leaves or flowers. If the infestation is more severe, these dots can become larger and the affected leaf can die off. You can also place blue panels near potentially infested plants. The color of these panels attracts the thrips, which get stuck on the glue. This allows you to identify an infestation early on.
Soapsuds with olive oil or putting the indoor plants out in the rain are smart home remedies that can help with a mild infestation. You can find out more about home remedies for thrips and how you can successfully combat thrips in our special article.
Also, as a biological method, beneficial insects can be used. The most effective way is to use the predatory mite (Amblyseius cucumeris) or the lacewing (Chrysoperla carnea) in the greenhouse. If you are unsuccessful or if mixing a household remedy is too time-consuming for you, we recommend a biological pesticide. Neem oil-based agents are particularly effective against thrips infestation. Our Plantura organic pest-free neem is also based on this highly effective oil and has already been presented above in connection with aphids.
As a preventative measure, we recommend that you ensure that the humidity in the rooms or in your greenhouse is kept stable and that it does not drop too much.
Summary: Controlling and Preventing Thrips on Tomatoes
- In the case of a mild infestation: household remedies such as soapy water with olive oil
- Beneficial insects such as the predatory mite (Amblyseius cucumeris) or the lacewing (Chrysoperla carnea) in the greenhouse
- Organic agents based on neem oil, such as our Plantura organic pest-free neem
- Prevent very low humidity levels
- Blue signs for early detection of infestation
Whiteflies on tomatoes
Whiteflies are different genera and species of whitefly (Aleyrodoidea). The cabbage whitefly (Aleurodes proletella) and the greenhouse whitefly (Trialeurodes vaporariorum) are particularly troublesome infestations here in Germany. This can be recognized by the small white insects on the underside of the leaf. There can also be small white eggs, oftenstored in a ring, to be discovered. When the plant is touched, the adult insects usually fly away in a small arc.
Control of whiteflies on tomatoes
A stinging nettle decoction is particularly suitable as a home remedy for a mild infestation. You can also use potash soap and treat the plant with it. If the infestation is severe or the home remedy is not working satisfactorily, we recommend using a biological pesticide as soon as possible. Our Plantura organic pest-free neem, which you have already got to know above in connection with aphids on tomatoes, can also be used effectively against whiteflies on tomatoes.
Other organic products based on orange or rapeseed oil are also available. These agents work on contact as they block the insects' oxygen supply, causing them to die. You can also buy ready-mixed potash soap products. In addition to these biological agents, you can also find agents based on acetamiprid and deltamethrin on the market, but both are too harmful to beneficial insects and the environment for us to recommend them.
Another possibility are beneficial insects that can be used against the whitefly. These include various species of parasitic wasps (Encarsia formosa), predatory bugs (Macrolophus pygmaeus) and predatory mites (Amblyseius swirskii). ). Such targeted use is particularly effective in closed rooms, such as in a greenhouse. You should make sure that you do not use beneficial insects in combination with a pesticide.
The whitefly can easily survive in the greenhouse even in cold winters. That is why prevention in the form of good hygiene in the greenhouse is important. You should not bring in affected plants, or isolate affected plants immediately. A constant draft is not well received by the whitefly - another reason why you should always ensure good ventilation in greenhouses.
In our special article we will show you detailed information on how to fight whiteflies naturally.
Summary: Control and Prevent Whitefly
- In the case of a mild infestation: home remedies such as nettle broth
- Especially in the case of a stronger infestation: biological agents such as our Plantura organic pest-free neem
- Beneficial insects such as parasitic wasps, assassin bugs andPredatory mites, especially possible in sheltered cultivation
- As a preventive measure in the greenhouse, make sure you don't put any infested plants in it
- Ensure good ventilation in the greenhouse
Spider mites on tomatoes
Spider mites (Tetranychidae) occur particularly in greenhouse cultivation. Chili and peppers are particularly susceptible to an infestation that can quickly spread to tomatoes. An infestation by spider mites on tomatoes can be recognized above all by the webs of the small eight-legged friends. These very fine webs can usually be recognized by branching or leaf styles. In the case of an advanced infestation, characteristic, punctiform brightening can be seen on the leaves.
Control of spider mites on tomatoes
There are many effective home remedies to combat spider mites: In the case of a light infestation, you can remove infested plant parts from plants that tolerate pruning. By hosing down the plant every day with a light spray of water, you will increase the humidity level for the spider mites, which will help get rid of them. You can enhance this effect by putting a transparent plastic bag over the plant. To prevent damage to the plant, we recommend carrying out this measure for a maximum of four days. We strictly advise against using a tobacco brew that is repeatedly mentioned in various guidebooks. Nicotine is a neurotoxin poisonous to humans and its use on plants has been a criminal offense in the EU since 2001.
The use of gall midges (Cecidomyiidae) or predatory mites (Gamasina) is one way to fight spider mites with beneficial insects. In particular, you can purchase the predatory mites Phytoseiulus persimilis or Amblyseius californicus on the Internet and use them selectively. However, if you have decided to use beneficial insects, you should refrain from using a pesticide, as this would harm the beneficial insects.
Spider mites can be very stubborn, which is why we recommend using a biological pesticide in the event of an advanced infestation. We advise against the use of synthetic pesticides, especially in the home garden, as these agents usually have a high potential for damage to beneficial insects. Spider mites are also already resistant to some synthetic active ingredients. Most biologicalCrop protection products against spider mites are based on rapeseed oil. The oil ensures that the pests die on direct contact. It is therefore important to wet the plant with the spray mixture on all affected areas. Several treatments are usually necessary for good effectiveness.
If you grow your tomatoes in a greenhouse, you can prevent the air in the greenhouse from becoming too dry. Spider mites thrive in dry air, so humidifying the air can help. We also recommend reduced nitrogen fertilization and a good supply of potassium to your plants. This makes your plants less attractive to spider mites. You can easily achieve this with a special tomato fertiliser, such as our Plantura organic tomato fertiliser.
We have put together a few more tips on recognising, preventing and fighting spider mites for you in our special article.
Summary: Controlling and Getting Rid of Spider Mites on Tomatoes
- If possible, remove heavily infested parts of the plant
- Flush infested plants daily with water
- Put plastic bag over infested plants for four days
- Targeted use of gall midges or predatory mites
- Biological pesticides based on rapeseed oil
- As a precaution, ensure that the air in the greenhouse is not too dry
- Reduced nitrogen fertilization and good potassium supply for your tomatoes
Tomato leaf miners
Tomato leaf miners (Tuta absoluta) have only been a pest in Germany for about ten years. The adult tomato miner moths are grey-brown in color and have a wingspan of up to one centimetre. The adult animals hide during the day, which is why they are usually difficult to find. The best way to recognize an infestation by the tomato leaf miner is to look at the damage done to the larvae: the larvae leave stain-shaped burrows in the leaves and sometimes also in the fruit when they eat. The caterpillars are permanently located in the leaf between the upper and lower skin of the leaf.
Control tomato leaf miners on tomatoes
In the commercial cultivation of tomatoes, the use of the assassin bug Macrolophus pygmaeus is the most common measure. However, the establishment of the assassin bug is not easy and quite time-consuming. A pesticide against the tomato leaf miner is not approved in Germany. We therefore recommend preventive measures to prevent a renewed infestation in the following yearimpede. An effective biological measure is to apply the nematode species Steinernema carpocapsae to the planting area with water before planting the tomatoes in spring. This is what we recommend when planting your tomatoes in established soil.
You should also avoid planting tomatoes in the same spot for several years in a row. If you plant the tomatoes in pots, you should not use the soil again to grow tomatoes. And the optimal supply of nutrients, for example with our Plantura organic tomato fertilizer, makes the plants he althy and enables them to effectively form defenses against the tomato leaf miner and other pests.
Summary: Controlling and Preventing Tomato Leaf Leafhoppers
- Assassin bug Macrolophus pygmaeus can be used, but establishment is complicated
- Nematode Steinernema carpocapsae as a preventive measure on established soil
- No pesticides allowed
- Do not reuse potting soil when cultivating in a pot, do not plant tomatoes and other nightshade plants (Solanaceae) several times in a row on the same area
- Optimum plant care to keep plants defensive
Nematodes on tomatoes
Nematodes (Nematoda) are also called roundworms and occur as parasites in soil, water and living organisms. Depending on the species, the nematodes attack the flowers, leaves or roots of the tomato, but they can also be used as beneficial insects in biological crop protection. They enrich themselves by liquefying and absorbing the contents of entire cells. In addition, nematodes can also transmit viruses. An infestation is difficult to spot. Signs of wilting despite adequate water supply, reduced growth or black discoloration at the base of the stem can be indications.
Control of nematodes on tomatoes
It is not possible to combat the harmful nematode species with a pesticide on tomatoes, as no agent is approved in Germany. So let's take a look at the other options:
For example, growing marigolds, especially the species Tagetes patula, can help with a nematode infestation on tomatoes. The marigold (Tagetes) produces a nematicide in its root cells - i.e. a poison against nematodes. Although marigolds only help against the nematode genus Pratylenchus, in generalHowever, it is wise and helpful to include marigolds in the crop rotation, as these are not hosts for nematodes. Planting marigolds among the tomatoes is also an option, but with much lesser effect.
To combat tomato-damaging nematodes, we recommend consistent crop rotation or the use of resistant varieties such as: 'Campari', 'Dolcevita', Tropical 'Matias' and 'Piccolino' and the rootstock 'Vigomax'.
Summary: Controlling Nematodes on Tomatoes
- Tagetes as a catch crop on an area previously cultivated with tomatoes
- Do not grow tomatoes or other nightshade plants (Solanaceae) for several years on the same area
- Choose resistant tomato varieties
Prevent tomato pests: How to protect your tomatoes
In general, the best preventive measure is to provide the plants with the best possible conditions. This includes, above all, a needs-based supply of nutrients. We recommend that you ensure a good supply of potassium and moderate nitrogen fertilization. Suitable fertilisers, such as our Plantura organic tomato fertiliser, help you to optimally care for the tomato plants. A planting distance of about 70 centimeters in the grown soil reduces competition for nutrients and slows the spread of diseases or pests.
Many pests thrive in greenhouses. Therefore, we recommend checking the plants regularly for pests, especially in protected cultivation, in order to prevent mass propagation. Some pests also like dry air, which is why you can work preventively with a slightly higher humidity level.
In the garden, encouraging beneficial insects is another very helpful way to prevent problems with pests. We recommend that you use plant protection that is gentle on beneficial insects, for example with compatible household remedies and organic plant protection products. You can also welcome beneficial insects with breeding facilities such as an insect hotel. A flower meadow that is as untouched as possible offers beneficial insects a home in your garden. Our beneficial insect magnet is a seed mixture that makes it easy for you to create such a flower meadow.
Sensible crop rotation for tomatoes helps you not to exhaust the soil from one side and stops the accumulation of diseases and pests from one growing year to the next. Therefore, we recommend that you on theArea on which you plant tomatoes in one year, at least in the two following years another crop, such as lettuce (Lactuca sativa) or spinach (Spinacia oleracea ) to plant. Plants related to the tomato, such as potatoes (Solanum tuberosum) or aubergines (Solanum melongena) should also not be planted there during this time, as they same diseases as tomatoes.
A heavy infestation by pests is less likely with a mixed culture of tomatoes than if you plant a monoculture. For example, parsley (Petroselinum crispum) and basil (Ocimum basilicum) keep lice away from tomatoes with their essential oils. Onions (Allium cepa), leeks (Allium ampeloprasum) and garlic (Allium sativum) are also excellent Neighbors for tomatoes, as these mainly drive away whiteflies (Aleyrodidae). Marigolds are a nice touch of color in the bed and help a little against root nematodes.
A mixed culture is not only useful with regard to pests. A socialization of different plants in a bed ensures a stronger shading of the soil surface. This not only protects the soil from drying out, but also suppresses weed growth. In addition, the nutrients available in the soil are used better than if only one species is planted in the bed.
Not only pests can endanger the tomato harvest. Tomato damage also occurs for environmental and physiological reasons. We'll show you how to recognize them and how to prevent them.