Aphids are very small insects that often attack vegetable garden crops, not for nothing they are also known as plant lice. They nest mainly on the leaves and suck their sap, affecting in particular the most tender parts of the plant.
In nature there are many species of aphids, each selectively attacks only some types of plants and is distinguished by a different color, from green to black or reddish. They are very annoying for the garden because they often transmit virosis to plants, the damage, in particular, some vegetables because by sucking the sap they crumple the leaves, they affect in particular the most tender parts of the plant. The negative effect of the presence of aphids is also honeydew: a sugar secretion that causes sooty mold, cryptogam disease.
Defending against aphids is also possible without using chemical pesticides, there are several plant preparations that can help us and that is harmless to humans and the environment. Let’s see below how to recognize the attacks of aphids and the methods to combat them while remaining in the organic cultivation method.
Recognizing aphids on plants
It is not difficult to identify the presence of aphids: groups of insects attached to the leaves of the plant are noted. They often gather on the bottom page of the leaves, as a result of which crops must be monitored periodically. If they are found immediately it will not be difficult to remove them, even manually, but woe betides letting them spread. When you see black patches on the plant it may be that the honeydew of the aphids has caused fungal disease, sooty mold.
Aphids have generations with or without wings, the winged generation is born with ideal conditions, they follow to multiply in various generations without wings up to a new flying generation. There are several species of aphids, for example, black aphids attack beans and beans, gray ones are found on cabbage, brown-green aphids affect composite plants.
Aphids and ants
Ants sometimes live in symbiosis with aphids, in practice the ants take care of transporting aphids on the plants, where they breed them, exploiting them to produce honeydew, a substance of which the ants are greedy. The problem is that the fact that ants carry aphids makes the spread of infestations of these pests much faster.
You have to be very careful if you notice a suspicious coming and going of ants in the garden and check if colonies of aphids appear. You can use mint macerate to dissuade ants from bringing insects to your crops.
Defense of the vegetable garden: how to get rid of aphids
A daily check can allow eliminating aphids effectively, especially if taken at the first migration it is possible to stop their spread easily. In organic farming, toxic acids are avoided, defending the garden with natural products. There are a number of effective remedies that can keep these lice away from our plants.
Manual deletion. In horticulture a valid method is still the manual elimination of plant lice, you can help yourself with jets of water or at the limit pruning the most affected parts.
We can also use micronized rock powders on the leaves, to discourage aphid bites (Cuban zeolite or kaolin are used in this regard).
Here we see in the video a 100% natural anti-aphid remedy, starting with garlic and Marseille soap. Let’s find the doses and how to make them at practically zero cost.
Insecticides against aphids
Pyrethrum. Pyrethrin kills aphids, acting by contact: it is necessary to hit the insect. Personally, I do not recommend the use of this insecticide that is not selective and is toxic, although allowed by the biological method, there are solutions against aphids with less impact. Wanting to use pyrethrum you have to do the treatments in the evening, you need to be careful to respect the period of deficiency of the insecticide if you spray on the parts of the vegetables that will then be collected or consumed. It is also important not to spray pyrethrum during flowering periods, so as not to risk inadvertently killing bees.
Neem oil. Neem oil (azadirachtin) is a natural and non-toxic insecticide, to be preferred against aphids over pyrethrum, precisely because of its lower toxicity.
Marseille soap. Diluted soap is a good anti-aphid repellent, in some cases, it also becomes acid, since it can cover the small body of the insect by asphyxiating it. It is also great for washing away the honeydew deposited on the leaves. In case of an attack of aphids, a nice passage with soap is always a good idea to do it.
White oil and soybean oil. Always to hit the aphids for asphyxiation we can use oily substances, in organic farming it is allowed the insecticidal use of mineral white oil, derived from petroleum, a more ecological alternative is soybean oil.
There are many natural substances that can ward off aphids, the great advantage of these methods is that the preparations with which to treat can be self-produced at a very low cost.
Most of these natural aphid remedies act as a repellent, without a knock-down effect on the insect.
- Garlic (macerated or decoction). Garlic squeezed and left a couple of days to infuse is an insect repellent. Even better than macerated works decoction of garlic. Contraindication is the pestilent smell of the preparation.
- Nettle macerate. It is prepared with a dose of 100 grams of dry leaves in a liter of water, after 2 or 3 days it is filtered and diluted 1 to 10. Formic acid has the function of fighting aphids.
- Fern macerate. Another substance useful to keep aphids away, in particular, it has a repellent effect.
- Rhubarb macerate. Thanks to oxalic acid, rhubarb leaves are a useful anti-aphid.
- Macerated chili pepper. Capsaicin is the substance that gives hot peppers, also useful to annoy plant lice.
- Propolis. It is believed that they have insecticidal effects in different preparations such as alcohol or hydroalcoholic solution.
- Other preparations: other macerated such as wormwood or tomato can also be useful to repel these plant lice.
The biological defense of ladybugs
In addition to the aphids, there are the natural predators of aphids, which can help in biological control: the main enemy of aphids are ladybugs, both as larvae and in the adult state they feed on plant lice. If you want to learn more you can read our article on how to attract ladybugs in the garden.
It is very useful to have ladybugs around the garden, care must be taken not to damage them with insecticidal treatments and to let them find good habitat, such as country hedges. Other insects that defend us from aphids are Chrysoperla carnea and earwig, let’s remember to treat them well.
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