How does the yellow spider mite affect plants and how is it fought?

The yellow spider mite is a major pest of the vine

Image –

Many pests can affect plants, so anyone who grows them should keep in mind that at least once a year an unwanted insect will be found on the leaves, flowers and/or fruit. Give priority to species typical of orchards and gardens, one of the most harmful is the yellow spidera mite that feeds on leaf cells.

It’s very small, so It is not always easy to see with the naked eye. In addition, it is interesting to always have a magnifying glass at hand, since it is a very useful tool to see if the plants have pests.


What is the yellow spider?

Two mites bear this name: the Tetranychus urticae and the Eotetranychus carpini. We are going to talk about both, because although they are very similar, the second is a much more recent plague that also has a preference for the vine. and charms.

Tetranychus urticae

The spider mite is yellow when young.

Image – Wikimedia/Gilles San Martin

It is a plague that receives several names: two-spotted mite (in reference to the black spots it has on each of its sides before completing its development), small yellow spider and, the most used: red spider, because when ‘it matures it is of this color.

Its life cycle is as follows:

  • Eggs: the female deposits them on the underside of the leaves. They’re tiny, rounded, and translucent, so it’s almost impossible to see them without a magnifying glass.
  • Larval and juvenile phase: they have a yellow body, with a dark spot on the flanks, and a whitish head.
  • Adults: turns red and measures about 0.5 mm.

These mites benefit from heat and low ambient humidity, so it is during the summer that they are most active.

Another important fact you need to know is that they have the ability to weave webs. These are very useful for them to move from one leaf to another, or even from one plant to another if it is close. Therefore, when you have one with this plague, you must also treat those around you because it is possible that it will also be affected, or that it will soon be if nothing is done.

What symptoms or damage does it cause?

those mites they feed on the cells of the leaves, and in doing so they leave pale spots that contrast with the green of the same. As a result, the plant has difficulty performing photosynthesis normally by losing chlorophyll, which is an essential pigment for carrying out this process.

If the blight spreads, it invades the entire leaf surface, further weakening the plant. As a result, other pests may appear, such as aphids, whiteflies and/or scale insects.

What plants does it attack?

to almost everyone. In fact, the difficulty is to know which ones it does NOT attack, since only a few (those with toxic sap, such as oleanders for example) are saved. For all these reasons, it does not hurt to inspect the plant well before even buying it, because in this way we avoid taking risks.

Eotetranychus carpini

Picture –

Picture –

This mite is called the yellow spider or yellow vine spider. Unlike the previous one, it has a much smaller body, with several black dots on its sidesinstead of one on each side. It also has eight legs.

Its life cycle is as follows:

  • Eggs: the females deposit them on the underside of the leaves. They are sphere-shaped and translucent.
  • Larval and juvenile phase: the yellow spider starts its life with a very light yellowish body.
  • Adults: they measure less than 0.5 mm, and are yellow in color.

It is a pest that goes unnoticed in autumn and winter, because the cold slows them down. Besides, the fertilized females spend these months hidden among the holes in the barkand when the weather improves, the first leaves affected are the basal leaves, that is to say the lowest.

What symptoms or damage does it cause?

Plants damaged by the yellow spider mite show the same symptoms as those attacked by the Tetranychus urticaethat is to say, will present these problems:

  • Appearance of discolored spots on the leaves
  • These leaves will lose chlorophyll, so they will eventually dry out.
  • Your growth will slow
  • In severe cases, other parasites will appear

But there is an important difference compared to the red spider: the first leaves affected will be the lowest.

What plants does it attack?

It mainly attacks vines, hornbeams and fruit trees like peach. Still, that doesn’t mean it can’t affect other plants. As I say, always, always, we have to review the plants, both the ones we already have and the ones we want to buy.

How to fight them? Let’s talk about chemical and ecological control

Treating Plants with Yellow Spider Mite

The first thing to keep in mind is that the yellow spider mite, whether of one species or another, is a mite. Mites are insects that multiply very quickly during the hot months, but less the rest of the year. Therefore, the best we can do is to prevent its occurrence, but how?

Well, it’s very simple:

  • If the ambient humidity is low, mist the plants with rain, bottled or lime-free water once a day. But I insist: it is only weak. To find out, you need to search the Internet for “humidity of X”, replace the X with the name of the city where you live, or buy a home weather station. And it is that if you spray water on a plant when it is already in a very humid place, it will rot.
  • Keep the plant well watered and fertilized. This will help reduce the risk of plague, and if it does appear, you will have more strength to survive it.
  • Avoid buying delicate plants. It is difficult, because delicate plants are precious. But it is advisable to acquire resistant species, which can live without problems in our climate.
  • Carry out preventive treatments with natural products, because it is already ready for use, once a month. This minimizes the risk of pests.

Corn, What do you do when you already have the yellow spider swarming freely on the leaves? The first step is to clean them with water and neutral soap. This will NOT eliminate the pest, but it will give the plants a break and, incidentally, it will help the acaricide we apply to it to be better absorbed.

And it is that if we want to completely eliminate this scourge, we have to apply an acaricide; non-insecticidal. Or, a double or triple action which is also acaricidal, like this one for example, which is a ready-to-use spray. You need to apply it all over the plant and both sides of the leaves. Follow the instructions carefully so that the efficiency is really good.

Yellow spider mite can be quite a serious problem, but we hope this article will help you, at least, to get it under control.

Leave a Comment