How to combat and control pear psylla

One of the most common and easy to identify pests is the pear psylla. If you have the pleasure of having a pear tree in your orchard, the symptoms of this insect will be very familiar to you.

In this article, more than in the description of the pest, we are going to offer you the different solutions currently existing against this pest, the pear psylla, which can give you many problems during fruiting.

In Spain, we can classify 3 important problems in pear cultivation. One is fire blight , caused by bacteria ( Erwinia amylovora ), a physiopathy known as brown heart , and, of course, pear psylla .


Its scientific name is  Cacopsilla pyry  L. The adult is a species of small fly. The larvae, carried out by the spawning of the adults, cause multiple direct and indirect damages. Symptoms of pear tree disease caused by pear psylla are easily identifiable.

The pear psylla becomes active in spring, just coinciding with the emergence of buds, new stems, leaves and the subsequent fruit set.

From 10 ºC, where in many areas of Spain, it begins before spring, the adults become active and mating begins.

The rising temperature in spring plays a fundamental role for the full development of the pest in the crop. With 10 ºC of temperature , the complete cycle of this insect takes up to 100 days. From 20ºC, whose temperatures can be reached in early spring, the cycle is reduced to 30 days.

Direct damage:  the first feeding of the pear psylla is done on young stems and leaves. They cause direct damage by reducing the growth of these vegetative parts, malformations and direct excretion of a sticky molasses.

Indirect damage:  the molasses produced in direct damage falls through the stems and even the trunk, stains leaves, reduces their photosynthetic capacity and attracts fungi (bold).

Virus transmission by direct bite has also been quantified.


The first detections can be made even from afar. When we look at the vegetative parts of a pear tree (stems and leaves), we see that they glisten or shine when the sun hits them.

This is due to the honeydew that the insects produce when they bite the leaves and stems of the crop.

As we zoom in, we see a sticky liquid that turns black over time and even drips onto the log.

Leaf pear psylla damage, with molasses production


Currently we can consult in the phytosanitary guide of the Ministry of Agriculture, the products authorized for the control of psila del peral.

It is important to check the safety period for the future harvest of the pears, as well as to respect the number of treatments, mixtures, etc.

In this link ” Register of phytosanitary products “, you can consult the products authorized in Spain to reduce the plague.

Among the most used and recommended products are the following:

  • Abamectina 1,8%
  • Acetamiprid 20%
  • Acrinatrin 7,5%
  • Deltametrin 2,5%
  • Lambda Cihalotrin 1.5%
  • Tiacloprid 48%
  • Thiamethoxane 25%

Along with these treatments, wetting agents, surfactants, and cleaners or chitin breakers, such as soaps, are often added. Thus, it is also possible to eliminate the molasses that is produced during the bite and future problems derived from the appearance of diseases.

A typical treatment for a pear farm, where the pear psylla is controlled would be the following:

  • January treatment:  paraffin oil and repeat treatment after 15 days.
  • Treatment in spring (petal fall):  insecticide within the previous authorized list.
  • During the development of the fruit: 2 or 3 treatments of potassium soap or other soaps.


Faced with these types of problems, prevention and prior control of pear psylla is essential to avoid treating when the damage is already present.

We can find different pest management guides , trying to cancel its expression or identify the exact moment of the application of the control products against the pear psylla.

The difficult management of the pest, which causes many pear tree products, is due to the molasses produced, which is very difficult to eliminate, even with the use of soaps.


The processes of identification and control of the pear psylla begin in winter. Counts and estimates of the presence of the pest can be made.

From winter, evolving until spring, we can observe the growing organs and identify possible clutches.


The balanced maintenance of the crop, since it leaves the winter phase is very important. We must control the nitrogen inputs, avoiding an excessive contribution that leads to a great development of leaves and stems.

Remember that the important thing is in the flowering capacity of the plant and its subsequent fruit setting. Not the fact of having an oversized production of sheets entails having a higher future production.

In fact, an excessively vegetative phase, where nitrogen predominates over other nutrients, entails a delay in flowering, a decrease in its potential and a poor transformation of sugars.


As the pear psylla is a big problem for the pear tree , different “guardians for your crops” have been studied and tested, especially in the case of organic pear trees where the use of products is much more limited.

The main biological enemies are hemiptera of the Anthocoridae and Miridae families  . The most widely used and famous for control is  Anthocoris nemoralis.


Once we have reduced or eliminated the pest, we are faced with another danger from the subsequent introduction of diseases. They take advantage of the sugar content in the leaf and the general weakening caused by the psylla of the pear tree.

What we will have to do is remove or clean the leaves and stems of said molasses. For this we have different solutions, such as potassium soap . 

Keep in mind that it is very likely that you will have to do a minimum of 2 treatments to remove the sticky molasses that remains on the leaves.

Welcome to The GardenPure! My name is Ryan Heagle, and I’m the founder of The GardenPure, I spent the first part of my adult life teaching and then living in Australia in various business ventures, the first of which was a business devoted to the sale of house plants.  I am now a full time blogger. I am a self taught gardener.

Ryan Heagle

Welcome to The GardenPure! My name is Ryan Heagle, and I’m the founder of The GardenPure, I spent the first part of my adult life teaching and then living in Australia in various business ventures, the first of which was a business devoted to the sale of house plants.  I am now a full time blogger. I am a self taught gardener.

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