How and what to use to combat pear psyllid

Diseases and pests

Most fruit tree diseases resemble pest infestations. Not all of them are easy to spot with the naked eye—the pear leafhopper, or psyllid, is a very small insect. But even if small, these pests multiply rapidly and can destroy the tree. Before treating the plant, it's important to identify treatment methods and products. It's recommended to review descriptions and photos of similar infestations. This problem can be addressed in a variety of ways, including chemicals and less hazardous solutions.

Leafhopper – general information about the pest

The pear psyllid, or common pear psyllid, is a widespread pest classified as a monophage. It is found almost everywhere where pear trees grow, including central Russia, Ukraine, and Belarus. It is often found on trees in the Leningrad Region. It is rare in Karelia, but it does occur. The main signs of a psyllid presence on a tree are:

sticking and falling of leaves;
spoilage of the general appearance of fruits;
increased pulp density;
bland taste of fruits;
development of sooty mold.

Pear psyllid larvae secrete a sticky substance called copper mildew during feeding. This substance is the source of active fungal growth, which causes a black coating to appear on the fruit, foliage, and branches of the tree. If you approach an infested pear tree too closely without a hat, there's a high risk of your hair becoming matted with the copper mildew.

Note!

Monophages are creatures that feed on only one food item. In the case of the leafhopper, this could be apple or pear trees. Each individual case has its own specific diet. Among mammals, only koalas are considered monophagous—they eat exclusively eucalyptus leaves.

Description

There are two types of pear psyllid: yellow and spotted. The latter type is the most dangerous and damaging. Adults resemble small winged midges. Their coloration varies from orange to dark brown, depending on the season. Stripes or spots are often visible on the thorax. Their size rarely exceeds 2.5-3 mm, making small populations and the onset of infestation difficult to detect.

The imago is the fully developed form of the leafhopper. Upon reaching maturity, females lay grayish-white eggs on plant leaves and at the base of buds. These eggs turn orange as they mature. The larvae (nymphs), which hatch within 6-20 days, undergo up to five developmental stages before becoming fully developed insects. Male leafhoppers die immediately after mating.

Lifestyle

Overwintered pests begin actively mating as temperatures rise to 5ºC to 10ºC. The total number of eggs laid in a single clutch at the beginning of the season can reach 400. A single female can produce up to 4-5 such generations. If temperatures have already reached 20-22ºC, the clutch size can reach 1000-1200 eggs. The main locations where egg clutches can be found are:

bases of the kidneys;
leaf blades;
peduncles.

After hatching, leafhopper nymphs begin feeding on tree sap. Initially, their primary habitat is the tree buds. Later, they migrate to the leaves and then damage young pear shoots. Once the nymphs reach maturity, the entire process begins again. Insects that do not reach maturity before the onset of cold weather die.

Note!

The insect's spread to other plants is due to the psyllid's ability to fly - its wings are developed enough to move between distant areas.

Development cycle

The spotted psyllid hibernates on pear trees, while the red psyllid usually waits out the cold on other plants and appears near pear trees only in spring. The females of this pest begin to become active with the spring warming in April-March. The primary initial egg-laying site is the woody shoots of fruit trees. Later, egg masses can be found on buds and leaves. Each psyllid egg is no larger than 0.3 mm in size and has a stalk at its base, which anchors it to the surface. The stages of development and metamorphosis of psyllid nymphs are:

A newly hatched insect larva is no larger than 0.36-0.54 mm. Its body is orange with occasional brown spots on its back. The antennae on the insect's head are three-segmented, each with a single rhinarium.
By the second stage of psyllid nymph development, the body gradually becomes lighter. The insect's length does not exceed 0.55-0.72 mm. Other characteristics remain unchanged.
During the third stage of development, the psyllid larva changes color to grayish-yellow. Its body size increases to 0.75-1 mm. A second rhinarium forms on the outermost segment of the antennae.
The fourth stage of development is characterized by body sizes ranging from 1.1 mm to 1.35 mm. The insect's coloration also changes to a greenish-yellow. The antennae grow to five-segmented, with one rhinarium per 3 and two per 5.
When leafhopper nymphs reach stage 5, their body length can reach 1.56-1.9 mm. Their coloration becomes greenish-brown. The antennal structure is seven-segmented, with two rhinaria on the 7th segment and one rhinaria each on the 5th and 3rd segments.

Wing cases begin to develop only during the last two stages of nymphal remodeling. Over the summer, before wintering, up to 4-5 generations of leafhoppers can occur. If the initial spring population of leafhoppers on a pear tree is small, early chemical treatment is not recommended; it's best to wait until June. Otherwise, it's recommended to begin control before the first signs of bud development appear.

Attention!

In terms of the timing of the development of the first egg-laying, the appearance of the first nymphs of the pear leafhopper coincides with the activity of the buds and the formation of ovaries.

The harmfulness of the leafhopper

The main danger of this parasite on pear trees is not only related to the development of nymphs—the adult insect also feeds on sap. Psyllable larvae primarily parasitize leaf blades and young shoots. However, the greatest damage is caused by the distribution of eggs primarily around the buds. The first nymphs, after the spring warming, develop into full-fledged insects, just in time for the mass flowering of the trees. Due to damage to the surface layer of bark on the shoots, the presence of parasite waste, and reduced sap flow in the leaves, the following changes are observed:

buds and leaves fall off;
the formed ovaries are small and dried out;
the appearance of sticky plaque and sooty mold.

As a result, photosynthesis is disrupted and the plant's overall immunity is weakened. If pear trees are infested with psyllids, there is a risk of attack by other pests and the active development of various fungal and bacterial diseases. Trees infected with psyllids often wither. In a single season, a pear tree infested with psyllids loses at least half its crown. If the pests are not eradicated, the least damage that can occur is a lack of harvest for the following seasons.

The similarity of the pear psyllid with the apple psyllid

Apple and pear psyllids are closely related. These pests move around the garden and between branches using their wings and stilts. The main difference between these parasitic insects is their primary food source. The apple psyllid is distinguished by its orange-yellow color. Distinguishing characteristics of the common apple psyllid also include:

Egg laying occurs in the autumn season, and nymphs appear only with the onset of warm weather.
During one warm period, the apple psyllid can produce only one single offspring.
Adults (imago) do not feed on tree sap – the apple tree is needed only for the development of larvae.

Note!

Given the apple leafhopper's lower activity and reproduction rate, controlling this pest isn't as difficult as controlling the pear leafhopper. However, it's important to remember that the appropriate treatment is tailored to each individual case.

Methods for protecting pears and eliminating pests

The key to protecting pears from psyllids is proper care. If a mature plant has fewer nesting sites, the number of insects will decrease significantly. For this reason, experienced gardeners recommend stripping off the surface, almost fallen bark, and removing moss from the trunk. Dwarf pear varieties also typically experience peeling of the surface bark layer. Various methods can be used to eradicate the insects, but preventative treatments are paramount, as it's best to prevent pest reactivation and enjoy a full harvest during the warmer months.

Compositions of chemical origin

The use of strong chemicals against pear leafhoppers should be justified. Such compounds pose a danger not only to the pest but also to humans, as residual particles can even remain on the fruit. However, with a large infestation of these small pests, mild control methods are practically impossible. The choice of treatment for pear trees depends on the timing of treatment:

During the period of budding, before the flowering stage - "30 Plus", "Prophylactin", "Aktara", "Shepra", "Fastak 100 EC.
After the buds appear on the branches of the pear, the following varieties are common: “Akaramik”, “Movento”, “Dimilin”.
In autumn, to destroy adults before the onset of cold weather, Fufanon and Kemifos are better suited.

Early treatment of trees with chemicals makes subsequent pest control easier. Depending on the composition, the targeting can vary – targeting egg-laying insects, nymphs, or adults. Killing adult insects is more effective in the fall, as larvae and eggs cannot withstand the cold, and reducing the number of leafhoppers before wintering will improve the situation in the spring.

Attention!

The advisability of using hazardous chemicals against pear psyllid can be determined by the concentration of egg masses on leaf blades. Such measures to eradicate the pest are mandatory if the number of egg masses detected is at least 10 per 100-120 leaves.

Biological method or natural enemies of leafhoppers

The use of various chemical compounds may be justified. However, to prevent such a large number of eggs from forming on the plant and from the pear psyllid, you can use the method of introducing natural enemies. With this type of presence, the number of psyllids will be naturally reduced, without chemically harming the tree or other vegetation in the area. Insects that can be attracted include:

ground beetles;
lacewings;
aphid beetles;
spiders;
ladybugs.

To attract these beneficial neighbors to a pear tree, it's recommended to simply plant annual legumes near the roots. Clover and alfalfa can be added to this group. Many insects develop in the branches of these plants, and when mown, they begin to seek out the nearest food source, which is the nymphs and adults of the pear leafhopper.

Folk remedies for the destruction of leafhoppers

When pears are in the early stages of being infested by leafhoppers and their nymphs are still relatively rare, the fruit tree can be treated with homemade folk remedies. These treatments cause significant damage to the insects without damaging the plant or spoiling the harvest. The most common folk remedies for controlling pear psyllids are:

Prevention

Controlling a pest like the pear psyllid is time-consuming and requires investment. Preventative treatments are cheaper and easier to perform beforehand to increase the tree's resistance to most pests and diseases. To ensure the tree remains healthy and free from pest risk, the following methods are recommended:

timely pruning and general shaping of the tree crown;
removal of plant debris from all fruit trees on the site;
cleaning the tree trunk from loose bark and moss growths;
burning or treating leaf litter with disinfectants;
annual digging of the root area of the tree;
whitewashing pear tree trunks and forming protective oil circles;
Spring preventive treatment with copper sulfate and urea.