Insect Pests of Pear Trees
There are multiple insect pests that can cause harm to your pear tree, but there are two which home-growers should be particularly wary of. They are the pear psylla and the coddling moth.
Pear psylla (Cacopsylla pyricola)
Pear psylla adults look like tiny cicadas! (Utah State Extension)
The insect pest know as pear psylla is among the most common of the insect pests of pear trees. They are very small hemipterans (“true bugs”) that resemble tiny cicadas. Due to their size, it is often easier to identify this pest based on the damage found on your tree rather than the insect itself.
Pear psylla nymphs produce sticky honeydew. (W. Cranshaw)
Leaves tend to blacken and/or yellow and fall off. Heavy infestations can lead to dramatically impaired and stunted growth and fruit production. Unfortunately, if your tree is exhibiting these symptoms and you think Pear Psylla might be the cause, extensive and sometime irreversible damage may have already occurred. The best way to manage this pest is to be diligent in your preventative measures, rather than waiting for an infestation to occur and treat it afterwards.
The best way to prevent a Pear Psylla infestation is to remove small growths that sprout from the root stock of the tree, known as “suckers.” These suckers can have other harmful effects on your tree, such as stealing nutrients from the grafted area of the tree, so removal of the is generally a good idea. You may have to remove some soil to find the base of the sucker, and they may have to be removed multiple times, as they have a tendency to grow back.
Codling moth (Cydia pomonella)
Codling moth adults are rarely seen unless a pheromone trap is used.
Like the pear psylla, the codling moth is an insect pest of which growers should be wary. There are two life-stages during which this pest can be identified: larval and adult. The adult codling moth is approximately ½ – ¾ inches long and sport mottled grey wings which are held like a “tent” over their bodies. The larvae, however, look much different. Their bodies are white or pinkish in color with dark brown heads. Size varies depending on the age of the larva.
Codling moth larvae burrow into the fruit to feed on the seeds.
The damage caused by this pest is found on the fruit itself. A good indicator that your tree has codling moths is the presence of small holes on the surface of the fruit that are filled with red-brown crumbly droppings. Take action if these symptoms overtake the tree.
Fruit Bagging: To control codling moth, #2 bags may can be placed over the individual fruits 4-6 weeks after the tree blooms when the fruit is ½ – 1 inch in size. Although this tactic may be viewed as labor-intensive, results are relatively effective.
Trunk Banding: This tactic should be employed in the late fall when the caterpillars are getting ready to pupate. Place a rough band around the trunk. This could be corrugated cardboard or burlap. After a day or two, remove the band and destroy it (and the cocoons attached). This process should be repeated until no more cocoons are found in the band.
Pear Psylla – University of California IPM
Codling Moth: Control in Home Plantings – Colorado State University Extension
Growing Apples in the Home Orchard (information is useful for pears too!) – OSU Extension Ohioline
The Midwestern Home Fruit Guide is a regional bulletin that covers all the fruits that a home gardener may wish to grow. It is a “for sale” bulletin, but well worth the $24!! Click on the title to go to a web page for ordering this guide. This bulletin covers cultural and chemical control of diseases and insects that attack fruits.
(We wish to thank Dr. Celeste Welty for consultations!)