Agriculture: Pear Pest Management Guidelines

Sampling At Bloom

During the bloom season examine flower clusters for pear psylla, mites, caterpillars, and thrips to determine your management needs. Also look for mealybugs and boxelder bug eggs and adults if they are a problem in your orchard.

Record your results (example formPDF).

How to Sample

From 50 trees collect one flower cluster from the treetop and one at eye level for a total of 100 clusters. Examine flower clusters with a 10 to 14X hand lens for these pests:

  • Pear psylla nymphs and eggs
  • Mites
    • European red mite eggs and adults
    • Pear rust mite.
  • Caterpillars on leaves and blossoms
    • Obliquebanded leafroller
    • Miscellaneous caterpillars (e.g., green fruitworm, fruittree leafroller)
  • Western flower thrips (Tap clusters on hand and look for dislodged thrips.)
  • Mealybugs (grape, obscure)
  • Western boxelder bug (eggs, nymphs, and adults)

Decision Table

Pest Management decision
Pear psylla
  • If 2 or more flower clusters have eggs and or nymphs, treat according to the Pear Pest Management Guidelines.
European red mite
  • If between 1 and 5 clusters have eggs, adding oil to the first codling moth spray may be adequate.
  • If more than 5 clusters have eggs, treat with oil at egg hatch according to the Pear Pest Management Guidelines.
  • If more than 10 clusters have eggs, add a miticide to the oil according to the Pear Pest Management Guidelines.
Pear rust mite
  • If present, treat according to the Pear Pest Management Guidelines.
Obliquebanded leafroller
  • If only one larva was found, use pheromone traps to monitor the first summer flight according to the Pear Pest Management Guidelines.
  • If more than one larva is found, treat immediately according to the Pear Pest Management Guidelines.
Western flower thrips
  • If several thrips can be seen on the cluster or dislodged onto a paper, treatment may be needed; see the Pear Pest Management Guidelines for details.
Mealybug nymphs (grape, obscure)
  • If 4 or more top flower clusters are infested, treat according to the Pear Pest Management Guidelines.
  • If less than 4 top flower clusters are infested, resample in a week.
Western boxelder bug
  • Spot treatments may be adequate in orchards near riparian areas; treat according to the Pear Pest Management Guidelines.

Important Links

Text Updated: 11/12
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