Boxwood Leaf Psyillid Diagnostic Guide

Shrubs at Risk

Boxwoods are susceptible to leaf psyllids.


Signs of Damage

  • Leaf cupping from nymphal feeding is a distinguishing symptom.
  • As new foliage is rapidly growing, nymphs use their piercing sucking mouthparts to feed on young leaves and buds.
  • Later in the season the plant may outgrow the damage since there is only one generation per year.
Boxwood Leaf Psyllid Signs

Brian Kunkel, University of Delaware,

Physical Appearance

  • Adults look similar to tiny cicadas and jump as plant lice in May and June.
  • Nymphs are covered with white, waxy filaments and can be found near developing leaves prior to May.
  • Eggs are orange, small, and are deposited in leaf buds in late summer and early fall.
Boxwood Leaf Psyllid Signs

Whitney Cranshaw, Colorado State University,


  • Nymphs begin feeding on tender new leaves and buds. Nymphs go through several instars before molting into adults in early June.
  • Adults emerge in late May or June as jumping plant lice.
  • Insect overwinters as eggs laid in the buds.
  • One generation per year.

Treatment Strategy

Damage from the boxwood psyllid is mostly aesthetic. Depending on the situation, control may not be necessary. If the population is identified early enough, pruning out affected areas is a possibility. Another option is to use systemic insecticides like Xytect™ or Transtect™, which work from the inside of the plant, controlling actively feeding psyllids.

  • Soil Application using Xytect 2F

    Dosage: 0.1 - 0.2 oz/ft of shrub height
    Timing: Fall
    Re-Treatment: Annually
    Xytect 2F Insecticide
    Xytect 2F Login for pricing
  • Soil Application using Transtect

    Dosage: 1 pkt/10 - 17 ft of shrub height
    Timing: Early spring
    Re-Treatment: Annually
    Transtect 70WSP Insecticide
    Transtect Login for pricing
  • Foliar Spray using RTSA Horticultural Oil

    Dosage: 0.25 - 2.0 gal/100 gal water
    Timing: Apply in Spring (GDD 179)
    Re-Treatment: Annually
    RTSA Horticultural Oil
    RTSA Horticultural Oil Login for pricing
  • Foliar Spray using M-Pede

    Dosage: 2% of 100 gal water
    Timing: Apply Spring (GDD 179
    Re-Treatment: Annually
    M-Pede Insecticide/Fungicide
    M-Pede Login for pricing
  • Soil Application using Xytect 75WSP 22 packets

    Dosage: 1 pkt/24 - 48 ft of shrub height
    Timing: Spring or fall
    Xytect 75WSP 22 packets
    Xytect 75WSP 22 packets Login for pricing
  • Foliar Spray using Xytect 75WSP 22 packets

    Dosage: 1 pkt/300 gal water
    Timing: Spring GDD 179
    Xytect 75WSP 22 packets
    Xytect 75WSP 22 packets Login for pricing

Treatment Expectations

This is not a pest that will kill or seriously disfigure plants. At most, it causes some curious looking foliage in the spring which grows out by summer. If control is necessary, timing must be made top priority. Though the adults feed later in the year, the nymphs do most of the damage and should be targeted. Boxwood leafminer will also be controlled by a Xytect™ or Transtect™ treatment.

A Diagnostic Guide is designed to help you identify a pest issue and management solutions. Always refer to product label for all rates and approved uses. Some images courtesy Use of the images does not imply endorsement of treatments by

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