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.
- 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.
- 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.
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: AnnuallyXytect 2F$69.60
Soil Application using Transtect
Dosage: 1 pkt/10 - 17 ft of shrub height Timing: Early spring Re-Treatment: AnnuallyTranstect$326.00
Foliar Spray using RTSA Horticultural Oil
Dosage: 0.25 - 2.0 gal/100 gal water Timing: Apply in Spring (GDD 179) Re-Treatment: AnnuallyRTSA Horticultural Oil$39.00
Foliar Spray using M-Pede
Dosage: 2% of 100 gal water Timing: Apply Spring (GDD 179 Re-Treatment: AnnuallyM-Pede$90.73
Soil Application using Xytect 75WSP 22 packets
Dosage: 1 pkt/24 - 48 ft of shrub height Timing: Spring or fallXytect 75WSP 22 packets$148.00
Foliar Spray using Xytect 75WSP 22 packets
Dosage: 1 pkt/300 gal water Timing: Spring GDD 179Xytect 75WSP 22 packets$148.00
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 forestryimages.org. Use of the images does not imply endorsement of treatments by forestryimages.org