Holey Viburnum Leaves!

Control: 

• Avoid susceptible varieties: European cranberrybush viburnum (V. opulus), arrowwood viburnum (V. dentatum), American cranberrybush viburnum (V. opulus var. americanum) and David viburnum (V. davidii).
• Resistant viburnums include Korean spice viburnum (V. carlesii) Judd viburnum (V. x juddii), doublefile viburnum (V. plicatum f. tomentosum).
• When purchasing viburnums, inspect plants thoroughly for any signs of VLB, including viburnums grouped together in the nursery.  
• When plants show symptoms of an infestation, look for their eggs in autumn, from October to spring. Inspect stems closely for little pits packed with eggs. Destroy any infected twigs; do not compost them.
• Encourage natural predators, green lacewings, assassin bugs, lady bugs, and spined soldier bugs, during the growing season - by not using pesticides!​
• Apply dormant oil/lime sulfur in late winter before bud break to kill them as they overwinter on the twigs. For more on applying dormant oil and lime sulfur click here. 

Tattered viburnum leaves that resemble lace more than foliage, are symptoms of viburnum leaf beetles (Pyrrhalta viburni). Both the adult beetle and their larvae feed on many types of viburnums. The adult yellowish-brown beetles are ¼ long. The 1/3 inch long larva has noticeable black spots on their beige to yellow-green bodies.
 
The larvae emerges in May and feeds for several weeks. In mid-June the larvae return to the soil to pupate. In late June to early July, hungry adult beetles emerge and they chew oblong holes in the foliage. Plants can become completely threadbare and may die with repeated infestations. During the summer and through to October, females deposit their eggs into pits they’ve made in the stems. The eggs overwinter and emerge in spring as larvae.