Viburnum leaf beetle

What is viburnum leaf beetle?

Viburnum leaf beetle is a leaf beetle native to Europe. It showed up in Ontario in 1947 and in New York in 1996 and has spread across much of the Northeast. Both the larvae and the adults eat viburnum leaves.

Larvae hatch in spring and feed in groups, first on the undersides and then right through the leaf, leaving a skeleton of veins. Adults come out in early summer and keep chewing holes until the first hard frost. Severe infestations can completely strip a shrub, and UW-Madison says that weakens the plant over time and can eventually kill it.

The weak point is the egg stage. Females chew small pits in young twigs, lay about eight eggs in each and cap them with chewed bark and droppings. Those twigs can be cut out and destroyed from October to mid-April, before the eggs hatch.

Signs and damage

• Leaves skeletonized between the veins in May and June by small larvae
• Round to oval holes chewed in leaves by adults from early summer until frost
• Rows of small bumpy caps on the underside of young twigs (egg sites)
• Whole shrubs stripped of leaves in bad years

Viburnum leaf beetle identification: what to look for

• Adult: Brown to yellowish-brown beetle about 1/4 inch long.
• Larva: Newly hatched larvae are about 1 mm, greenish-yellow or off-white. Grown larvae reach about 1/3 to 1/2 inch, yellowish-green to light brown with black spots and dashes.
• Eggs: Laid in rows of small pits chewed in young twigs, about 5 to 8 eggs per pit, each capped with chewed wood and droppings. Up to 500 eggs per female.
• Damage: Larvae skeletonize leaves between veins; adults chew round or oval holes. Heavy infestations strip the shrub.
• Timing: Larvae early to mid-May into June; pupate in the soil; adults from late June or July until hard frost; eggs laid summer into October.

Life cycle

One generation a year. Eggs spend the winter capped inside young twigs and hatch in early to mid-May. Larvae feed for several weeks through three stages, then crawl down and pupate in the soil under the shrub. Adults come out in late June to July, feed until a hard frost, and lay eggs in twigs from summer into October. Egg to adult takes about eight weeks.

When to look: Prune egg twigs from October through mid-April (Cornell). Check new leaves for tiny larvae in late April and May. Watch for adults from late June to frost.

Viburnum leaf beetle look-alikes

A few things get mixed up with it:

• Japanese beetle (Popillia japonica): Also skeletonizes leaves, but UW-Madison notes viburnum leaf beetle larval damage shows up earlier, in spring, and only on viburnum.

How to control viburnum leaf beetle

Cultural control

• Cut out and destroy twigs with egg caps from early October to mid-April, while shrubs are leafless. Cornell calls this probably the single most effective measure.
• For new plantings choose resistant viburnums. UMass lists David, Dawn, doublefile, Judd, Koreanspice, leatherleaf, Siebold and tea viburnums as most resistant.
• A sticky barrier wrapped around a band at the base of the shrub may catch larvae heading down to pupate; never put sticky material directly on bark (UMass).

Biological control

• Lady beetles, lacewing larvae, spined soldier bugs and assassin bugs eat the beetle; UW-Madison advises conserving these predators.
• UMass reports beneficial nematodes cut adult emergence in lab tests when applied before pupation; research is ongoing.

Chemical control

Dormant horticultural oil on egg-laden twigs before leaves come out (around mid-April) can cut egg hatch; Cornell cites preliminary trials showing 75 to 80% fewer hatching. Treat larvae when they first appear, usually late April or early May, covering the undersides of young leaves; Cornell names spinosad and insecticidal soap as lower-impact options that must contact the larvae, and warns that broad-spectrum sprays such as pyrethrins also kill the beetle's predators. Spraying adults or eggs works much less well. UW-Madison says soil drenches of clothianidin or imidacloprid can work if applied after flowering but before damage. Use only products labeled for this use; the label is the law. Pesticide work for hire needs a licensed applicator; see our pesticide applicator license guide. Muthler Landscaping does not spray or apply pesticides.

Use only products labeled for this pest and this site; the label is the law. For trees, work with an ISA Certified Arborist. If you hire someone to apply pesticides, make sure they hold your state’s pesticide applicator license; the rules for each state are in our pesticide applicator license guide.

Prevention

• Plant resistant viburnum species in new beds and screens.
• Inspect viburnum twigs for egg caps every winter.

When to call a pro

Call a licensed pesticide applicator if a large viburnum hedge or screen is being stripped every year and pruning can't keep up.

Related guides: Tree database: mature size and planting distance · Pennsylvania tree identification · Firewood rules by state · All pests and diseases

Questions about viburnum leaf beetle

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