Yew Pests

BLACK VINE WEEVIL

Black vine weevil is a chewing insect that affects Taxus (yew), Euonymus ‘Vegetus’ and Rhododendron.  The adult weevil is rarely seen.

SYMPTOMS

Crescent or bite-shaped notches on leaves.  Adults appear in late June and early July.  They feed at night, seeking refuge in mulch or leaf litter during the day.  The worst damage is caused by larvae consuming small roots and girdling bark from lower stems.

CONTROL

A systemic insecticide applied to the foliage will control adult beetles and prevent further egg laying.  Drench soil under shrubs to control larvae.  Apply 1x per month in May, June & July before damage appears.

 

FLETCHER SCALE

Fletcher scale is a sucking insect that affects yew.  Adults are shiny brown “shells” attached to the stems and under the leaves, usually on new growth.  Immature insects known as “crawlers” are rarely seen.

SYMPTOMS

Yellowing of the foliage and needle drop.  A sugary, sticky honeydew the scale secretes may support the growth of black sooty mold.  Densely trimmed or naturally compact plants may be more likely to be infested.

CONTROL

Use a systematic insecticide or contact insecticide when red buds are in bloom to kill overwintering females and nymphs. Apply a second application when grandiflora hydrangea are in bloom to kill newly hatched “crawlers” from eggs (that are not controlled by insecticides).

Note: Bonide Systemic Tree & Shrub Insecticide protects plants for a full year with one application in the spring.