Flying Red Insects on Boxwood Bushes

Identification

• One of the most serious pests of boxwoods is the boxwood leafminer, which is present all over the United States. Leafminers are tiny maggots that feed in between the upper and lower sides of boxwood leaves, according to the Missouri Botanical Garden website. While young, boxwood leafminers are reddish-orange and swarm around boxwoods.

Symptoms

• Symptoms of boxwood leafminer infestation include blister on lower leaves, off-colored leaves and premature leaf drop. Leaves attacked by this insect turn yellow and are small in size. Boxwoods infested with leafminers usually appear unhealthy.

Control

• Selecting pest resistant cultivars is one way to prevent infestation of boxwood leafminers. According to the Missouri Botanical Garden, resistant cultivars include Pendula, Varder Valley and Suffruticosa. Spiders are natural predators that aid in the control of insects such as the boxwood leafminer. Applying pesticides to shrubs in the first part of May, with a second in midsummer is often effective in control of this pest.