Knowledgebase

Identification of Insect Infestation on Boxwoods #788874

Asked May 02, 2022, 11:27 AM EDT

Hello University of Maryland Extension Service Expert, Please identify the insect infestation occurring on the pictured boxwoods. Are these insects harmful or beneficial to the shrubs? If the former, will an insecticidal soap- or neem oil--based spray be effective in eradicating them? Thank you for your assistance with this. Best regards, Germaine Timmermans

Prince George's County Maryland

Expert Response

Hi Germaine!

Boxwood Psyllids are the cause of the white sticky secretion on the leaves.  This pest causes aesthetic damage to American and English boxwood. Prune out and dispose of infested branch tips. Sprays are only necessary if infestations are heavy.

Boxwood psyllid nymphs may be controlled with horticultural oil or insecticidal soap sprays in April and May. Adults may be controlled by a registered residual insecticide in late May into June.

Jamie


Answered by the Home and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied May 02, 2022, 3:12 PM EDT

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