Black & White Striped Beetle

 

Questions From Our Help Desk

Volunteers from Fairfax County Master Gardeners and Green Spring Master Gardeners staff the horticulture help desk to answer gardening questions and help solve gardening problems.

Here we present the most commonly asked questions recently submitted to the Help Desk, and the associated responses. You can submit your gardening questions and problems to the Help Desk to receive researched-based answers. Instructions and contact information are found on the Help Desk page

Black and White Striped Beetle

striped bugA black and white beetle-like insect with a red head looks to be damaging my lavender, oregano, and obedient plant. The damage looked like a group of small brown dots on the leaves, and I am guessing it had started about one to two weeks ago.
– Elizabeth / May 2025

The four-lined plant bug (Poecilocapsus lineatus) has yellowish-green bodies with 4 black stripes and an orange head. They are native to North America and produce one generation a year, with the adults being most active during May. The bugs feed by piercing leaves with their needle-like mouthparts, removing chlorophyll while they feed, and injecting an enzyme that results in brown spots on the leaves. They are particularly attracted to herbs, like our client’s lavender and oregano, which helped confirm the identification.

Damage is brief and plants can typically recover by mid-summer. Pruning out the damage in June after the adults are done feeding, is an option to rejuvenate the plants. The adult bugs have wings and move quickly, so control with a contact insecticide is difficult. They lay eggs in vertical slits along the stems of plants, and the eggs overwinter inside the slits. The best control is to cut back plants at the end of the season and remove the plant material to prevent a new spring generation.