Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Audio Play Icon Headphones Icon Plus Icon Minus Icon Check Icon Print Icon Note Icon Heart Icon Filled Heart Icon Single Arrow Icon Double Arrow Icon Hamburger Icon TV Icon Close Icon Sorted Hamburger/Search Icon
The Dirt

The Four-Lined Plant Bug

Photo/Illustration: Courtesy Jessica Walliser
Photo/Illustration: Courtesy Jessica Walliser

Pest profile

No gardener likes to spot damage on newly sprouted foliage. But inevitably, small, sunken pockmarks appear on the leaves of some 250 different plant species every spring. Although this damage looks like the handiwork of a disease, don’t be too quick to reach for a fungicide. Four-lined plant bugs (Poecilocapsus lineatus) could be to blame.

Endemic from Maine to Florida and from North Dakota to Texas-and everywhere in between-the four-lined plant bug’s distinctive damage is hard to miss. While foliar diseases tend to cause irregular edges and varied coloration, the initial circular scarring created by four-lined plant bugs has uniform edges and is often translucent. The affected leaf tissue eventually turns brown and may drop out, causing tiny pinholes in leaves. In some cases, the damaged leaf may also curl or crinkle.

This pest isn’t picky

Here are just a few of the plants the four-lined plant bug finds palatable:

Forsythia (Forsythia spp. and cvs., USDA Hardiness Zones 3–9)
Lavender (Lavandula spp. and cvs., Zones 5–9)
Salvia (Salvia spp. and cvs., Zones 5–11)
Shasta daisy (Leucanthemum × superbum cvs., Zones 5–8)
Viburnum (Viburnum spp. and cvs., Zones 3–9)


Snip off damaged foliage in summer

Four-lined plant bugs feed by inserting their mouthparts into leaves, injecting digestive enzymes, and slurping up the juices, leaving their telltale damage behind. Luckily for gardeners, these bugs produce only one generation per year, feeding for just a month before finding love, laying eggs, then biting the dust. Because their feeding period is so brief-and the damage is largely aesthetic-control measures are seldom warranted, although insecticidal soap and neem oil are fairly successful against them. Fall cleanups reduce the number of eggs hidden in plant stems, but they also eliminate overwintering sites for the beneficial predatory insects that help control pests. You’re better off just removing spoiled leaves in early summer, after the threat is gone.

Jessica Walliser is a horticulturist and the author of Good Bug Bad Bug. From Fine Gardening issue #146, page 22

View Comments

Comments

Log in or create an account to post a comment.

Related Articles

The Latest

Magazine Cover

Take your passion for plants to the next level

Subscribe today and save up to 44%

"As a recently identified gardening nut I have tried all the magazines and this one is head and shoulders above the pack."

Video

View All