Four-Lined Plant Bug Control: How to Get Rid of Four-Lined Plant Bugs

This page is a general four-lined plant bug control guide. Using the products and methods suggested will help you to completely control four-lined plant bugs in your property. Follow this DIY guide and use the recommended products and we guarantee 100% control of four-lined plant bugs.

Four-lined plant bugs are fast-moving insects known for their tenacious appetites across 250 species of herbaceous plants in gardens and landscapes. When you first look at brown spots on your plants it may come off as a bacterial leaf spot disease or fungal issue, but it could be the damage of the four-lined plant bug.

In most scenarios, their feeding activity causes moderate aesthetic damages to plants, but in larger populations or with on-going feeding activities leads to possible death of foliage. These little plant bugs can quickly dodge out of sight or fly away when disturbed making them a difficult pest to spot.

What they cannot hide is their voracious appetites', and with their chewing-sucking mouthparts they can leave behind numerous holes in the plant leaves. A few amount of these pests are enough to quickly distort the appearance of desired foliage, but with the quick use of the products and steps in this DIY guide it can be prevented.

Identification

Before proceeding with treatment, you will need to be sure that pest infesting your property is a four-lined plant bug. Misidentification can lead you to using the wrong products and treatment approach, which can cost you time and money. To know what four-lined plant bugs look like, refer to the following characteristics:

• Four-lined plant bugs are small, agile pests measuring about 7.5 mm long, and 3.5 mm wide.
• They have a orange head, dark reddish-brown eyes, yellow to green color with four black stripes running lengthwise along the wings. In their first nymph stage, four-lined plant bugs are dark red with a row of block dots on the thorax and more oblong shaped bodies that elongate and change color as they mature. In later stages, they gain a yellow stripe. In the final nymph stage, they turn from bright red to bright orange with black lateral stripes on the thorax. In total, they reach adulthood in as little as 17 to 20 days.
• Both the nymphs and four-lined plant bug have piercing-sucking mouthparts to insert into leaves to ingest chlorophyll.
• Four-lined plant bug eggs are 1.65 mm long with a cylindrical, yet slightly curved shape and have a striated cap on the upper third making it appear the same shape as a banana. The eggs start off as light yellow in color later becoming reddish with age.

Use the images and description above to help you properly identify a four-lined plant bug. If unsure, then contact us with a photo of your pest by email or visit one of our store location with the photo or a sample of the pest in a sealable plastic container. By doing this we can help in proper identification and suggest the appropriate treatment plan for the pest infesting your property.

Inspection

After properly identifying the four-lined plant bug, you can proceed with an inspection on your property. During this phase you are looking for areas the pest is frequently visiting, and the conditions allowing it to thrive.

Where to Inspect

The four-lined plant bug feeds on over 250 plant species, many of which are herbaceous plants, trees, and shrubs. They are most commonly seen on herbaceous perennials (chrysanthemum, Chinese lantern, liatris, and shasta daisy), herbs (mint, and basil), woody ornamentals (azalea, dogwood, forsythia, viburnum, amur maple, and sumac), flowering annuals (zinnia, and marigold), berries (currant, and gooseberry), and vegetables (peppers).

Adult four-lined plant bugs feed on the upper surface of host plant leaves, then they may quickly fly away or hide from your view. Female four-lined plant bugs lay one generation of pests per year in 2 to 3 inch vertical slits along the host plant stems. These eggs will overwinter then hatch in the spring.

What to Look For

From May to early July, feeding damages from both the nymph and adult four-lined plant bugs appear as white or dark spots with a stippled appearance, which eventually becomes black or translucent and turn into holes on the host plant leaves resembling some foliar plant diseases.

In major infestations, prolonged feeding activity may cause plants to yellow, wilt, or curl. 

Treatment

Once you are ready to get rid of the four-lined plant bugs, you will need to wear the proper personal protective equipment (PPE) to protect yourself against pest and pesticide material.

Four-lined plant bugs overwinter as eggs when inserted into plant stems so for this reason you will want to use a long-lasting residual insecticide. Residual insecticides formulated with the active ingredient bifenthrin, cyfluthrin, lambda-cyhalothrin, or permethrin are most effective against four-lined plant bugs.

Step 1: Prune Damaged Leaves

The best thing to do first when controlling four-lined plant bugs is to remove damaged leaves, stems, and buds. In order to control these pests, you will want to prune the damaged parts of the plant in the fall to remove eggs potentially laid in them.

This limits adults from spreading and removes any eggs that may have been laid.

You will need to be sure that any plant residue from the affected plant is not left in the area by properly disposing of it through shredding or burying it in soil.

Step 2: Spray Residual Insecticide

During the fall, four-lined plant bugs begin to lay large group of eggs, which then hatch in spring. The nymphs will remain near their hatching site and the adults will not show themselves until your foliage has become lush, and green making direct pesticide contact difficult. For this reason, you will want to use a residual insecticide such as Supreme IT.

Supreme IT is a insecticide concentrate made with 7.9% bifenthrin to control plant bugs, such as four-lined plant bugs and 70 other type of pests. When this product has dried on your ornamentals it will protect them for up to 90 days after application. To treat specific areas on the foliage leaves then you will want to use a handheld pump sprayer.

Determine how much Supreme IT to use by measuring the square footage of the treatment area. To do this, measure the length and width in feet then multiply (length X width = square footage). To treat plant bugs, apply 0.25 to 0.5 fl. oz. of Supreme IT per gallon of water per 1,000 sq. ft. of ornamentals.

To mix, fill your sprayer with half the amount of water, pour measured amount of Supreme IT, then add the remaining half of water. Close the spray tank lid and shake until solution is thoroughly mixed.

Once your solution is evenly mixed, spray the top and bottom of ornamental leaves until wet, but not to the point of runoff. If applying Supreme IT, do not apply this product to any plants grown for consumption. Wait until treated plants are completely dry before any irrigation can occur and before allowing children, people, or pets to come into contact with treated areas.

Four-lined plant bugs and other labeled pests that make contact with the spray or its residual will have their nervous systems impacted and will die within hours.

Prevention

Once the four-lined plant bug population has been controlled, you should take on some preventative measures to keep this pest away. Listed below are some methods you can take to prevent four-lined plant bugs from coming back to your plants:

• Implementing watering practices with an inch of irrigation once per week will help to discourage four-lined plant bugs as well as revigerate plant growth from past pest activity.
• Using cultural methods such as keeping the landscape and plant area free of fallen leaves and other plant debris, tilling the soil, raking fallen leaves, and on-going pruning of leaves, twigs, branches, and other damaged plant parts will help to eliminate overwintering eggs and site of activity for adults.
• Mow when your turf has reached 3 inches in height and properly dispose of grass clipping to avoid overwintering sites for four-lined plant bugs. As well as removing grass and weeds in-between or around landscaped areas.
• Four-lined plant bugs are fast-moving pests that can be kept away with quarterly applications of Supreme IT every 90 days on your ornamentals. Preventative measures are most effective in the early fall and spring.

Key Takeaways

What are Four-Lined Plant Bugs?

• Four-lined plant bugs are a type of true bug that insert their mouthparts into plant leaves for the chlorophyll. Adult four-lined plant bugs lay eggs in the fall, and then they hatch the following spring leaving behind a trail of unaesthetic damages to plants.

How to Get Rid of Four-Lined Plant Bugs

• To get rid of four-lined plant bugs from your plants, you will need to prune any damaged leaves, stems, buds, and shoots to remove potential eggs. Afterwards, an application with Supreme IT on the top and bottom of ornamental leaves will eliminate any remaining pests.

Preventing Four-Lined Plant Bug Reinfestation

• Eliminate food and nesting site conditions for four-lined plant bugs with regular watering practices, mowing, pruning, raking, and tilling of soil. Keep with up residual insecticide applications such as Supreme IT every 90 days to repel this pest.