The four-lined plant bug feeds on over 250 plant species, many of which are herbaceous. The woody ornamental plants that are sometimes fed upon by this insect are included in this guide. The four-lined plant bug overwinters as eggs which are inserted into the tender shoots or water sprouts of certain host plants. Females use their ovipositor to cut a slit in the tissue of the plant, into which the eggs are inserted. Clusters of eggs may be seen when leaves drop in the fall. Egg hatch may occur in late April or May in Massachusetts. Nymphs develop over the course of approximately 30 days. The color of the nymph varies as it matures, from bright red to bright yellow/orange and they have short developing wing buds during this life stage. Some eggs may hatch late, leading to an extended period over which nymphs are present. After 5 nymphal instars (molting in between each), the insect matures into an adult which is also brightly colored - forewings are bright yellow or bright green with four distinct black lines. Adults are approximately 3/16th of an inch long with fully developed wings and present for approximately one month. Adults feed on the upper surface of host plant leaves, but may be easily disturbed and quickly fly away or hide from view. There is one generation per year.
Feeding injury from both the nymphs and adults causes black or brown disease-like spots to form on the foliage of numerous hosts. The injured areas may turn black or appear translucent. After a few weeks, the necrotic tissue may drop from the plant leaving small holes behind. Some plants can outgrow the damage caused by this insect in the same season.
Scout for tiny yellow spots that may indicate early spring feeding by this insect, prior to the necrotic tissues turning brown or black or dropping from the leaves. The insects themselves, due to their hiding behavior, may be difficult to detect. Try sweeping the foliage on plants suspected to have four-lined plant bug damage with a net to catch them.
Prune out and destroy eggs laid in tender shoots or water sprouts prior to hatch in the spring; note that eggs can be extremely difficult to see and locate. On herbaceous hosts, thoroughly cutting back growth at the end of the season and disposing of that material may help remove overwintering eggs.
Natural enemies of the four-lined plant bug are not well known at this time. A predatory wasp larva, Cirrospilus ovisugosus, is known to feed on four-lined plant bug eggs, and may be capable of destroying entire egg clusters. A certain species of jumping spider, Phidippus clarus, has also been reported as a possible biological control agent of the four-lined plant bug (Borden and Dale, 2016).
Acephate (NL)
Acetamiprid (L)
Beauveria bassiana (NL)
Bifenthrin (NL)
Carbaryl (L)
Chlorpyrifos (N)
Chromobacterium subtsugae (NL)
Clothianidin (NL)
Cyantraniliprole (NL)
Cyfluthrin (NL)
Deltamethrin (L)
Dinotefuran (NL)
Flonicamid+cyclaniliprole (N)
Gamma-cyhalothrin (L)
Horticultural oil (L)
Imidacloprid (L)
Insecticidal soap (NL)
Isaria (paecilomyces) fumosoroseus (NL)
Lambda-cyhalothrin (L)
Neem oil (NL)
Permethrin (L)
Spinetoram+sulfoxaflor (N)
Tau-fluvalinate (NL)
Active ingredients that may be applied systemically include: acephate (injection), acetamiprid (injection), clothianidin (soil drench), cyantraniliprole (soil drench, soil injection), dinotefuran (soil drench), imidacloprid (soil drench), and neem oil (soil drench).
Make insecticide applications after bloom to protect pollinators. Applications at times of the day and temperatures when pollinators are less likely to be active can also reduce the risk of impacting their populations.
Note: Beginning July 1, 2022, neonicotinoid insecticides are classified as state restricted use for use on tree and shrub insect pests in Massachusetts. For more information, visit the MA Department of Agricultural Resources Pesticide Program.
