Are Four-Lined Plant Bugs Attacking Your Plants?
The rains brought the insects en masse this year! What’s eating your garden?
Along with the heavy spring rains have come a multitude of disease and pest issues. They seem to have exploded over the last few weeks! One insect we’ve seen crop up en masse in landscapes across Dallas is the four-lined plant bug. If you’ve noticed clusters of circular brown spots on plant leaves, you may be under attack by this small garden culprit.
An adult four-lined plant bug.
The Life Cycle
The four-Lined Plant Bug, Poecilocapsus lineatus, has both a nymph stage and an adult stage. It only has one generation per season, which does help cut down on how much damage it does. The nymphs feed from late April through May, then find a mate, lay eggs, and die off. The eggs overwinter until the following spring when they hatch into nymphs then grow into the adult insect after about 30 days. It is the nymphs that do the most damage to plants, sucking moisture out from the underside of leaves. As adults, they use mouthparts to inject digestive liquid into the leaf, then suck the nutrient rich juices from the leaves of your plants, leaving the pock-marked and shriveled.
Hatched eggs of the four-lined plant bug.
You’ll first notice uniform circular patches of damage on plant leaves. These circles then turn dark brown, giving the leaves a scorched appearance. While they often frequent aromatic herbs like mint, oregano, sage and sweet marjoram, basil and thyme, they will also damage some ornamental annuals and perennials. If you have shasta daisy in your garden you’ll often find them a spring-time target of the four-lined plant bug.
While the leaf damage looks pretty bad, it’s not long lasting and plants typically outgrow the damage. Simple applications of insecticidal soap or neem oil can help minimize the infestation and subsequent damage.
As with most garden pests, prevention is key! Be sure to do a good late-winter cleanup in the garden to remove old leaf litter; as this is where eggs of the four-lined plant bug overwinter.