The four-lined plant bug (Poecilocapus lineatus) removes plant’s chlorophyll via their piercing-sucking mouthparts. They also secrete a toxin in their saliva that digests the components responsible for holding the plant cells together that leaves a hole in the plant’s epidermis. This feeding produces white, dark, or translucent spots the plant’s leaves, which can run together forming large blotches. Leaves can turn brown, curl-up and ultimately fall off. If feeding occurs on new growth, wilting may result.
Damage that the four-lined plant bug inflicts can be misidentified as a fungal disease spots because of the similar appearance and timing. Many times the bug isn’t seen during scouting, as when they are disturbed, the four-lined plant bug will drop to the ground or will hide on the other side of the stem. These are the same tactics asparagus beetles employ.
How to mitigate the damage:
These bugs do like a wide variety of plants, so be aware that the damage may look just a bit different on different plants. Unless the attacked plant is very small or having the new growth chewed, most plants will pull though with some damage. Scout the damaged plant at different times of the day. Sometimes bugs don’t wake up early in the morning!
Have a cup of soapy water ready for when you do see one. They are easy to catch, place cup below them, wave your hand near them and they will cannonball into the soap water. No squishing required. Neem oil can also be used for bad cases.
During the fall, the banana shaped eggs are placed at right angles in vertical slits along the plant’s stem. The eggs will over winter and hatch in May to late-June. Therefore, removing the dead plant material at the end of the season will lower next season’s attacks.
© Ilex ~ Midwestern Plant Girl