Tarnished Plant Bugs: Identification, Prevention, and Control

The Tarnished plant bug is a common sap-feeding insect which attacks a wide range of plants. Bean, beet, cauliflower, cabbage, chard, celery, cucumber, potato, turnip, salsify, and dill, apple, peach, pear, blueberries and most other deciduous and small fruits. Strawberries are one of their favorites.

It can cause considerable damage to vegetables and fruits by puncturing young fruits before they mature. These damaged areas do not develop along with the rest of the fruit/vegetable, resulting in misshapen fruit . The damage may range from slight deformation to complete loss. Adults and nymphs both inject poison into young stems, buds, and fruit. It sucks on blossom and stems.

They carry fire blight disease and infect plants as they feed. Black spots and pitting can be seen on the stem, tips, buds, and fruit.

The tarnished plant bug overwinters as an adult in leaf debris and other protected areas.

Adults are recognized by their greenish-brown body marked with yellowish – black dashes and a characteristic small yellow-tipped triangle behind the head.

Adults become active in April and begin egg laying in weeds. The tiny nymphs are slender, pale green insects that resemble aphids. However, aphids have a pair of cornicles (tail pipe-like tubes on top of their underside) while tarnished plant bugs do not. The nymphs turn brown. The entire life cycle is completed in slightly more than a month with several overlapping generations each season.

Most damage takes place just after petal fall.

Control of Tarnished Plant Bug

Found to be resistant to many forms of insecticides, Neem Oil has proven highly effective against the tarnished plant bug. It prevents the larvae from developing normally and is also a good alternative for later larval stages. Neem degenerates rapidly in nature and needs to be reapplied frequently.

Kaolin Clay acts as a barrier that repel insects and disguises the host plant by coating it with a harmless white film. Insects, unable to recognize their favorite plants simply move on. It is used on fruit trees, but works well in vegetable gardens as well.

Bacillius thuringiensis [Bt] is highly effective against the larvae stage and should be applied as soon as the larvae are first noticed or suspected.

Beauveria bassiana a naturally occurring fungus that acts as a parasite on various insect species including the tarnished plant bug.

bifenthrinFor ornamental Plants Only.

Pyrethroids and Pyrethrins such as Cyfluthrin

Thiamethoxam. “…a broad-spectrum, systemic insecticide… absorbed quickly by plants and transported to all of its parts, including pollen, where it acts to deter insect feeding…. The compound gets in the way of information transfer between nerve cells … in the central nervous system, and eventually paralyzes the muscles”.[Wikipedia – Thiamethoxam]

Inter-plant Garlic amongst susceptible plants. Garlic is known to deter the tarnished plant bug.