The ash plant bug (Tropidosteptes amoenus) belongs to a group of insects called “True Bugs” which are characterized by lacking hard wing covers like those found on beetles. They have an inverted triangle on their backs which helps identify them. They can be found on the bottom side of ash leaves in June.
- Yellow stippling on leaves
- Small black dots of excrement
- Heavy feeding can kill leaves
Cultural or Non-chemical Controls:
- Well-watered trees tend to have fewer ash plant bugs and can withstand more feeding without dropping leaves.
- In June wash the bugs off the tree using a forceful jet of water. By July this method will be ineffective as the adult bugs have wings and will return to the trees.
- Insecticidal soap applied at 10 day intervals can stop heavy outbreaks. As this insect doesn't harm otherwise healthy trees, chemical control is rarely needed.