Ash Plant Bug
Attacks:
White, green, and blue ash species
What you will see:
- Yellowish white spots “stippling” on leaves
- Large brown areas on leaf
- Leaf drop and/or deformation of the leaf
- Small black spots on bottom side of leaf
- Active black and red nymphs in May and July
Life cycle:
- Eggs overwinter on twigs and branches
- Eggs hatch at bud break in the spring
- First generation feed for 3-4 weeks
- Mate and lay eggs that hatch in seven to ten days
- Second generation from July through August
- Eggs laid in July and August hatch the following spring
Cultural practices:
- Increase nectar sources for predators by planting flowering plants nearby
- Fertilize according to Arborist recommendation
- Mulch with Prescription Organic Matter©
Chemical practices:
- Ash plant bug is susceptible to both systemic and topical insecticides. Please consult with your Arborist for recommendations.
Additional Ash Plant Bug Information:
Plant bugs are a group of insects that eat the foliage of trees by piercing the leaf tissue with needle-like mouthparts. They then eat the sap from the leaves. The most common plant bug in Minnesota is the ash plant bug and the honeylocust plant bug. They feed on all variety of honeylocust planted in urban areas. The ash plant bug feeds on green, white and black ash. Plant bugs rarely seriously injure mature, growing trees, however they do create some damage to the foliage. If the damage is severe, it impacts the health of young, newly planted trees.
Ash plants are oval and are as long as 1/8" as nymphs and ¼" in length as adults. Nymphs are pale yellow or red to brown and black and look like large aphids. Adults are similar in the way they look, but are much more slender and have wings on their abdomen. Ash plant bug nymphs can create black sticky specks of feces on the underside of the infested leaves.
Ash plant bugs can reproduce up to two generations per year. Eggs are hatched in the spring after the ash leaves expand. First generation adult bugs show up in June to mate and deposit eggs on midribs of leaves. The nymphs hatch from these eggs and turn into adults by July or August. Adults lay their eggs on twigs, bud scales, and safe places throughout the bark where the eggs in winter. Second generation adults stay active until the first hard frost. Second generation ash plant bugs are active for longer, but first generation cause more damage to leaves.
The expanding leaf tissue in the spring is more sensitive to the saliva that is injected into the leaves, while the ash plant bugs eat. This quickly damages the leaves.