Destructive Landscape Pests: Identifying Leaf Sucking Insects

Are leaf eating insects damaging your trees? Sometimes it can be hard to detect, but be aware that this can be a very real problem as it can quickly turn into an infestation. Here are some leaf sucking insects that can damage your tree leaves.

Damaging Leaf Sucking Insects

Aphids are insects that damage trees by sucking the juices out of the plant tissue mainly the leaf. Aphids can generally be found on the underside of the leaf. Although aphids do not eat the leaves and cause holes on the leaves, they do produce a gradual change in the color of the foliage. A tree or plant with an infestation of aphids will show symptoms of Chlorosis, which is a sticky residue found in and around objects near the aphid infestation. This is the excrement (honeydew) from the insect. 

Leafhoppers are wedge-shaped insects, usually green in color that hop when disturbed. These leaf sucking insects get sap from leaves, causing them to curl and die. Young, wingless leafhoppers resemble the winged adults. 

Spider Mites attack evergreens and can often go unnoticed because of they’re microscopic size. To check for them, one can hold a white sheet of paper under a branch and shake the branch. A close look will reveal these very tiny, red mites on the paper. A heavy infestation will cause a continued loss of color in the tree. Mites are a common problem on junipers and spruce trees.

Destructive Scale Insects

Lecanium Scale is a group of insects that vary greatly in size, color, and shape. These scales infest a wide variety of shade trees, feeding on the sap of the host plant. This stress may cause a severe dieback of the wigs and branches. The crawlers are usually present in late July. 

Oystershell Scale is a scale insect, shaped like an oystershell, and very easily seen when foliage is absent in winter. Crawlers or young scales appear in summer, and can be found on many shade tree species. 

Pine Needle Scale is one of the most common and serious pests of pines. Its appearance is like that of white powder or specks covering the needles. The crawlers, as with all scales, suck the juices from the needles, causing them to turn yellowish, then brown. Heavy infestations can lead to the death of a pine tree. 

Euonymus Scale is a generally difficult to detect until it has caused serious damage on the tree. One symptom of a light attack is the occurrence of yellowish or whitish spots on leaves and stems. White, hardened scales or specks will develop when heavy infestation occurs. 

Fletcher Scale is common on arborvitae and taxus trees. On arborvitae, the foliage is damaged, while the stems and branches will be damaged on the taxus. Fletcher Scale infestation causes visible damage or injury to arborvitae, but infestation on the taxus causes needle drop, and heavy infestations will leave a crust of sooty mold on the twigs and needles. Young Fletcher Scale leaf sucking insects feeds by obtaining the juices from the plant. Take closer look at your trees and shrubs this season to detect if leaf discoloration is due to these leaf sucking insects. Your local Spring Green professional offers a two step tree program* to nourish and protect your trees and shrubs this season!