Tree Pests to Watch Out For:
❶ Asian Citrus Psyllid
This tiny gray-brown insect is a threat to citrus trees, and has affected various regions all around the world. Their most common targets include orange, tangerine, lemon, and kumquat trees. While it feeds, it injects a toxin into the plant tissues, causing leaves to curl up, discolor, and even turn black. They also carry and transmit a disease called “citrus greening”, also known as “huanglongbing” (HLB). It is one of the most fatal citrus tree diseases.
❷ Japanese Beetles
Accidently imported from Japan in a shipment of irises over 100 years ago, this beetle feeds on more than 400 plant species in the United States. Their feasting leads to skeletonized foliage. Some of their favorite targets include pin oak, linden, roses, hibiscus, grapes, raspberries, crabapples, crape myrtle, sassafras, Japanese maple, and Norway maple. Although they rarely kill trees, they can take out entire lawns and gardens.
❸ Asian Longhorned Beetle
Similar to the Japanese beetle, this beetle was first discovered not too long ago in New York. They are highly destructive since they tunnel into trees and cut off their water and nutrient distribution systems. Mid-to-late summer and fall are prime seasons for Asian longhorned beetles. Common targets include birch, willow, horse chestnut, elm, goldenrain tree, katsura tree, and maple.
❹ Hemlock Wooly Adelgid
This highly invasive and damaging tree pest has killed thousands of Eastern and Carolina Hemlock trees in just the past decade. The most distinctive sign of hemlock wooly adelgid infestation is an accumulation of white masses at the base of needles on Hemlock trees.
❺ Emerald Ash Borer
Imported from Asia and first discovered in Detroit 15 years ago, this bright metallic-green beetle is a devastating tree pest that targets solely ash trees. Their larva bore deep into the tree bark and feed underneath, which creates tell-tale L-shaped holes in the trunk. This activity interrupts the tree’s ability to distribute water and nutrients, which leads to crown dieback and bark splitting.