If you've ever stepped outside to admire your hydrangeas, only to spot a bunch of creepy-crawlies munching away on your plants, you know the frustration. We've all been there—one minute your flowers are thriving, and the next, they're covered in a bunch of tiny aphids. But before you panic and grab the pesticide, take a deep breath. There's a better way to handle these pesky invaders.
Whether it's tiny spider mites on your shrubs or tent caterpillars taking over your trees, pests on your landscape plants can generally be categorized based on how they damage your plants: sucking pests, chewing pests, and boring pests. In this blog, we'll focus on the first two categories and how to deal with them, leaving the silent destroyers—boring pests like beetles and the emerald ash borer—for the next installment.
Sucking Pests: The Tiny Vampires of the Plant World
Sucking pests feed on plant sap, which causes wilting, curled leaves, and sometimes a sticky residue that encourages the growth of mold. Here's how to tackle the most common sucking pests:
Aphids
Host Plants: Various shrubs and trees
Appearance: Soft-bodied, around ¼ inch long and vary in colors like green, yellow, and black.
Damage: Aphids suck out plant sap, leaving a sticky substance that attracts mold.
Control: Inspect plants regularly and wash off light infestations with a strong stream of water. For larger problems, use beneficial nematodes, horticultural oils and/or products like malathion.
Scale Insects and Mealybugs
Host Plants: Various woody ornamentals and trees
Damage: These pests appear as waxy lumps on stems or leaves and move about the host plant while feeding.
Appearance: Small insects with a protective covering over soft bodies. Various colors like red, black and white.
Control: Prune heavily infested areas and treat with horticultural oils or sprays. Most vulnerable to insecticide treatments before they mature and their thick coverings form.
Spider Mites
Host Plants: Various woody ornamentals and trees
Damage: Causes stippling and browning on leaves.
Appearance: Spider mites are so small they are extremely hard to see with the naked eye. The adults have eight legs and no wings or antennae.
Control: Regularly inspect plants, especially during dry spells, and wash off light infestations. Severe cases may require insecticide treatments.
Lace Bugs
Host Plants: Azalea, laurel, hawthorn, apple, and others
Damage: These pests feed on the undersides of leaves, causing yellowing spots.
Appearance: Lace bugs get their name from the lacelike covering behind their head and wing covers. They are partly transparent and one-eighth to ¼ inch long.
Control: Treat with horticultural oils and inspect weekly to catch infestations early. Early spring is the best time to treat before these can spread.
Whiteflies
Host Plants: Gardenia, crape myrtle, azalea, and more
Damage: They cause wilting and promote mold growth.
Appearance: Tiny, gnat-like insects with matte white wings and yellow bodies. You'll know you've got them when you disturb an infested plant, and a cloud of tiny white flies takes off.
Control: Monitor plants for infestations and apply products containing acephate or horticultural oils.
Thrips
Host Plants: Roses, sunflowers, chrysanthemums, tomatoes, peppers and more
Damage: Discoloration by puncturing plants and sucking out the sap with their mouthparts. They can also leave behind silver streaks and black spots on your plants. They're most problematic in the warmer months and can damage flowers, fruits, and foliage.
Appearance: Slender, cigar-shaped insects that are up to 1/10 inches long and vary in colors from yellow to black.
Control: Use insecticides labeled for thrips, as they may be resistant to some treatments. Encouraging natural enemy populations, like some wasps, are an effective way to keep thrips in check.
If you are currently struggling with the pests listed above infesting your landscape and causing lawn issues, reach out to your local lawn care professional for more information and the best options for your and your lawn.