Protect Your Landscape from Insect Pests

Insect pests cause significant damage to gardens and landscapes. In our service area on Chicago’s North Shore and Southeastern Wisconsin, we see the evidence of this every day. Although not all insects are harmful, the damage potential from insect pests can be huge. In fact, insects cause more damage to your garden than any other type of pest.

Once established, the cost to get rid of insect pests can be significant. The resulting damage can ruin the appearance of your home landscape. So, be proactive! Keep a close eye on your plants and trees to prevent an infestation – look for signs of damage and disease. Plants that are stressed due to drought are especially susceptible to damage. Also, their growth can be adversely affected.

Insects can harm any part of a plant and at any stage of its development. In serious cases, pests may even kill plants. Sucking insects may transmit disease from infected plants to healthy plants. Even trees can be subject to harm and complete loss, due to insect pests. For example, the emerald ash borer has done significant damage in our area. The beetle has contributed to tree loss by eating the tissue under the tree bark.

Be vigilant in checking plants and taking action before things get out of control. Early detection and treatment can be the difference between saving and losing a prize specimen. Keep in mind that effective treatments, such as chemical insect sprays, may also harm or kill beneficial insects. To avoid this, it’s a good idea take advantage of expert resources:

  • Contact Chicago Botanic Garden’s Plant Information Service for helpful information and advice.
  • Invest in a bug ID book or visit the website links below to see photos and learn about insect pests.
  • Call us at Van Zelst for help in identifying and treating your garden for insect pests: 847-243-6587.

Get to Know these 3 Insect Pests

The number of pest species is large! Become familiar with our top 3 insect pests, so you can identify them and protect your plants from damage.

Two-spotted spider mite

Latin Name: Tetranychus urticae
Description: Small, tiny, wingless creature that is difficult to see without a hand lens or magnifying glass
Where they live: Undersides of leaves
Plants affected: Annuals, perennials, trees, and shrubs
Harm to the plant: Sucks the fluid from the leaves which creates small dots or specks – also creates a fine network of webs that cover stems and leaves
Discouraging damage: Keep plants well-watered – Chemical control only as last result
Spider Mites crawling on webs (Photo credit: R. Lopez).

Japanese Beetles

Latin Name: Popillia japonica
Description: Metallic green insects that emerge in July and feed for 4-6 weeks
Where they live: On plants, grubs live in grass
Plants affected: Over 300 types of plants
Harm to the plant: Chew on plants leaves and flower tissue, can create extensive damage and leaves will fall from the plants, grubs feed on the roots of grass causing brown patches
Discouraging damage: Hand pick the beetles or knock them into a bucket of soapy water – best to do this in the early morning
Japanese Beetle.

Aphids

Latin Name: Aphidoidea
Description: Small, soft-bodied insect – reproduces many times a year – easy to spot in clusters, usually wingless
Where they live: On plants
Plants affected: New succulent shoots, buds and leaves, perennials, annuals, shrubs, trees, vegetables
Harm to the plant: Leaves and stems can become yellow, distorted or curled – produce honeydew secretion which can cause growth of sooty mold (a harmless black fungus)
Discouraging damage: Spray plant with water to knock them off – insecticidal soap can be used with caution
Aphids.

Helpful Resources about Insect Pests

Identify Insect Pests and Protect Your Landscape

Insect pests cause significant damage to gardens and landscapes in our area. Be proactive – learn about insect pests, monitor your garden for unwanted visitors, and take action to prevent infestation and damage to your special landscape.

Call the experts at Van Zelst for information and assistance with insect pests: 847-243-6587.

Be on the lookout for…

Viburnum leaf beetle could be the next nuisance insect in the same vain as Japanese beetles.  One of the most popular and easiest to grown shrubs is the Arrowwood Viburnum (Viburnum dentatum), which means it’s fairly easy to find one in almost every landscape.  The Viburnum leaf beetle larvae and adults will feast on the foliage of Viburnums; quickly defoliating it.  After several years of defoliation your viburnum can die.  The adult beetle will then lay it’s eggs on the stems to make it an easy perennial pest, year after year!

What to look for and how to get rid of this pesky pest!

Once viburnums have dropped their leaves in fall, look for egg masses along the undersides of the twigs. Prune out and discard any damaged branches or twigs. Do not compost this debris for mulch.

Viburnum Leaf Beetle, egg masses on twig
Viburnum Leaf Beetle, egg masses on twig

In late spring and early summer, look for small holes that skeletonize the leaves between the veins. On the underside of the leaves, you might see tiny, yellow-brown caterpillars, some with spots. Destroy any damaged leaves that drop.

Viburnum Leaf Beetle Larvae
Viburnum Leaf Beetle Larvae

A few weeks after hatching, the larvae drop to the ground and burrow into the soil to pupate. In about six weeks, the adult beetles emerge, feed on the leaves and lay eggs to start the cycle all over again. The 1/4- to 3/8-inch long, golden-brown beetles look shiny in the sun.

Adult Viburnum Leaf Beetle
Adult Viburnum Leaf Beetle

Highly susceptible:

  • V. dentatum: Arrowwood viburnums
  • V. nudum:  Possum-haw, smooth witherod viburnum
  • V. opulus: European cranberrybush viburnum
  • V. opulus var. americana (syn. V. trilobum): American cranberrybush viburnum

Susceptible:

  • V. acerifolium: Mapleleaf viburnum
  • V. lantana: Wayfaring tree, Mohican viburnum
  • V. sargentii: Sargent viburnum

Moderately susceptible:

  • V. burkwoodii: Burkwood viburnum
  • V. carlcephalum: Carlcephalum viburnum
  • V. cassinoides: Witherod viburnum
  • V. lentago: Nannyberry viburnum
  • V. prunifolium: Black-haw viburnum
  • V. rhytidophylloides: Lantanaphyllum viburnum

Most resistant:

  • V. carlesii: Koreanspice viburnum
  • V. juddii: Judd viburnum
  • V. plicatum and V. plicatum var. tomentosu: Doublefile viburnum
  • V. rhytidophyllum: Leatherleaf viburnum
  • V. sieboldii: Siebold viburnum

Not sure what to do, then contact one of our professional horticulturists to help assess the problem.