How to Get Rid of Worms in Aspen Trees

Aspen trees are towering beauties, with soft green foliage and stark white bark. They are popular in landscaping and can be found in many different regions. All deciduous trees can be attacked and defoliated by pests. One such creature is the caterpillar known as the tent caterpillar or webworm (Malacosoma disstria). In their larval, or caterpillar, state these worms build webs at the ends of tree boughs. They then drop off to become moths and fly away. The webs they leave behind contain their eggs, and can become large and unsightly. Within the web, there are large brown egg sacs surrounded by dead foliage and waste. The newborn caterpillars feed on the foliage of the aspen tree in which they were born. To get rid of these pests organically, follow a couple easy steps.

Things You'll Need

• Rake/broom
• Beneficial wasps
• Sunflowers
• Bird feeder
• BT spray
• Neem oil spray

Instructions

1. When you see webs in the branches of your aspen tree, it's evidence of webworms. Use a rake or broom to knock the webs and eggs sacs out of the tree to destroy them. These webs hold future or newborn webworms, so you're destroying future generations of the pests, and protecting your tree from damage or defoliation.

2. Encourage natural predation of webworms to kill the current infestation and prevent future generations. Plant sunflowers around your aspen trees and in your yard, to attract beneficial wasps. Hang bird feeders from the trees to attract birds, which will eat the caterpillars and the moths they become. Beneficial wasps can also be purchased at your local garden supply shop. Introducing these predators will affect the population of webworms in your aspen tree.

3. Use chemical sprays to destroy webworms. Purchase and spray with Bt spray, which infects caterpillars and kills them. This organic spray will not harm plants or other animals like many pesticides. Since butterflies begin as caterpillars, though, it may reduce your butterfly population. Back this up by spraying with neem oil, which is another organic pesticide. Neem oil has a better chance of affecting other insect life, though and may also kill your beneficial wasps.

Tips & Warnings

• Webworm webs usually appear in late summer.

• Worms cannot actually kill a healthy aspen tree. They will defoliate it, and their webs are unsightly.

• Pesticide use can kill beneficial insects, and may poison animals in the area.

References

• "Forest Tent Caterpillar;" U.S. Forest Service; 1981.
• "Better Homes and Gardens;" Stop Fall Webworms the Organic Way
• Aspen Tree