What is Cankerworm?

Cankerworm, also known as inchworm or measuring worm, is a type of caterpillar that belongs to the family Geometridae. These caterpillars are named for their unique way of moving, which resembles the motion of an inchworm or a measuring tape. Cankerworms are found in various parts of the world, including North America, Europe, and Asia. They are known for their voracious appetite and can cause significant damage to plants and trees.

Life Cycle of Cankerworm

The life cycle of a cankerworm consists of four stages: egg, larva, pupa, and adult. The adult female cankerworm lays her eggs on the branches of trees in late summer or early fall. These eggs overwinter and hatch in the spring when the weather becomes warmer. The newly hatched larvae, also known as caterpillars, start feeding on the leaves of trees and plants.

Feeding Habits of Cankerworm

Cankerworms are known for their voracious appetite and can defoliate entire trees if left unchecked. They primarily feed on the leaves of deciduous trees, such as oak, maple, and elm. The caterpillars use their strong jaws to chew through the leaves, leaving behind a characteristic pattern of holes. As they grow, cankerworms molt several times, shedding their old skin and growing a new one.

Damage Caused by Cankerworm

The feeding habits of cankerworms can cause significant damage to trees and plants. When a large number of caterpillars feed on the leaves, it can lead to defoliation, weakening the tree and making it more susceptible to diseases and other pests. Severe defoliation can even lead to the death of the tree. Additionally, the presence of cankerworms can also impact the aesthetic value of landscapes and gardens.

Control and Management of Cankerworm

Controlling cankerworm populations is essential to prevent damage to trees and plants. There are several methods that can be used to manage cankerworm infestations. One common method is the use of insecticides, which can be applied to the leaves to kill the caterpillars. However, this method may have negative impacts on other beneficial insects and the environment.

Natural Predators of Cankerworm

Cankerworms have natural predators that help in controlling their populations. Birds, such as chickadees, sparrows, and warblers, feed on the caterpillars, reducing their numbers. Other predators include spiders, wasps, and beetles. These natural enemies play an important role in maintaining the balance of ecosystems and preventing cankerworm outbreaks.

Preventing Cankerworm Infestations

Preventing cankerworm infestations is crucial to protect trees and plants. One preventive measure is the use of sticky bands or barriers around the trunks of trees. These bands trap the caterpillars as they crawl up the tree, preventing them from reaching the leaves. Regular inspection and early detection of cankerworm eggs or larvae can also help in preventing infestations.

Integrated Pest Management for Cankerworm

Integrated Pest Management (IPM) is a holistic approach to managing pests, including cankerworms, in a sustainable and environmentally friendly manner. IPM involves the use of multiple strategies, such as cultural practices, biological control, and chemical control, to minimize the use of pesticides. This approach aims to reduce the impact on non-target organisms and promote long-term pest management.

Signs of Cankerworm Infestation

There are several signs that indicate the presence of a cankerworm infestation. One common sign is the presence of chewed leaves with characteristic patterns of holes. Another sign is the presence of caterpillars crawling on the branches or hanging from silk threads. Severe defoliation of trees and the presence of droppings or frass are also indicators of a cankerworm infestation.


In conclusion, cankerworms are caterpillars that can cause significant damage to trees and plants. Their voracious appetite and feeding habits can lead to defoliation and weaken the affected plants. It is important to implement control and management measures to prevent cankerworm infestations and protect the health of trees and landscapes. Integrated Pest Management practices can be employed to minimize the use of pesticides and promote sustainable pest management.