Hyphantria cunea, commonly known as the fall webworm, is a species of caterpillar belonging to the family Erebidae. Native to North America, this insect has been introduced to many other parts of the world, including Europe and Asia. The scientific name "Hyphantria cunea" derives from its genus, Hyphantria, and its specific epithet, cunea, which refers to its characteristic triangular shape.
The fall webworm is a highly adaptable and polyphagous pest, meaning it feeds on a wide variety of host plants. It primarily targets deciduous trees such as walnut, birch, oak, and hickory. The caterpillars construct conspicuous silken nests or webs on the branches of their food plants, which provide protection from predators and environmental factors.
The larvae of Hyphantria cunea are characterized by their variable coloration, ranging from pale yellow to dark brown, with a row of black spines down their back. They undergo several molts before reaching maturity and can cause significant defoliation if present in large numbers. However, the impact on tree health and survival is typically minimal since infestations occur late in the growing season.
As adults, the fall webworms are moths with a wingspan of around 3-4 centimeters. They are generally white with brown or black markings. The females lay their eggs in masses that overwinter, ready to hatch and begin the cycle anew the following spring.
Hyphantria cunea is considered an important pest due to its ability to defoliate a wide range of trees and adapt to various climatic conditions. However, it also serves as a food source for numerous natural enemies, including birds, wasps, spiders
