Resource Number: 3428
Title: Caterpillars on the Foliage of Conifers in the Northeastern United States
Description: Coniferous forests are important features of the North American landscape. In the
Northeast, balsam fir, spruces, or even pines may dominate in the more northern forests.
Southward, conifers still may be prevalent, although the pines become increasingly
important. In dry, sandy areas, such as Cape Cod of Massachusetts and the Pine Barrens
of New Jersey, hard pines abound in forests composed of relatively small trees. Conifers
are classic symbols of survival in harsh environments.
Forests of conifers provide not only beautiful scenery, but also livelihood for people.
Coniferous trees are a major source of lumber for the building industry. Their wood can be
processed to make paper, packing material, wood chips, fence posts, and other products.
Certain conifers are cultivated for landscape plants and, of course, Christmas trees. Trees of coniferous forests also supply shelter or food for many species of vertebrates, invertebrates, and even plants. Insects that call these forests home far outnumber other animals and plants.
Because coniferous forests tend to be dominated by one to a few species of trees, they are
especially susceptible to injury during outbreaks of insects such as the spruce budworm,
Choristoneura fumiferana, the fall hemlock looper, Lambdina fiscellaria fiscellaria, or the
pitch pine looper, Lambdina pellucidaria. Trees that are defoliated by insects suffer reduced
growth and sometimes even death.
Trees stressed by defoliation, drought, or mechanical injury, are generally more susceptible
to attack by wood-boring beetles, diseases, and other organisms. These secondary pests
also may kill trees. Stress or tree death can have a negative economic impact upon forest
industries. In addition, severe injury has other, often less obvious, impacts on the health
and the inhabitants of forests. For example, defoliation can destroy the food and the habitat
of insects and other animals, causing their decline or possibly extirpation. Defoliation and
tree death also lead to elevated temperature in the soil and the water, which has additional
negative ramifications.
Most caterpillars and other insects, however, are not pests. Many provide essential food for
animals and plants, recycle nutrients, or destroy noxious insects and plants. Furthermore,
studies of forest insects have been instrumental in developing the fields of ecology, animal
behavior, and environmental health.
In this manual, we furnish descriptions and photographs of caterpillars, as well as
information on life history, to assist foresters, extension agents, educators, students,
conservationists, and others who wish to identify and understand the caterpillars that eat
the foliage of conifers.
Last Updated: June 11, 2019
Domain(s)/Area(S):
- Entomology
Locations: