UACES Facebook Common Insect Problems


Forest Insects

Arkansas' forests are home to many different tree species that provide tremendous and diverse resources to the people of our State. However, those same trees can be hosts to many different problematic forest insects. Tree insect problems can range from a nuisance concern to an epidemic outbreak. They can occur in remote natural woodlands, forest plantations, in a park, or in someone's backyard. The University of Arkansas Division of Agriculture has Extension foresters and pest specialists dedicated to helping to identify insects, assess problems, and provide potential solutions to limit insect damage to trees. 

 

SPB Spot

Southern Pine Beetle Damage

IPS gallery

Ips Gallery in a Pine Log

ROB damage

Red Oak Borer Damage to a Oak Log

Tip Moth Damage

Tip Moth Damage to a Pine Plantation

Key Tree Types in Arkansas' Forests and Common Insects that Feed on Them:

Pines -

Pines are valuable for their utilization in the pulp and timber industry. They provide habitat for wildlife. They are important environmentally for water quality, carbon sequestration, and other values. There are two primary pines in Arkansas: Loblolly and shortleaf pine (Pinus teada and Pinus enchinata).

Common Pine Insects: 

 

Insect Description

Ips beetle

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 IPS beetle (Ips avulsus, Ips grandicollis, and Ips calligraphus)

  • Next to southern pine beetle (SPB), Ips beetles kill more pine timber in the South than any other insect. In Arkansas, Ips beetles are more prevalent than SPBs most years. Ips beetles most often attack injured, dying or recently felled trees or logging debris. 
  • Adult beetles are dark red-brown to almost black. One-eighth to one-fifth of an inch long. They can be separated from other bark beetles by their "scooped out" posterior, with 4 to 6 spines on each side. The first signs of an injury from Ips is almost always reddish-brown boring dust present in bark crevices or dime-sized, reddish-brown pitch tubes extending from the tree trunk. 
  • The best control is prompt removal and utilization of infested trees making sure to destroy bark and other harvesting debris.

Southern Pine Beetle

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Southern pine beetle (Dendroctonus frontalis)

  • The southern pine beetle (SPB) is one of the most destructive insects to pine timber in the South. 
  • The adult is shortlegged, reddish-brown to black, and about one-eight of an inch long. The front of its head is notched with a rounded rear section. Adult beetles bore directly into the bark, creating a pitch tube resembling popped popcorn. Adult beetles construct winding S-shaped galleries under the bark that girdle the tree. 
  • Natural predators normally keep populations in check. Common integrated pest management may include: rapid salvage and utilization of infested trees, piling and burning of infested materials, and cut and leave (May through October).

Nantucket Pine Tip Moth

Tip Moth

Nantucket pine tip moth (Rhyacionia frustrana)

  • Tip moths are meristem feeders, which means they attack the buds and shoots of pine trees. They can be problematic in young developing pine stands, by killing primary buds, causing pine saplings to become bushy and retarding height growth. They can also cause deformation in main stems of trees as they develop. 
  • Young larvae are cream colored and mature larvae are light brown to orange. The moths are covered with gray scales with white patches on the forewings. Larvae bore into the buds and shoots of young pine trees. Often an infected bud will easily snap from a tree. 
  • Control is performed using chemicals, but is usually not recommended except for in seed orchards, Christmas tree plantations, or nurseries.

Pales Weevil

Pales Weevil

Pales weevil (Hylobius pales)

  • One of the most serious threats to recently planted pine stands in the South, especially on cutover sites. There have been recorded cases of up to 90% mortality from infestations. 
  • Adult weevils are oblong, black to reddish-brown, and about one-half an inch in length. The wing covers have small scattered, yellowish hairs. Adult weevils often feed on the bark of seedlings and their twigs. Small irregular patches are common. Heavy feeding girdles stems, causing mortality. 
  • The best control is preventative. It is best to delay planting for one growing season in areas harvested after July. Seedlings can also be treated with a registered insecticide.

Pine Webworm

Pine webworm (Tetralopha robustella)

  • Usually attacks one and two year old seedlings, but can infest larger trees. Rarely is defoliation at a level to cause mortality, but it can impact seedling growth. 
  • The adult moth is dark to medium gray, with very dark forewings. The larvae are light gray with darker tan stripes along the body and usually three-quarters of an inch in length. Large areas of frass and excrement pellets in a web of silken webbing is usually the first indication of injury. 
  • Hand-picking can be effective means of control.

 

Oaks -

Oak trees provide multiple benefits. They provide wood for pulp and specialty timber products, such as flooring and cabinetry. They also provide essential wildlife habitat for many animals.

Common oak insects:



Insect Description

Red Oak Borer

ROB

Red oak borer (Enaphalodes rufulus

  • In the early 2000's the red oak borer severely impacted thousands of acres of aging upland hardwood areas in north Arkansas. The insect can cause serious degrade in high value oak timber. There is also a white oak borer. 
  • Adult borers are light brown, robust beetles with long antennae. The borer is usually around one-inch in length. Initially tiny pin-holes with fine frass are present, later entrance holes become larger. Interior tunnels are half and inch wide and six to ten inches long. 
  • Preventative maintenance is best for control. Maintaining high vigor trees will prevent excessive damage in most years.

Variable Oakleaf Caterpillar

Variable oakleaf caterpillar (Heterocampa manteo)

  • A defoliator that feeds on all species of oaks, but mostly white oaks. In outbreak years, can effect tree growth and vigor. Rarely do outbreaks last long enough to cause mortality. 
  • As the name implies, the caterpillar color is variable but generally yellowish green with a narrow white stripe down the center of the back. The adult moth is ashy gray with three dark wavy lines across forewings. Leaves are "skeletonized" by young larvae and devoured by older larvae. Usually occurs in June/July and August to October. 
  • Natural predators typically keep populations in check.
Acorn Weevil
Acorn Weevil

Acorn weevil (Curculio spp.)

  • Acorn weevils attack both red and white oaks and may destroy large portions of acorn crops each year. 
  • Weevils are brown with a long slender beak. Larvae are white and C-shaped. There can be one or more holes on an acorn. 
  • Natural controls help minimize losses in most years.

 

  

 Ashes -

White ash and green ash (Fraxinus Americana and Fraxinus Pennsylvanica) - Important tree in specialty wood products, such as handles and wood baseball bats. High aesthetic value, wildlife values and environmental values.

Common ash insects:



Insect Description

Emerald Ash Borer

EAB

Emerald ash borer (Agrilus planipennis)

  • Since the early 2000's, the emerald ash borer has killed tens of millions of ash trees in the U.S. The economic and ecological impacts have been significant. 
  • EAB was found in AR in 2014. Learn more about the EAB here.
  • There are many metallic borers that resemble the EAB. However, the EAB is usually larger (half an inch in length), and bright metallic green all over.
  • If you think you encounter an EAB, contact your local county forester (Arkansas Forestry Commission).

 

Hickories, Maples, and Other Hardwoods -

There are many hardwood species in Arkansas' forests. Hickories, maples, dogwoods, elms, and many others increase species diversity in the forestlands across the State. These species contribute to aesthetic, environmental, wildlife, and recreational values, along with some timber value. There are many species that are not specific to one species and will attack trees across species types.

Common multi-species Insects:

 

Insect Description

Forest Tent Caterpillar

Tent Caterpillar

Forest Tent Caterpillar (Malacosoma disstria)

  • May attack oaks, gum, and other hardwoods. Growth loss and dieback can occur, but seldom does mortality. There is also an eastern tent caterpillar (Malacosoma americanum) that feeds on black cherry (Prunus sylvatica) trees and other prunus species. Eastern tent caterpillar primarily impacts the aesthetic value of trees. 
  • Larvae have pale bluish lines along sides of a brownish body, with a row of keyhole-shaped white spots. Adult moths are buff-brown, with darker bands on the wings. Caterpillars often cluster on lower trunks of infested trees.
  • Natural predators  and low and high temperatures usually keep populations in check. Chemical control is an option.

 

Carpenter Worm

Carpenter worm

Carpenter worm (Prionoxystus robinae)

  • Attacks primarily oaks, but also green ash, black locust, elms, maples and cottonwood. Serious impacts on yard trees and degrade of lumber in timber.
  • Larvae are greenish white and are 2 to 3 inches at maturity. Brown pupal skins protruding from entrance holes are common.
  • Maintaining high tree vigor, removing brood trees, and  preventing bark injury are best control methods. Chemical control can be helpful also.

Aphids 

Aphids

Aphids

  • Aphids infest hardwoods and pines in Arkansas. The can be found anywhere on a tree, but prefer new growth. Can cause dieback reduce tree vigor and cause mortality in young trees and seedlings. Aphids can be particularly harmful to yard trees.
  • Aphids vary in body covering and size from one-fiftieth to one-quarter inch long. However, they are all soft-bodied insects. Most aphids are pair-shaped and can vary greatly in color. Often leaves will be curled or folded when being fed on.
  • Natural predators do a good job keeping populations in check. Chemical control is an option for high value trees.

Walkingstick

Walkingstick

Walkingstick (Diapheromera femorata)

  • Attacks oaks and other hardwoods in the South. The only noted severe outbreaks occurred in the Ouachita Mountains, so it can be a problem in Arkansas. Stands may be heavily defoliated and if it occurs over multiple years can result in mortality.
  • Slender and have long thin legs and antennae. When motionless, they closely resemble twigs. two and a half to three inches long. The entire leaf blade except for the stout veins will be consumed.
  • Birds are a natural predator and keep populations in check most years. 

 

Contact Us

Forest Resources
University of Arkansas Division of Agriculture 
Phone: 501-671-2197
Fax: 501-671-2110

Office: 
University of Arkansas Division of Agriculture
Cooperative Extension Service
2301 S. University Avenue 
Little Rock, AR 72204

 

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