Dedicated to Tree Preservation in the Urban Forest

Aphids

 

Host: Various

                                                                                              

Aphids in the landscape can cause a mirid of problems.  Aphids produce a sticky substance called honeydew.  This honeydew can attract other insects that may be harmful to humans such as wasps.  Aphids can also damage tender foliage.  Aphids do have many natural enemies such as lady beetles and lacewings.  Chemical control may be necessary when aphid populations are larger than natural enemies can control. 

 

Leaf Curl Aphid

 

Host: Various

                                                                                              

Leaf Curl Aphids are a common problem for both trees and shrubs.  The aphid feeds on the leaf sucking out nutrients, causing the leaf to “curl” around the insect.  Often large amounts of sticky honeydew is produced.  Leaf curling effects the plants ability to collect sunlight for energy production and robs the plant of valuable nutrients.  Leafs that have been curled by aphids will eventually die and fall off the plant causing stress.  This type of aphid is easily controlled, however, early treatment is recommended before damage occurs.  Treatments can be done by soil injection where by making for a safer and more efficient way to treat this pest.

 

Lilac/Ash Borer

 

Host: lilac, ash, privet

 

Lilac/Ash borer is a particularly damaging insect that can cause stress and crown dieback by girtling the cambian.  Damage can be seen on the trunk of trees as large exit holes.  When adults emerge the pupal skin may be seen on the trunk of the tree.  Reducing plant stress with proper care can help limit attacks.  Chemical control is recommended until bark is heavy enough to resist injury.

 

 

Elm Leaf Beetle

 

Host: Elm

                                                                                              

Elm Leaf Beetle damage can be seen as holes in the leaf.  In heavy infestations, the leaf will brown and dry out.  Some leafs may also fall prematurely as a result of damage.  Chewing of the leaves and defoliation causes Elm trees to look unsightly and will also cause stress.  Elm Leaf beetle is easily controlled.  Depending on the size and location of the Elm, many different controls including soil injections may be used.  Elm leaf beetle does not cause Dutch Elm Disease.

 

 

Ips Beetle

 

Host: Spruce and Pine

 

Ips Beetle is a devastating insect.  Once a Spruce becomes infested, death can occur in a matter of weeks.  Ips Beetle attacks stressed Spruce and begins boring into the trunk.  Adults and larvae create tunnels.  These tunnels interfere with water and nutrient transport up and down the tree.  Newly planted and drought stressed trees are most susceptible.  Spray treatment twice a year is the best defense to help protect trees from infestations.

 

Mountain Pine Beetle

 

Host: Ponderosa Pine, Lodge Pole Pine

                                                                                              

Mountain Pine Beetle can result in the loss of one to a thousand or more trees at a time.  When out break levels are high, this beetle will attack stressed trees and trees that may seem to be healthy.  Mature trees over 8 inches in diameter are most susceptible to attack.  Trees usually dye as a result.  Popcorn shaped pitch masses, reddish boring dust, increased bird activity around trees, and reddish needles are all signs of infestation.  Spray treatments to help protect non infected trees and removal of dead trees is recommended once pine beetle has been detected.

 

Pinyon Tip Moth

 

Host: Pinyon Pine

 

Pinyon Tip Moth damage can be seen on the ends of the twigs and new shoots.  Pitch, a resinous material may be seen at the wound.  Girdling wounds are produced by the larvae feeding on the new growth causing twig dieback.  Pinyon Tip Moth will not cause death, however, continued twig die back will cause stress that may lead to tree failure.  Due to insect susceptibility and life cycle timing, two spray applications may be needed.

 

Poplar Borer

 

Host: Aspen, Cottonwood

 

                                                                                              

Poplar Borer usually attacks mature trees under stress.  The borer tunnels the sapwood pushing out sawdust that can be seen at the exit holes.  Due to the tunneling, girdling (severing the conductive tissue) takes place.  This restricts the flow of nutrients to the leaves and roots.  Proper planting practices are the best way to prevent attack.  Planting trees with sufficient distance allows for best root and canopy growth.  Treatment is usually only recommended once the borer is detected.   Due to the extended life cycle of more than one year, control is difficult.

 

Zimmerman Moth

 

Host: Austrian Pine, can be seen on other pines

 

Zimmerman Moth damage can be seen on the trunk as pitch mass at the wound site where the branch attaches to the trunk.  This may go unnoticed until a snow or wind storm when branches break at the injury site.  Dying or dead branches may be seen in the upper portions of pines.  Damage that has already occurred can not be repaired.  Once infestation is noticed, chemical controls are recommend to prevent further damage.

 

 

 

            

Aphids ● Leaf Curl Aphid ● Lilac/Ash Borer ● Elm Leaf Beetle ● Ips Beetle 

Mountain Pine Beetle ● Pinyon Tip Moth ● Poplar Borer ● Zimmerman Moth