Pest Control

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Our professional applicators can deliver a safe and effective solution to treat and/or prevent many threats to your valued trees, shrubs, and turf. Our approach may include fertilizing and/or organic bioremediation with products from BioFlora®

Call us if you notice symptoms and need on-demand treatment of one tree or you would like a comprehensive preventative program for your entire landscape.

Early spring is a great time to plan for for the growing season and beyond. Click to read a note from Jerry.

Our 2018 Pest Threat Assessment for the Billings area:

Tree and Shrub Pest Threats Billings MT 2018

Pests:

Aphids

 

 

 

 

 

Honeylocust Plant Bug

Apple Scab

 

 

 

 

 

IPS Engraver Beetle and Mountain Beetle (Pine Bark Beetle)

Ash Borers

 

 

 

 

 

Maple Tree Decline

Aspen Leaf and Shoot Blight

 

 

 

 

 

Pine Sawfly

Aspen Leaf Spot

 

 

 

 

 

Scale

Bronze Birch Borer

 

 

 

 

 

Spider Mites

Canker Disease

 

 

 

 

 

Spider Mites of Evergreen

Diplodia Tip Blight of Pine Trees

 

 

 

 

 

Wetwood

Dothistroma Blight of Ponderosa Pine

 

 

 

 

 

White or Wooly Pine Aphid

Dutch Elm Disease

 

 

 

 

 

White Pine Weevil

Elm Leaf Beetle

 

 

 

 

 

 Turf/lawn pests:

Fireblight

 

 

 

 

 

 Turf GrubsNecrotic ring spot


 Aphids 

Aphids are insects that attack a wide variety of trees and shrubs. Aphids are commonly found on Ash, Elm, Walnut, Willow, Cottonwood, Aspen, Apple, Linden, Snowball bushes and many other ornamental trees and shrubs. Aphids first start to appear in spring to early summer, and can reproduce quickly depending on environmental conditions. An aphid population can increase in numbers very quickly.
Symptoms and Life Cycle 
Aphids are tiny, soft-bodied insects that are found clustered together on the leaves of trees and shrubs. The leaves may appear to be curled, thickened or discolored. Damage occurs when the aphid sucks the juices out of the leaves. Since they are unable to fully digest all of the sugars in the plant sap, the insect secretes the excess in a liquid called "honeydew" which often drips onto leaves, branches, trunks, cars, sidewalks, patios, etc. A sooty mold may develop on the honeydew causing those surfaces to appear dirty. Ants feed on the honeydew and are often present in the areas that aphids are found.

Some Aphids spend their entire life on one plant while other go from plant to plant. Aphids that hatch from over-wintering eggs are wingless females that give birth to live aphids and can produce many generations throughout the summer. Some aphids are born with wings so that they can travel to less populated hosts. In the fall, the female aphid lays eggs in the bark for over-wintering.
Control
Aphids should be sprayed at the first sign of an infestation. This should be done with an insecticide such as Astro, Talstar, or Orthene. A certified arborist can also systemically inject a tree to control the present generation of aphids or to provide season long control, which should be done in the spring of the year.

Repeat applications may be necessary as reinfestation can occur. A follow-up application may be necessary as early as 21 days, as spraying only control aphids present at the time of application.
 

Apple Scab 

SYMPTOMS AND SIGNS

Apple Scab is a disease that is found on both apple and crab apple trees. Symptoms of Apple Scab include dead spots on the leaf usually found along the leaf mid rib or along the veins. The spots start out as an olive green color and continue to darken and enlarge throughout the growing season. Depending on the conditions when the fungus forms, the spots may even have a velvety appearance. As the disease continues, the leaf may appear to be chlorotic due to lack of food production or the leaf may even dry up and drop off. The fungus may also infect parts of the flower and the fruit as well as the leaf tissue.

LIFE CYCLE

The Apple Scab fungus over-winters in fallen leaf debris. In the spring when the over wintering spores release they become airborne and spread by the wind. A thin film of moisture attaches the spores that land on the newly emerging leaf. Fungus spores that are attached to the leaf need periods of high humidity in order to continue to grow. Prolonged periods of leaf surface wetness, along with high relative humidity favor the development of Apple Scab.

CONTROL

Apple Scab is most effectively controlled in the spring of the year as the new leaves are beginning to form. Repeat applications with a fungicide containing Captan, Eagle, and Banner Max, and labeled for application on apple trees is most effective. These applications are needed in order to reduce the number of scab lesions. Preventative applications are necessary if the conditions favoring Apple Scab development are present in the spring. If there are relatively dry conditions in the spring, there may be little or no Apple Scab present.

 
 

Ash Borers

In Montana the Ash Borers attack green or white Ash trees, European Mountain Ash and Lilacs. The larvae bore into the wood of the host plant, creating holes in the trunk and main crotch area leading to swelling and cracking of the bark. Die back of specific branches is then observed mid summer or the following spring after the attack. A borer hole made by the larvae creates an entry for secondary infections by insects and disease organisms. Death to the host plant can occur if attacks go unchecked in continuous years.

Ash trees that are grown in a street or landscaped environment are highly susceptible to borer attack. Trees in unthrifty conditions from low fertility, drought, or defoliated by leaf-eating caterpillars are especially vulnerable.

The Emerald Ash Borer (EAB) has not yet been found in Montana but we will only know its presence by irreversible damage and tree loss. Our preventative measures will help keep your valued shade tree(s). Read More

LIFE CYCLE

The insect over-winters as nearly mature larvae in the trunk of the host plant. In the spring the adults (wasp-like moths) emerge, mate, and begin laying eggs on the host trees. The eggs hatch in approximately ten days and the larvae tunnel into the host plant. There is only one generation per year.

PREVENTION

A spray application of Acme Borer spray or Astro can be applied to the trunk of the tree three times at two-week intervals, beginning approximately June 15th. The tree can also be injected with Bidrin or Dendrex by a certified arborist once a year around mid June through the end of June. Keping the tree free of destructive insects and utilizing a good fertility program will keep the tree healthy.

CURATIVE

If the tree has been attacked, it should be injected by a certified arborist. If the tree is in an unthrifty condition, a multi nutrient should also be injected into the tree to give it a boost. In late fall or early spring the tree should be deep root fed, with the above prevention measures taken the following spring.

 
 

Aspen Leaf and Shoot Blight

Foliage diseases can reduce the aesthetic value of aspen and cottonwood. Occasionally, a severe disease outbreak causes premature defoliation or dieback of parts of the tree.
If a tree loses its leaves early in the season, it may grow new ones and its health is not seriously affected. If it loses them in midsummer, however, growing new leaves may prevent the tree from fully hardening off before cold weather or reduce the amount of stored food. This leads to increased danger of frost damage, reduced growth, and predisposition to other diseases or Insects. If it loses its leaves late in the season, it will not grow new ones or it may lose much vigor.

Leaf and Shoot Blight

Leaf and shoot blight, caused by the fungus Venturia, is a disease affecting young aspen and cottonwood tissue primarily in the mountains.
In the spring, symptoms first become visible on leaves near shoots infected the previous season. Brown to blackened, irregularly shaped areas spread through the leaves, causing them to dry and become distorted. Typically, the fungus spreads down through the succulent new shoot, causing cankers that blacken and curl the stem tip until it resembles a shepherd's crook (see picture). Death of new shoots causes distorted, shrubby growth.
The leaf and shoot blight fungus survives the winter mainly on shoots infected the previous season. Spores are windblown early in the season and infect newly expanding leaves and shoots. As the season progresses, uninfected tissue becomes more resistant to the disease.

Disease Management

Tree resistance is the best way to prevent foliar diseases. Several poplar hybrids or species are resistant to one or more of these diseases. Ask your local nursery for a resistant variety. Some aspens are resistant to leaf spots, but aspen production methods make it difficult to select trees for resistance.
Sanitation is an effective control for some foliar diseases. Fall removal of infect infected leave, twigs and branches can reduce the amount of disease the next spring. Raking and destroying infected leaves can reduce Marssonina leaf spot, ink spot and leaf rust. The shoot blight fungus overwinters in diseased stems and twigs, so it can be pruned out to reduce new infections.

Keep leaves as dry as possible to reduce the incidence of leaf spots.

Fungicide, if applied early enough, can prevent foliage diseases. Injectable fungicides provide consistent control and will move through the entire tree canopy when properly applied.

 
 

Aspen Leaf Spot

Foliage diseases can reduce the aesthetic value of aspen and cottonwood. Occasionally, a severe disease outbreak causes premature defoliation or dieback of parts of the tree.
If a tree loses its leaves early in the season, it may grow new ones and its health is not seriously affected. If it loses them in midsummer, however, growing new leaves may prevent the tree from fully hardening off before cold weather or reduce the amount of stored food. This leads to increased danger of frost damage, reduced growth, and predisposition to other diseases or Insects. If it loses its leaves late in the season, it will not grow new ones or it may lose much vigor.
The fungus Marssonina causes the most common foliage disease on aspen and cottonwoods in urban and forested areas of Montana.
Marssonina leaf spots are dark brown flecks, often with yellow halos (Figure 1). Immature spots characteristically have a white center. On severely infected leaves, in wet weather, several spots may fuse to form large black dead patches (Figure 2). Spots also may develop on leaf petioles and succulent new shoots.
Marssonina survives the winter on fallen leaves that were infected the previous year. With spring and warmer, wet weather, the fungus produces microscopic "seeds" or spores that are carried by the wind and infect emerging leaves. Early infections are rarely serious, but if the weather remains favorable, spores from these infections can cause a widespread secondary infection. Heavy secondary infections become visible later in the growing season and cause premature leaf loss on infected trees.

Disease Management

Tree resistance is the best way to prevent foliar diseases. Several poplar hybrids or species are resistant to one or more of these diseases. Ask your local nursery for a resistant variety. Some aspens are resistant to leaf spots, but aspen production methods make it difficult to select trees for resistance.
Sanitation is an effective control for some foliar diseases. Fall removal of infect infected leave, twigs and branches can reduce the amount of disease the next spring. Raking and destroying infected leaves can reduce Marssonina leaf spot, ink spot and leaf rust. The shoot blight fungus overwinters in diseased stems and twigs, so it can be pruned out to reduce new infections.


Keep leaves as dry as possible to reduce the incidence of leaf spots.


Fungicide, if applied early enough, can prevent foliage diseases. Injectable fungicides provide consistent control and will move through the entire tree canopy when properly applied.

 
 

Bronze Birch Borer

The Bronze Birch Bore has already killed many Birch trees in Billings. If Birch trees are not attended to properly and in a timely fashion, the Bronze Birch Bore will eventually kill all the Birch trees in a landscape environment.

PREVENTION

Birch trees need to be fertilized each year in the fall or early spring to maintain a healthy tree, which is less likely to be attacked. A slow release fertilizer with micronutrients placed in the root zone will be most effective.
To protect the Birch tree during the time of attack by the Bronze Birch Bores, the trunk and main branches need to be treated with Acme Borer Spray or Astro as per label directions. Treatments in Billings should be made approximately the first of May.
Protect your Birch tree from mowing and weed trimmer damage by mulching around the tree. A Birch tree must remain healthy to survive and resist a Bronze Birch Bore attack.

IF TREE IS ATTACKED

Should your Birch tree show symptoms of Bronze Birch Bore attack, the following procedures need to be done to save your tree.

The dead or flagging portions of the tree need to be trimmed and removed from the property and destroyed.
The tree needs to be injected with Bidrin or Dendrex by a certified applicator. This will kill the larvae under the bark of the tree.
Fertilize the tree at the time of Bidrin or Dendrex injection, if done before mid July, and follow up with a deep root feeding in fall or early spring.
Refer to the annual maintenance procedures to protect the tree from reinfestation the following year.

One thing is certain, if your Birch trees are NOT properly maintained, they are very susceptible to Bronze Birch Bore attack.

 

Canker Disease

Cankers are a fungus disease caused by a number of different pathogens and attack many varieties of trees; the following are general diagnosis and treatment practices.

SYMPTOMS

The disease is not usually conspicuous at first but once it gets started it first kills scattered twigs and then proceeds rapidly. Cankers form in all sizes and ages of stems. Cankers range in size from small brown spots to large lesions that involve both bark and cambium. Many cankers girdle twigs and branches causing die back. The fungus may then move down into larger stems and cause perennial cankers possible girdling the tree trunk causing premature yellowing of leaves, premature leaf drop and possible death.

Canker diseases are most often spread in the spring and are most apt to attack those trees and ornamentals growing in infertile soil, weakened by insects and drought, or wounded plants (hail, construction, etc.). Canker diseases are most abundant in landscaped environments.

TREATMENTS

In Billings Canker diseases are the number one cause of death to trees and ornamentals. Canker diseases can attack most varieties of trees but are most prevalent in Poplar, Willow, Spruce, Cottonwood, Aspen, Maple, Locust, Elm, and Russian Olive.

When Cankers are diagnosed in a tree, the tree should be microinjected with a fungicide. If the tree appears to be in an unthrifty condition it would be recommended to microinject a combination of a fungicide and a fertilizer to give the tree a quick boost.

To build vigor in the tree a deep root feeding in the fall or very early spring is recommended. The two following springs a microinjection of a fungicide is recommended to suppress the canker disease and allow the plant to overcome the symptoms.

A three-year program of proper fertilization, watering, and pest control will help the tree repair and maintain its vigor. Should the tree not show a positive response or stabilize after the first or second fungicide injection, it is an indication the disease has progressed too far to be controlled. It would be a waste of resources to microinject the tree only once (even if the response is good) and not follow up with the two consecutive spring treatments.

 
 

Diplodia Tip Blight of Pine Trees

Diplodia Tip Blight is a fungus disease that occurs in native and imported pine species. The damage is most evident in pines found in landscapes and windbreaks.

SIGNS AND SYMPTONS

The most visible sign of Diplodia Blight is brown, stunted new shoots with short brown needles. New shoots throughout the entire crown may be infected. Although the damage is usually most visible first in the lower crown, infection varies among major branches. Repeated infections reduce growth, deform trees and ultimately decline the overall health of the tree.

Diplodia Tip Blight is most often observed in pine trees that have had their environment altered by construction, change of drainage, soil ph altered, compaction, grass planted over root zone, etc. Unthrifty trees may not show symptoms of stress for a number of years after they have had their environment altered.

TREATMENT

Trees diagnosed with Diplodia Tip Blight should be microinjected with a fungicide by an arborist. Should a spray program be selected, use Cleary’s 3336, two applications during the candling period. If the tree appears to be in an unthrifty condition, it would be recommended to microinject the tree with fungisol and fertilizer to give the tree a boost.

Removal of the infected branches may be justified on the basis of improving the appearance, but pruning should not take place during the times of the year that are most favorable for the spread of the injection through the wounds.

 
 

Dothistroma Blight of Ponderosa Pine

Dothistroma Blight is a devastating foliage disease that attacks Ponderosa and Austrian Pine trees in the Billings area.

SYMPTOMS

Dothistroma Blight symptoms are first observed in a color decline of the pine trees. Close observation of the needles indicates tan, brown, or reddish spots. Greenish bands are present on the needle, then turn to reddish colored bands as the disease progresses. The needle progressively turns light green, tan, and then brown with the base of the needle remaining green. Infected needles drop prematurely. Newly emerged needles are infected any time it rains from June to October.

Dothistroma is most often observed in native stands of pines that have had their environment altered by construction, change of drainage, soil ph altered, compaction, grass planted over root zone, etc. Unthrifty Ponderosa trees may not show stress from construction or landscaping for a number of years after they have had their environment altered.

TREATMENT

Ponderosa Pines that have been diagnosed with Dothistroma should be systemically injected with a fungicide in early June to protect the new growth that is emerging from the candle. Should a spray program be selected, apply Daconil 2787 every two weeks through the candling period (early June, Mid June, early July).

To enhance vigor of the diseased tree, fertilization is recommended at the time of the systemic injection or root fertilization in the fall or very early spring.

If the diseased tree stabilizes or shows improvement, the preceding recommendation should be repeated for two to three years or longer to insure recovery of the tree.

 

Dutch Elm Disease

Dutch Elm Disease is a systemic vascular wilt disease caused by a fungus. Dutch Elm Disease predominately attacks the American Elm in the upper great plains.

SYMPTOMS

The earliest symptoms are yellowing or wilting of the leaves on single branches in the upper crown. The yellow or wilted leaves quickly turn brown and die. This condition spreads rapidly, one branch at a time, to progressively larger branches and soon is distributed throughout the crown. Symptoms appearing in late spring usually mean the tree will be dead by the end of the summer, larger trees, however, may take several years to die. Symptoms beginning in mid summer usually mean the disease will only progress to a few branches. The next year, however, the disease will progress no further during that season, and the tree often remains free of the symptoms the next season. Infected branches contain brown discoloration in the outer xylem.

DISEASE CYCLE

The Elm Bark Beetle carries the fungus from infected wood to healthy trees. These insects lay their eggs in dead or dying elms. In late fall the eggs hatch and produce larvae, which tunnel under the bark. In early spring, they emerge as adults. The fungus produces sticky spots in the larval galleries. These spores are picked up on the body of the beetle as it emerges from the tree. The beetle carries the spores to healthy trees as it feeds. Infection also occurs through root grafting.

PREVENTION

The preferred method is to prevent infection of a healthy tree. This is done with an annual application of Alamo by a trained arborist. A prevention application of Alamo can be done any time during the growing season but preferably in the spring when leaves are developing on the tree. To maintain a healthy tree, a fertilization program is recommended with proper pest control.

CONTROL

Control of Dutch Elm Disease can only be done in the early stages of the disease. If a diagnosis is made with 25% or less infestation of the tree (preferable 10% or less), the following control measures must be taken. An application of Alamo at the therapeutic rate should be done as soon as possible. The infected part of the Elm needs to be removed and taken from the premises. An annual application of Alamo at the preventative rate needs to be done- preferably early spring.

 

Elm Leaf Beetle

Elm Leaf Beetles feed on Siberian or Chinese Elms. The adults lay yellow egg masses on the bottom of the leaves. The first generation emerges approximately the first to MID PART OF JUNE. The eggs hatch and the larvae feed on the leaves, leaving a brown area between the leaf and veins. The second generation hatches about late July or early August. The damage done to the trees by the feeding of the larvae will not kill a tree by itself but will cause the tree to go into a state of decline allowing other diseases such as canker, wet wood, and Verticilium Wilt to kill the tree.

Controlling Elm Leaf Beetle larvae is done by spraying the tree to control the first generation and again during the second generation. If spraying is not possible, injection can be done during the first generation and will control both generations.

In the fall the adult beetles invade the home to spend the winter hibernating in the attic, walls, insulation etc.

In late winter and spring they often roam the house with no special purpose. Many times the homeowner will have severe infestations. To control the winter infestation inside the home, the following must be done:

  • Control the Elm Leaf Beetle in the larvae stage on the trees with spraying or injection. 
  • An outside perimeter spraying in October to kill many of the invading pests before they enter the home.
  • Place pest strips in the attic in late September.
  • Should the population be severe inside the home late winter or spring, use timed-release dispenser to control roaming adult beetles.

Elm Leaf Beetles need to be controlled or repeated infestation will cause the tree to decline in health and allow large populations of the beetle to be available in the fall to invade the home. Fertilizer injection or liquid soil fertilization will enhance the vigor of trees that have had infestation.

 
 

Fireblight

  
Fireblight is a bacterial disease spread from tree to tree during blossom by pollinating insects, birds, and raindrops. Fireblight infects apple trees, ornamental crabapple trees, pear trees, Mountain Ash, Cotoneaster, and other various ornamental trees.
Symptoms
Symptoms of Fireblight are die-back of infected branches from the outer tip inward. The leaves appear to have wilted and dried on the branch and remain attached (leaves and fruit appear to be scorched by fire for Fireblight). The twigs and branches will be discolored, blackened, and dying. Symptoms start to appear shortly after petal fall and continue until mid summer. Fireblight bacteria will over winter in infected twigs and branches.
Curative
After diagnosing Fireblight, the infected twigs and branches must be pruned out of the tree. Infected branches need to be pruned approximately six inches into the uninfected part of the branch. Pruning tools must be disinfected between each cut (a 2% Clorox solution or other quality disinfectant will work). Pruning is the only solution for trees bearing edible fruit. Ornamental trees should be pruned after diagnosed with Fireblight in the summer and injected with Oxytetracycline in the fall or early spring by a professional arborist. A quality fertilization program is recommended for ornamental trees in late fall or early spring to increase the health and vigor of the tree.
Prevention
On edible fruit trees two to four sprays with streptomycin done every five to seven days during pre-blossom and blossom is required to prevent infection of the tree. Timing of application is most critical.

Ornamental trees require a preventative injection early spring before or at pre-blossom. A fall injection with Oxytetracyline works very well for prevention of Flireblight the following spring.

Always select Fireblight resistant varieties when purchasing plant species that can be infected with Fireblight.
 

Honey Locust Plant Bug

As its name suggests, the honey locust plant bug attacks the Honey Locust tree. The adult bug is light green to yellow and has a four segmented antennae and a beak-like mouthpart. Eggs are laid under the bark and hatch when the buds of the leaves begin to open. The nymphs then crawl onto the leaves of the tree to feed. If the infestation is extensive, complete defoliation can occur.

Some years the threshold of insect attack is small and the tree survives the infestation without harm. For the years when the infestation is heavy, damage can result quickly causing the tree to lose vigor and become weak which then results in winter injury. Timely applications are necessary for this pest.

Chemical application control includes spraying at the time of infestation, chemical trunk injection at the time of infestation or using a chemical soil drench application prior to infestation. The soil drench application technique of control is easily done in the fall with control lasting through the next growing season.
 
 

Pine Bark Beetle and IPS Engraver Beetle

  
Pine Bark Beetle and IPS Engraver Beetle attack and kill pine trees and other species of long needle evergreens that have been planted or are naturally grown in a landscape setting around homes.

The IPS Beetle attacks long needle pine trees of various sizes in the spring and has multiple flights through the season. The Mountain Pine Beetle attacks all species of pine trees in the latter part of July and August. Both species of beetles are devastating to a tree that is not in the healthiest of condition.

The most susceptible trees are the ones that have had alterations made to their environment by construction within the last ten years; for example root damage, fill added over root systems, natural water drainage rerouted and grass planted and maintained underneath the trees. Trees affected with construction alterations are generally the most aesthetically valuable trees to landscape settings. Drought, fire damage, and over-population also weaken valuable trees.

To maintain valuable pine and spruce trees the following steps should be taken:
  • Identify which trees have great aesthetic value to your property.
  • The valuable trees should be deeply watered twice a month during the growing season. Lawn watering will not suffice.
  • Your transplanted or small natural trees should be deep root fertilized in the fall or early spring until they reach maturity. Fertilize mature trees every two to three years to maintain a healthy tree. Lawn fertilizing is not adequate.
  • Valuable trees should be sprayed every year with Onyx or Astro per label directions. These spray residuals are restricted for use by professional licensed applicators and will protect the trees through the entire growing season. Spraying for prevention of Bark beetle or IPS Beetle is imperative after any type of damage is done to a healthy tree, for example construction, car hitting tree, drought, etc. Systemic injection of fertilizer will increase the vigor of unthrifty or construction damaged trees.
If your trees have had a beetle attack:
  • When beetle damage is diagnosed during the summer or fall, the tree should be injected by a certified applicator with Metasystox R to kill the larva underneath the bark.
  • The tree should be deeply watered (unless too much moisture due to poor drainage has weakened the tree) and deep root fertilized in the fall or early spring.
  • The tree needs to have a preventative spray applied the next spring, plus the preceding standard prevention measures taken.
It will take 50 to 100 years to replace a mature Ponderosa Pine tree in your landscape.
 
 

Maple Tree Decline 

Mature silver maple trees in the Billings area suffer from a composite group of problems contributing to a syndrome of maple tree decline. Problems stem from soils that are alkaline, and also root diseases causing insufficient mining of soil nutrients.

Symptoms of Maple Tree Decline

Early symptoms are cloratic appearance of leaves (yellowing)
As the tree matures over a number of years, the clorosis increases, brown spotting takes place on the leaves, scorching and premature leaf drop occurs
Threes in the later stages show twig and branch die back
The above symptoms can occur over a twenty to thirty year time frame. Eventually the tree will show enough die back it will no longer enhance the landscaping and would need to be removed.

Treatment for Maple Tree Decline

For a number of years therapeutic treatment only improved the health of the tree to a limited extent. Now Jerry Anderberg & Associates can treat your maple tree to reverse the decline.

  • Treatment is recommended in the fall with September or October being the most desirable months.
  • Treatment will enhance color, making it green
  • Treatment helps relieve summer scorch and other stresses
  • Treatment prevents additional die back (it will not revive branches that have previously died back- those should be removed by a skilled arborist)
  • Treatment will need to be repeated at one to two year intervals

Mature silver maple trees quite often are the most valuable plant in the landscaped environment providing shade and enhancing the appearance of the property.

 
 

Pine Sawfly

The pine sawfly attacks the long needle ponderosa pine trees. The larvae feed off the one and two year old growth. If allowed to complete their life cycle on the tree, the sawfly will consume the esthetic value of the tree. The stress caused by the defoliation of the tree may lead to other problems such as pine bark beetle.

Life Cycle

The pine sawfly over-winters as eggs on the needles. The eggs hatch late spring to early summer. The larvae feed on the first and second year needles. There is generally one life cycle per year.

Curative

The trees should be sprayed when the larvae is first noticed. We recommend spraying with products such as Astro or Sevin. If the tree is of high aesthetic value and is in a un-thrifty condition, a multi-nutrient should be injected into the tree or root fertilization in the fall of the year to help regain its vitality.

 
 

Hard-Bodied Scale

Hard-bodied scale is also called Oyster Shell scale due to the resemblance it has to an oyster in the adult phase of its life. Scale attacks many woody plants such as maple, ash, aspen, lilac, dogwood and others. This pest causes damage to the tree by attaching itself to the bark and sucking the sap out of the tree. If infestation becomes severe damage or death to the tree can occur.

This scale produces one generation per year and overwinters in the egg stage. It then hatches in the spring and quickly attaches itself to the plant to feed. The mother scale is about 1/8-inch long, brown or gray, slightly banded, and the general shape of an oyster shell. The overall appearance of the scale often is similar to that of the underlying bark and these insects are easily overlooked.

Oyster shell scale can be hard to control because of the thick shell they build around themselves. However, this scale can be treated with a spring trunk surface application of a restricted use ornamental chemical called Safari. Scale can also be treated by the application of a highly refined horticulture oil applied to the crawling stage of the scale life cycle. This control needs specific timing of the application to the crawling life cycle. Repeat applications may be needed to control late outbreaks of the crawling stage.
 
 

Spider Mites

Spider mites are common pest problems on many plants around yards and gardens in Billings. Injury is caused as they feed, bruising the cells with their small, whip-like mouthparts and ingesting the sap. Damaged areas typically appear marked with many small, light flecks, giving the plant a somewhat speckled appearance.

Following severe infestations, leaves become discolored, producing an unthrifty gray or bronze look to the plant. Leaves and needles may ultimately become scorched and drop prematurely. Spider mites frequently kill plants or cause serious stress to them.

Many spider mites produce webbing, particularly when they occur in high populations. This webbing gives the mites and their eggs some protection from natural enemies and environmental fluctuations. Webbing produced by spiders, as well as fluff produced by cottonwoods, often is confused with the webbing of spider mites.

Honey Locust, particularly those in drier sites, are almost invariably infested with the honey locust spider mite (Platytetranychus multidigituli). Other mites may affect shade trees such as elm, mountain ash and oak.

Most spider mite activity peaks during the warmer months. They can develop rapidly during this time, becoming full-grown in as little as a week after eggs hatch. After mating, mature females may produce a dozen eggs daily for a couple of weeks. The fast rate of development and high egg production can lead to extremely rapid increases in mite populations.

Dry conditions greatly favor all spider mites, an important reason why they are so prevalent in the more arid areas of the country. They feed more under dry conditions, as the lower humidity allows them to evaporate excess water as they excrete. At the same time, most of their natural enemies require more humid conditions and are stressed by arid conditions. Furthermore, plants stressed by drought can produce changes in their chemistry that make them more nutritious to spider mites.

Water Management: Adequate watering of plants during dry conditions can limit the importance of drought stress on spider mite outbreaks. Periodic hosing of plants with a forceful jet of water can physically remove and kill many mites, as well as remove the dust that collects on foliage and interferes with mite predators.

Chemical Controls: Chemical control of spider mites generally involves pesticides that are specifically developed for spider mite control (miticides or acaricides). Few insecticides are effective for spider mites and many even aggravate problems. Furthermore, strains of spider mites resistant to pesticides frequently develop, making control difficult. Because most miticides do not affect eggs, a repeat application at an approximately 10 to 14 day interval is usually needed for control.
 
 

Spider Mites of Evergreen 

The Spruce Spider Mite is one of the most damaging pests of spruces and many other conifers. These mites suck sap from the undersides of the needles. As a result of feeding, the green pigment disappears, causing the striped appearance. Spider mites first appear between April and June. A complete generation may be produced in only seventeen days so mites can rapidly build up to tremendous numbers during the growing season. Young spruce trees may die the first season. If left uncontrolled for several years, older trees may die with symptoms progressing from the lower branches upward.

SYMPTOMS

Needles are striped yellow and dirty with symptoms progressing from the lower branches upward. There may be silken webbing on the twigs and needles. Needles usually turn brown and fall off. To determine if the tree is infested with mites, hold a sheet of white paper underneath some striped needles and tap the foliage sharply. Minute dark green to black specs about the size of pepper grains will drop to the paper and begin to crawl around.

TREATMENTS

For controlling spider mites an application of Avid, Floramite, Onyx, Dimethoate or Isotox should be applied at seven to ten day intervals.
Certified arborists should use Avid or Vendex and repeat applications as needed or at 30-day intervals. Constant monitoring with the above method should be done to detect if repeat sprayings are necessary.
Injection by a certified arborist can be done on trees where spraying is not practical or the saving of beneficial insects is desired.

Fertilizer injections or liquid injection of fertilizer will increase the vigor of trees that have been attacked. A properly fertilized tree will be more tolerant of spider mite attacks.

Spider mites can be active until late in the fall or even during warm periods in the winter.

 
 

Wetwood

Wetwood is a bacterial infection that is common in trees such as Elms, Willow, Cottonwoods, Maple and Aspen. These species of trees growing on sites with wet and/or poorly drained soils are more likely to obtain wetwood.

SYMPTOMS AND SIGNS

Wetwood, a water-soaked, sap-oozing, condition of wood can be found in wounds, cracks, branch crotches, and mainly during the growing season. The infected area of the tree is usually discolored, gives off a rancid or sour odor, and there is usually a secretion or slime fluxing from the affected areas. Foliage of the affected limbs is often prematurely yellow, scorched, and wilted. Wilting may cause die back of various branches and may affect the entire crown area if left untreated over several years. Wounds infected with wetwood do not heal; therefore, lengthening susceptibility to decay fungi. Wetwood may contribute to the general decline of the tree, especially of old trees and trees of low vigor.

Bacteria that affect the heartwood cause Wetwood. This infection causes abnormally high sap pressure. This pressure is produced by a bacterial fermentation and forces the fermented sap out cracks or other wounds. The wetwood is especially evident when the tree is growing rapidly. The problem may continue for many years.

CONTROL

Wetwood can be controlled by an injection of Oxytetracycline by a certified arborist. The injection should be followed up by fertilization to aid in the recovery of the tree. Wetwood should be treated, as the condition of the tree requires.

Should the tree show a positive response or stabilization after the first or second antibiotic application, the tree should be put on an annual fertilization program to encourage overall tree health.

 

 

White or Woolly Pine Aphid

The White or Woolly Pine Aphid attacks native Ponderosa pines and other species of long needle pine and spruce in the fall or early spring, causing severe damage to the trees. The needles first turn lime-green in color then turn brown. This aphid will continue to be active, feed, and reproduce until continual low temperatures reduce their activity. This usually does not take place until the latter part of November to mid December.

The aphids over-winter in the egg stage. The eggs can be distinguished as dark specs laid in a perfect line on the pine needles.

In the spring the eggs hatch and the aphids feed, reproduce, and spread until hot weather sets in and then their activity comes to a standstill.

Many homeowners observe the change in color to the pine in the fall but associate it with winter setting in.

We recommend spraying these trees at the first indication of the Woolly Pine Needle Aphid being a problem. This should be done with aphidicides like Talstar, Astro, etc.

The tree can also be injected by a professional applicator with aphidicide injections of Metasystox R. This will kill sucking-active aphids and give approximately four weeks residual. Injecting the aphidicides into the trees offers an advantage, as it does not harm predatory insects.

Another application may be needed in the spring after the aphids have hatched and are active.

If the environmental factors are favorable, aphid population can build up very rapidly.

 
 

White Pine Weevil

White Pineweevil, Pissodes strobe (Peck), is a serious destructive insect pest of spruce trees in Montana with either forked or deformed trees resulting from repeated infestations. Spruce trees of any heights are susceptible to attack.

The adult white pine weevil is a long reddish-brown weevil with white patches on its wing covers. Like most weevils, the adult has a long snout-like beak from which knobbed antennae arise. The larvae, which live beneath the bark, are white, legless, with a distinct brown head and 5/16" long when mature.

The adults over-winter in the duff under trees. In Mid-March to mid-April adult females climb trees to feed on leaders. Females lay one to five eggs in the feeding wounds in tree leaders. The eggs hatch in about a week and the larvae feed just below the bark tunneling downward, girdling and killing the shoot as they go.

Symptoms: The first symptom evident from attack by the white pine weevil is glistening droplets of resin on terminal leaders in late March and April. This is the result of punctures made by adults in the process of feeding and cutting egg-laying sites. The larvae do the most damage as they tunnel downward in the leader, causing the shoot to wilt and eventually die. Repeated infestations in successive years result in a deformed or forked tree.

Biological Control: Natural enemies do not provide adequate control.

Mechanical Control: Prune infested leaders. As soon as the leader droops, prune the leader out just below where the bark discoloration stops. Remove the pruned leader containing the larva from the site. Corrective pruning of the injured top involved removing all but a single shoot (one of the largest) at the topmost healthy whorl. This promotes healing, resumption of vertical growth and straightening of stem form.

Chemical Control: Spray only the leader with a registered insecticide in the spring before the adult feeding is observed (late-March through April).
 

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Turf Grubs

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Necrotic Ring Spot

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