Pesticide Review Pt. 5 - Forest Pest Control ‐ Insects

Text provided questions are in Pt. 1

What do Bark beetles use trees for?

Breeding Sites

What are two natural important role that Bark beetles play?

killing weak or old trees or aiding the decomposition of dead wood.

What attracts bark beetles to damaged trees?

An odor emitted from stressed or injured trees (where attacks usually first occur)

How do beetles that develop inside trees spread to other trees?

A) They fly through large cracks in the bark
B) They emerge through small round holes in the trunk and move to other trees
C) They tunnel underground to nearby trees
D) They are carried by wind over long distances

They emerge through small round holes in the trunk and move to other trees

What do adult beetles do when they enter trees?

A) They immediately leave without causing damage
B) They lay eggs, often creating distinctive tunnels or brood chambers
C) They feed only on the leaves of the tree
D) They build nests on the surface of the bark

They lay eggs, often creating distinctive tunnels or brood chambers

What do the grub-like larvae feed on after borering into the wood?

tree tissue or fungi brought to the tree by colonizing individuals

What type of trees do most bark beetle species in Kentucky attack?

A) Healthy, vigorously growing trees
B) Trees that have been significantly weakened by disease, smog, competition, or physical damage
C) Only newly planted saplings
D) Trees with thick bark that are resistant to insects

Trees that have been significantly weakened by disease, smog, competition, or physical damage

Extensive tunneling by the larvae can

girdle and weaken or eventually kill the tree

How do healthy trees defend themselves against attacking insects?

A) By growing thicker bark to block insects
B) By producing defensive compounds that can kill, injure, or immobilize insects with sticky fluid
C) By dropping all their leaves to prevent insect feeding
D) By attracting predatory birds to eat the insects

By producing defensive compounds that can kill, injure, or immobilize insects with sticky fluid

Despite healthy trees having some form of protection under outbreak conditions, large numbers of beetles can

successfully attack healthy trees with disastrous results for the lumber industry

What unique feature is associated with some bark beetles, such as ambrosia beetles?

A) They feed only on tree sap
B) They carry a fungus that grows within their galleries
C) They avoid trees with fungal infections
D) They eat the outer bark of healthy trees

They carry a fungus that grows within their galleries

What do ambrosia beetle larvae feed on inside the tree?

A) Tree sap
B) Wood fibers
C) The fungal growth introduced by the beetles
D) Other insects within the tree

The fungal growth introduced by the beetles

What can happen when the fungus introduced by some bark beetles spreads systemically in a tree?

A) The tree becomes immune to other pests
B) It increases the tree’s growth rate
C) It causes disease of the vascular system
D) It strengthens the tree’s structural wood

It causes disease of the vascular system

How do good silvicultural practices reduce the potential for bark beetle attacks?

reducing stress and keeping trees actively growing.

Why is prompt removal of damaged trees important in managing bark beetle populations?

A) It improves soil fertility
B) It prevents trees from regrowing too quickly
C) It significantly reduces the likelihood of successful bark beetle attacks
D) It allows beneficial insects to nest in the area

It significantly reduces the likelihood of successful bark beetle attacks

Why can insecticides not save trees that have already been successfully attacked by bark beetles?

A) The insecticides are too toxic for use on mature trees
B) Bark beetles become resistant immediately after attacking
C) Insecticides do not penetrate the tree to kill developing larvae
D) Bark beetles abandon trees once insecticide is applied

Insecticides do not penetrate the tree to kill developing larvae

In which situation is insecticide application effective for bark beetle control?

A) After larvae have fully developed inside the tree
B) On trees that have already died from infestation
C) As a preventative measure on uninfested, high-value trees at risk
D) Only during the winter months

As a preventative measure on uninfested, high-value trees at risk

What determines the area of a tree that needs to be treated with insecticide?

A) The age of the tree
B) The time of year
C) The insect species being targeted
D) The color of the tree bark

The insect species being targeted

How should the insecticide spray mixture be applied to the tree for effective treatment?

A) Lightly mist only the top branches
B) Apply only to the trunk base
C) Thoroughly wet the appropriate area of the tree with the spray mixture
D) Spray only the surrounding soil

Thoroughly wet the appropriate area of the tree with the spray mixture

What parts of living trees do roundheaded and flatheaded wood borers typically infest?

A) Only the bark surface

B) Terminals, shoots, twigs, and roots

C) Only the leaves and flowers

D) The fruit and seeds

Terminals, shoots, twigs, and roots

Why are terminal and shoot insects particularly important in forestry and tree management?

A) They only affect mature trees ready for harvest
B) They improve the growth rate of young trees
C) They are especially damaging during forest regeneration, early stand growth, and in nurseries or ornamental trees
D) They help protect young trees from disease

They are especially damaging during forest regeneration, early stand growth, and in nurseries or ornamental trees

What is a significant consequence of Roundheaded and flat headed wood borers?

A) They improve soil nutrients for nearby plants
B) They reduce competition among tree species
C) They damage or destroy trees that would otherwise produce quality lumber or wood products
D) They assist in the pollination of forest plants

They damage or destroy trees that would otherwise produce quality lumber or wood products

Most borers are secondary invaders that attack

bark and wood of trees that are seriously weakened, dying, or recently cut.

Provide some examples of secondary invaders (wood borers).

carpenterworms, oak clearwing borers, metallic wood borers, and pine sawyers.

Why are control measures often difficult and not economically feasible for trees attacked by carpenterworms, oak clearwing borers, metallic wood borers, and pine sawyers?

A) Because these insects are resistant to all insecticides
B) Because the attacked trees are usually scattered, making control challenging
C) Because the insects only attack dead trees
D) Because the insects only infest the roots underground

Because the attacked trees are usually scattered, making control challenging

What is the best management practice to reduce losses to wood borers?

Prevention, Keeping trees healthy and vigorous will allow them to fight off invading borers. 

Pine sawyers develop in

fresh cut, felled, dying, or recently dead pines

What parts of the tree do young larvae feed on?

A) Leaves and flowers
B) Inner bark, cambium, and outer sapwood
C) Roots only
D) Outer bark and needles

Inner bark, cambium, and outer sapwood

What do young larvae create as they feed, and what do they fill these with?

A) Large tunnels filled with water
B) Surface galleries filled with coarse, fibrous borings and frass (insect excrement)
C) Nests filled with leaves
D) Holes filled with sap

Surface galleries filled with coarse, fibrous borings and frass (insect excrement)

Why are Pine Sawyers called “Sawyers”

noise made while feeding

The beetles can carry the

pine wilt nematode

What type of trees does the native two-lined chestnut borer primarily attack?

A) Pines, firs, and spruces
B) Oaks, chestnuts, and beech
C) Maples, birches, and willows
D) Palms and tropical hardwoods

Oaks, chestnuts, and beech

When does the two-lined chestnut borer typically attack trees?

A) Only healthy, vigorous trees
B) Only newly planted seedlings
C) Trees that are stressed, hastening their decline and death
D) Trees during winter dormancy

Trees that are stressed, hastening their decline and death

When are trees most susceptible to attacks by certain bark beetles or pests?

A) When trees and stands are healthy and vigorous
B) When low-vigor trees or broken branches are present, especially after drought or defoliation stress
C) Only during the winter months
D) When trees are overwatered

When low-vigor trees or broken branches are present, especially after drought or defoliation stress

What conditions can lead to outbreaks of these pests?

A) Mild and stable weather conditions

B) Severe stress conditions such as drought or defoliation

C) Regular pruning and thinning of trees

D) High nutrient availability in the soil

Severe stress conditions such as drought or defoliation

Describe the Emerald Ash Borer.

a dark metallic green beetle about in color, 1/2 inch in length and 1/16 inch wide, that is May until late July

Describe the Larvae of a Emerald Ash Borer.

creamy white in color and are found under the bark.

What is the host range of a Emerald Ash Borer?

limited to species of ash trees.

When are emerald ash borer infestations typically detected?

A) Immediately after adult beetles emerge
B) Only after the entire tree has died
C) When the upper third of the tree shows dieback, often followed by the rest dying the next year
D) When leaves change color in the fall

When the upper third of the tree shows dieback, often followed by the rest dying the next year

What often occurs below the dead portions of a tree trunk after infestation symptoms appear?

A) The tree produces large numbers of shoots or sprouts
B) The tree stops all growth permanently
C) The bark thickens to protect the trunk
D) The roots die immediately

The tree produces large numbers of shoots or sprouts

The adult beetles typically make a ___‐shaped exit hole when they emerge

D

What is a possible sign of larval feeding on a tree?

A. Bark turning completely white

B. Vertical splits in the bark due to tissue response (s-shaped)

C. Leaves turning purple overnight

D. Smooth, unbroken bark surface

Vertical splits in the bark due to tissue response

Trees attacked by defoliators can be recognized by missing  foliage and uneaten leaf parts such as veins and petioles

 missing 

Leaf Feeders or Defoliators feed within a leaf, mining between the 

upper and lower epidermis.

How do defoliators impact trees?

reduces photosynthesis, interferes with  transpiration and translocation within the tree. 

Light defoliation doesn’t cause much damage, what happens when moderate to heavy defoliation occurs?

 reduce tree vigor.

The  impact on a tree varies with  

time of attack, tree species and  health, and single or repeated defoliations.

What do sawflies feed on?

 feed on conifers or deciduous trees in forest  and plantation stands. T

What do the adults of a sawfly resemble?

small broadwaisted  wasps

What do the larva of a sawfly look like?

resemble caterpillars but are usually without  hairs and have pairs of fleshy prolegs on the underside of  every segment on their abdomen (caterpillars normally have  four or fewer pairs). 

Which of the following best describes the larvae of commonly found sawflies?

A. Bright red, 3 inches long, and have wings
B. Greenish to dusky gray, 2/3 to 1¼ inches long, with stripes or spots
C. Completely black, less than 1/4 inch long, and smooth
D. Blue with no markings and over 2 inches long

Greenish to dusky gray, 2/3 to 1¼ inches long, with stripes or spots

What are possible consequences of periodic sawfly outbreaks?

A. Improved tree growth and increased fruit production
B. Minor leaf discoloration with no long-term effects
C. Loss of tree growth and sometimes tree mortality
D. Faster bark regeneration and branch development

Loss of tree growth and sometimes tree mortality

What do Redheaded Sawflies look like?

 a red head and a yellow‐white  body marked with six rows of black spots

What do the larva of a redheaded sawfly feed on?

found on trees from 1‐15 feet tall, where they feed

gregariously on old and new needles and on tender shoots of

these young trees.

What do Introduced pine sawfly look like?

a black head and black body  covered with yellow and white spots. 

What do the larva of a introduced sawfly feed on? What do they prefer?

prefer to feed  on the needles of eastern white pine but also will eat Scotch,  red, Austrian, jack, and Swiss mountain pine.

________ and  _________ have been attacked but usually are not heavily  damaged. 

Short leaf, Virginia pines

Defoliation is most severe in what region of the tree when infested with introduced sawflies? What happens if heavy infestation occurs?

the crown to upper half of the  tree but heavily infested trees can be completely defoliated.

If defoliation by introduced sawflies occurs after the formation of winter buds, what can happen to the tree?

many branches  or even the entire tree can be killed.

How many generations of sawflies occur each year?

A. One
B. Two
C. Three
D. Four

Two

What is the feeding behavior of young and older sawfly larvae?

A. Young larvae eat entire needles; older larvae only chew bark

B. Young larvae eat bark; older larvae switch to roots

C. Young larvae eat tender outer parts of needles; older larvae consume the whole needle

D. Both young and older larvae only eat the tree’s fruit

Young larvae eat tender outer parts of needles; older larvae consume the whole needle

When do introduced sawflies become full grown?

July

The second generation of this sawfly  feeds on both old and new needles during . 

August and  September. 

What does a European pine sawfly larva look like?

green and black striped  larva with a black head.

What does the larva of the European Pine Sawfly feed on?

previous year's

needles and does not damage new needles.

What do many species of caterpillars feed on?

deciduous trees in forest  and a few feed on conifers.

How many pairs of fleshy prolegs do most caterpillars have, and where are they located?

A. Three pairs on the thorax only
B. Five pairs – four on the abdomen and one at the end
C. Six pairs – two on the head, four on the abdomen
D. Four pairs – all located on the tail

Five pairs – four on the abdomen and one at the end

Describe the common oak moth caterpillar.

 brown with tan to black  blotches on the sides; there are diamond‐shaped markings  and slanted lines on its back.

How does the common oak moth caterpillar move and how big is it as an adult?

moves in a  looping manner and is about 1¼ inches long when mature. 

How many generations are their of the oak moth caterpillar per year and when are they active?

 one generation each year with the caterpillars active  from May to June.

What tree do the common oak moth caterpillars prefer?

White Oak

What increases the risk of damage from single tree defoliation caused by common oak moth caterpillar?

A. Presence of fruit on the tree
B. Multiple bird nests in the branches
C. Previous droughts or other stresses
D. Excessive sunlight exposure

Previous droughts or other stresses

What is the preferred host of the eastern tent caterpillar?

 feeds on trees in the genus Prunus;  black cherry is the preferred host. 

What does an eastern tent caterpillar look like and how big is it full grown?

black  with a white stripe down the center of the back. A row of pale  blue spots along each side is bordered by yellowish orange  lines. Full‐grown larvae are about 2 ½ inches long. 

Defoliation of a tree by a eastern tent caterpillar typically

leaf back out and suffer only minor growth loss.

What do forest tent caterpillar looks like?

 very similar to eastern tent  caterpillars but have a row of light keyhole‐shaped spots  down the center of the back rather than a stripe.

How many generations of forest test caterpillar are their per year, and when are they most active?

One, during the spring.

Describe the Fall webworm.

a hairy pale green to yellow caterpillar that is  about one inch long when full grown. 

How many generations occur per year with the fall webworm?

Two or Three

Do fall webworms have a diverse appetite?

Yes, they feed on more than 100 tree species.

What is a common sign of webworm activity in trees?

A. Brown powdery mold on leaves
B. Light gray, silken webs enclosing leaves and small branches
C. Holes bored into the trunk
D. Sudden leaf color change to bright red

Light gray, silken webs enclosing leaves and small branches

Describe the Orange striped Oak worm.

 black with eight narrow yellow  stripes along the length of the body.

What is a noticeable characteristic of the orange striped oak worm?

They have a distinctive  pair of long, curved “horns” behind the head.

Why is the economic impact of orange striped oak worm defoliation usually considered minor?

A. Because they only attack fruit trees
B. Because defoliation occurs late in the summer or fall
C. Because they are easily controlled with fertilizer
D. Because they never completely strip leaves from trees

Because defoliation occurs late in the summer or fall

What do pine webworms look like?

yellowish brown with two dark  brown longitudinal stripes on each side.

Where do the younger larva of the pine webworm live and where do the older larva live?

young larvae live/eat pine needles, while older larvae live in silken tubes that extend  through webs of globular masses of brown, coarse frass

What do the webbing masses from the pine webworm encase?

enclose the needles upon which the larvae  feed.

 At first, the webbing masses may be only one or two  inches long, what happens as larva mature?

Increases in size.

What happens to seedlings when pine webworms are infesting them?

Become completely defoilated.

Infestations of pine webworms on larger trees can cause _____ defoliation resulting in loss of growth and poor tree  appearance. 

partial 

Where is the spongy moth established?

Ohio, West Virginia, Virginia,  and Tennessee. 

What do the older larva of a Spongy moth look like?

yellow markings on the  head, a brownish‐gray body with tufts of hair on each  segment, and a double row of five pairs of blue spots followed  by a double row of six pairs of red spots on the back.

 Large numbers of caterpillars can __________ defoliate an area. 

completely 

How does defoliation from spongy moths affect different types of trees?

A. Both softwoods and hardwoods die after a single defoliation
B. Softwoods usually survive multiple defoliations
C. A single defoliation can kill some softwoods, but hardwoods typically require two or more defoliations to be killed
D. Hardwood trees are immune to defoliation damage

A single defoliation can kill some softwoods, but hardwoods typically require two or more defoliations to be killed

Established infestations of the hemlock woolly adelgid (HWA)  were discovered at specific locations in 

Harlan, Letcher, and  Bell counties in 2006.

Describe the HWA.

native of Asia is a 1/32 inch long  reddish purple insect that lives within its own protective  coating.

White, woolly masses that shelter these sap‐feeding  insects are at what area of the tree?

the bases of hemlock needles along infested branches.

The presence of the white cotton ball like sacs indicates what?

An infestation of HWA

What is the HWA a threat to?

eastern hemlock forests, and eastern and  Carolina hemlock of all sizes are susceptible. 

Along with hemlocks what are also at risk?

ornamental  plantings in urban settings are equally susceptible.