Insect/Disease

Question 1

Forest Tent Caterpillar

Answer 1

NATIVE
Egg masses in upper canopy
spring/early summer defoliator
Gregarious for the first three instars
Fruit trees and broad-leaf trees

Question 2

Spongy Moth

Answer 2

EXOTIC - Europe
Silk production
Overwinters egg masses
Pupate into adult under leaves and bark
Mostly hardwoods but may consume and kill conifers
Pheromones’ are used to disrupt their mating

Question 3

Pine Engraver Beetle

Answer 3

Turning fork galleries
Infests upper part of the tree
Red boring dust can gather around base of tree
Pheromones and funnel traps used for control

Question 4

Mountain Pine Beetle

Answer 4

Infests middle of the tree
From Montana to the West Coast into Mexico
Turns them orange like fall

Question 5

Red Turpentine Beetle

Answer 5

Infests lower part of tree
1-2 year life cycle
Obvious signs - pitch tubes on stumps

Question 6

Emerald Ash Borer

Answer 6

EXOTIC - China
Feeds on phloem of ash
Natural Spread and through firewood
Chemical control but not practical for forest settings
Biological control by releasing wasps are still being analyzed

Question 7

Red Oak Borer

Answer 7

NATIVE
Hosts are most commonly red oak, black oak and scarlet oak
They extrude frass, discolored bark, wet spots and exit holes.
2 year life cycles
Woodpeckers are natural control and ants

Question 8

Asian Long-Horned Beetle

Answer 8

EXOTIC - Asia
Treat hosts with insecticide spray or remove hosts .5 miles
Dime sized exit holes
Hosts- Maple and Boxelder

Question 9

Two-Lined Chestnut Borer

Answer 9

NATIVE
Attacks weakened oak species across Minnesota, broken branches etc.
Feeds and lives in the inner bark and cambium layer of the wood.
Infested oaks die after 2-3 years

Question 10

Eastern Larch Beetle

Answer 10

NATIVE
Hosts tamarack and planted larch
Control - Sanitation
Larvae are damaging
Galleries under park and wood pecker damage
Yellow of lower crown

Question 11

Spruce Budworm

Answer 11

NATIVE
Hosts - spruce and fir
Control is commercial thinning, pesticides are not successful for forest management
30-40 year outbreak cycle

Question 12

Sugar Maple Borer

Answer 12

NATIVE
Host - sugar maple
Horizontal wounds
Larvae take two years to develop
Wounds create pathways for rot fungus
Remove infested trees and having a 10-15 year thinning cycle

Question 13

White Pine Weevil

Answer 13

NATIVE
Feeds on leaders of young white pine
Control and management including planting with a tighter crown closure
Pruning leaders and damaged branches can save the tree.

Question 14

Leaf Miners

Answer 14

Insects that feed within the leaves between the upper and lower layers of tissue.

Question 15

Shelter Feeding

Answer 15

Larvae use the leaves as shelter as they feed on the same leaves

Question 16

Disease Triangle

Answer 16

Virulence of pathogen
Favorable environment
Host susceptibility

Question 17

Pathogen

Answer 17

An organism that causes disease

Question 18

Armillaria Root Rot

Answer 18

Lives as a saprophyte in the soil until it finds a weakened host and turns parasitic
Leaves fruiting bodies near stump
Shoestring rot
Infests deciduous and evergreen trees

Question 19

Annosus Root Disease

Answer 19

Caused by native fungus
Main hosts are all conifers
Spreads by aerial spores that infect recently cut stumps
Flaky white under bark
Control - trenching and breaking up root graphs or cutting stumps with borax

Question 20

Hypoxylon Canker

Answer 20

Native
Host - aspen
Causes cankers and weakened portions on aspen, usually breaking off at 15ft up

Question 21

White Trunk Rot

Answer 21

Native
Host - aspen
Main sign is fruiting bodies on trunk, happens in over mature aspen so rotation is shortened to prevent loss from rot

Question 22

Butternut Canker

Answer 22

EXOTIC fungus - Asia?
Infects black walnut
No resistance yet
Considered endangered in Canada.

Question 23

Thousand Cankers Disease

Answer 23

NATIVE
Host - black walnut
Vectored by walnut twig beetle

Question 24

Dutch Elm Disease

Answer 24

EXOTIC
Vectored by elm bark beetles
Spreads in root graphs
Symptoms result from clogging vascular system of the tree and causes dieback within the crown
Control- Trenching and fungicide injections

Question 25

Beech Bark Disease

Answer 25

EXOTIC
Host Beech trees
Vectored by scale insect
Scale insect creates waxy coating around themselves for protection while feeding on sap.

Question 26

Oak Wilt

Answer 26

Caused by exotic fungus
Red and black oaks are affected
Range eastern states, Midwest and Texas
Vectored by insects carried from fungal mats and introduced into wounds by sap feeding beetles and oak bark beetles
Also spreads through root graphs
Fungicide injections an option for high valued trees
Root trenching

Question 27

White Pine Blister Rust

Answer 27

NATIVE
Pruning recommended for existing infections
Rust diseases require an alternate host to finish development
Currant is an alternate host
Can cause crown dieback