Insects and Disease - Caroll Guffy, UA Cooperative Extension Service

Forest Insect and Disease

Tree Farmer Conference Caroll Guffey

U of A Division of Agri.

Introduction Pine

◦ Pine Bark Beetles◦ Management Strategies◦ Pine Sawfly◦ Pine Diseases

Hardwoods Emerald Ash Borer◦ Oak Borer◦ Defoliators◦ Leaf insects◦ Disease

◦ Questions

Pine Bark Beetles

Three Main TypesSouthern Pine Beetle Turpentine Beetles Ips (3 different types)

Attack Loblolly & Shortleaf

All 5 occur throughout the SE

Southern Pine Beetle

The worst one of the bunch Builds up high populations fast 3 mm (1/8 inch) long & notched head In Arkansas, last outbreak about 19 years

ago Less common than other bark beetles

Symptoms of Attack

Bore into the living bark. Small pitch tube the size of a

small piece of popped popcorn.

Winding, S-shaped galleries, Blue-stain fungi in the

sapwood First indication is

discoloration of the foliage.

Photo by Forest Insects and Their Damage Photo CD vol. 1 no. 88. Gerald Lenhard, Louisiana State University.

Treatments

Spots usually have to be addressed to stop spreading

Salvage

Cut and leave

Cut and burn

Cut and spray

Descriptions of Ips Beetles Sixspined Ips

Largest Ips beetle: attacks lower 6 spines on hind end

Small Southern Pine Engraver Smallest: attacks top Second most destructive (SPB is #1) 4 spines on each side hind end

Eastern Fivespined Ips 5 spines on either side of hind end Size in between others Attacks middle portion of trunk

Signs of Attack

1st sign: yellowing foliagePitch tubes < ½ in. diameterWhen tree too stressed, only

visible sign is presence of brown dust in bark crevices

H, I or Y shaped egg galleriesExit holes look like bird shotBlue Stain

Spots usually die out during winter

Can get large before that time

May be too small to salvage

Treatments

Turpentine Beetle

The largest in the South Its size (5.0-8.0 mm) makes it easily

recognizable. Rounded hind end and no spines Attacks usually found on lower part of the

tree w/ pitch tubes > 1 in. diameter Not uncommon to attack largest tree Do not carry blue stain so tree might

survive

How to reduce likelihood of attack for all bark beetles

Encourage vigorous tree growth Wait until winter to harvest/prune when

beetle activity is high in your area Remove storm or lightening damaged

trees ASAP Minimize mechanical tree damage Most common in drought years

Pine Sawflies

Several different species◦ Black headed, Introduced,

Loblolly, Virginia, RedheadedLarvae attack last year’s

foliageCan stress treeUsually no control

necessary

Pine Diseases Blue Stain Needle Cast Rust

Blue Stain Usually caused by bark

beetles (injury) Will almost always kill

tree. Usually not noticed until tree “flags”

Will develop in freshly cut trees

Needle Cast

Aesthetic problemOften mistaken

Needle RustLooks worse Alternate host goldenrod

Hardwoods

Emerald Ash Borer

EAB in the US

EAB an exotic beetle found near Detroit in 2002.

Solid wood packing materials from Asia Ohio 2003 Indiana 2004 Illinois and Maryland 2006 PA and WV in 2007

EAB in the US (continued)

WI , MO and VA in 2008 MN, NY and KY in 2009 IA and TN in 2010 CT, KS and MA in 2012 NH, NC, GA and CO in 2013 NJ and AR in 2014 Pretty fast for a bug that can only fly 3-6

miles!

• Adults feed on ash foliage - cause little damage• Larvae feed on the inner bark of ash trees• Girdles and kills the tree

Cory Bostic 2014

Basal Sprouting

EAB Tree Protection

Not economical for forest trees Not recommended until EAB activity has

been confirmed within 15 miles of intended application site.

Usually recommended 6 weeks prior to emergence

Annual retreatment after initial treat Could result in the loss of all ash in N

America

Management Strategies

If present consider removing ash trees any time there is a harvesting or thinning operation

Do Not Plant Ash! Insecticide treatment for

shade trees

Red Oak Borer

Native insect: always present Record breaking numbers

In the past 8 insects/tree Some 600 insects/tree

Several factors Overstocked Older low vigor stands Shallow, rocky sites

1st noticed in Ozark National Forest

Damage

2 year life cycle Severe damage to

lumber/wood Low populations may

not kill tree Can weaken trees

Management Strategies

Encourage tree vigor Remove brood trees Insecticide treatment for

shade trees

Oak Defoliators

Leaf rollersWalkingsticksSkeletonizerForest Tent CaterpillarDamage can be severe &

lead to stressHealthy trees recoverMore common in dry years

Special leaf insectsJapanese BeetlesAphidsLeaf Miners

Hardwood disease

Hypoxlon Canker

Affect most oak speciesOther hardwoods also Id by sloughing bark Grayish slick placesBrown fungal sporesQuickly kills the treeUsually secondary to some

other stress (drought)No control except removal

Questions