Transcript Douglas fir Needle Midge, Contarinia pseudotsuga, a new

Sarah Pickel
- PA IPM Program
PA Department of
Agriculture
 Diseases
• Diplodia Tip Blight
• Rhabdocline Needle Cast
• Swiss Needle Cast
• Leader Death
 Insects
• Bagworm
• Cooley Spruce Gall Adelgid
• Cryptomeria Scale
• Douglas-fir Needle Midge
• Elongate Hemlock Scale
• Fir Coneworm
• Mites – Eriophyid (Rust) and
Spruce Spider Mites
• White Pine Weevil
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
Managing a problem is
much easier when that
problem is just beginning.
The farther along a problem
becomes, the more extreme
the solution may be.
Does your farm have
someone designated to
conduct pest monitoring?
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
Fungus affecting
only Douglas-fir
Yellow defined
spotting on current
year’s growth first
visible in October.
Generally starts on
lower branches of
tree.
March 7
May 6
End of June
Detection - Look in areas that remain wet:
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Low lying areas
Shady areas
Along tree lines with more mature trees
Northern exposures
Around ponds
Areas with poor weed control
Tightly spaced trees
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Extremely damaging disease.

Only occurs on Douglas-fir.
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Intermountain provenances
most susceptible. (Lincoln)
Distribution:
• Australia
• Europe
• North America
Endemic in natural range
(PNW).
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Introduced to other areas.

PA -1973 in Susquehanna Co.
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Needle tips of current
and/or previous years
needles yellow and
gradually brown during
late winter
No distinct margin
between healthy and
infected needle
Mottled appearance
September


Looks like drought stress or
winter burn.
Needles eventually defoliate
and leave interior of tree bare.

Stunted growth.

Loss of vigor.

Some growers report almost
complete needle loss to young
trees and subsequent death.
Management:

Fungicides used for management are
protectants, so the product needs to be
applied to new growth to prevent infection.
Management:
 Carefully scout symptomatic trees in spring for
bud break and fungus sporulation.
Four fungicide applications (most commonly Bravo)
#1 - when 1st trees in plantation break bud.
#2 - one week after first application.
#3 - two weeks after second application.
#4 - three weeks after the third application.
 4th application necessary only if spring is prolonged
by cool, wet whether, or Swiss needle cast is
detected.
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All fungicides are protectants.
Timing of first application is critical. Carefully scout
symptomatic trees in spring for bud break and
fungus sporulation.
Five fungicide applications *
• #1 - when trees in plantation break bud.
• #2 through #5
– 7 – 10 day intervals
– Carefully monitoring weather conditions
– Later sprays most important for Swiss
Paul Shealer, 2014
 Plant
coastal varieties - Shuswap
 Weed control for good lower branch
coverage
 Removal of old/overgrown trees
 May take 2 -4 years to “clean up a tree”
 Good timing
• Monitor for bud break
• Weather conditions (prior to wetting)
 Right
product
 Thorough coverage
 Disease
infecting a
season’s new shoots
 Infection
begins in
spring and continues
to spread throughout
season.
 Spread
in wet
weather
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
Hosts: Austrian
and Scotch pines
(Damage
potential severe),
Douglas-fir
Symptoms:
browning of twigs
starting at bud,
wilting of new
growth, black
fruiting bodies
found under bark

Management:
• For light infestations, prune out damage and
remove from field. Be careful not to uses same
pruners to clip healthy twigs.
• For heavier infestation, make a few applications
beginning at bud break. Bravo (chlorothalonil) is
not effective against Diplodia.
– Heritage, Quadrid (azoxystrobin)
– Topsin (thiophanate-methyl)
– Kocide, Champ (copper hydroxide)
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Leaders become stunted,
needles drop and
eventually die.
One possible cause of
death is canker formation.
Temperature swings in
winter can cause
wounding on leaders.
Where these wounds
occur, diseases can enter
and form cankers.
Could also enter through
pruning wounds.
Jill O’Donnell, Michigan State University Extension
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Fungicides not effective in
controlling secondary
diseases entering.
Don’t plant Douglas in frost
pockets.
Prune leaders in late
summer or early fall to allow
plenty of time for wound to
heal.
Prune leader back to the
branch collar without
injuring the collar.
* Recommendations made by Jill
O’Donnell at Michigan State
University Extension.
: USDA Forest Service Archive, USDA Forest Service, Bugwood.org

 Hosts:
• Douglas-fir, Pine, Spruce
Cathy Thomas, PA IPM Program, PDA
– Any tree
Sandy Gardosik, Entomology Department, PDA
Late May – June: Larvae exit bags on silk threads.
Early
damage
Spray
targeting
larvae
LATE SPRING / MAY – Larvae
hatch inside the cases and exit to
begin feeding on needles.
OVERWINTER – Eggs are protected in
the case over winter and through spring.
THROUGHOUT SEASON – Larvae
continue to feed and grow.
Early Fall / September – Larvae pupate
and the male moths exit cases to
fertilize the females in their cases.
Fertilized females produce eggs.

Management:
• Physical – Remove bags from trees by hand before larvae
emerge in late spring.
• Bio-Rational – Apply a Bacilus thuringensis (Bt) spray in
early summer, targeting newly emerged bagworms.
– Javelin, DiPel
• Chemical – Apply a registered insecticide at the time of
bagworm emergence. Wait until majority have emerged to
spray, and make one application.
– Pyreth-it (Pyrethrin), Conserve & Entrust (Spinosad)

Small, sucking pests
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2 hosts:
• Douglas-fir – needles affected
• Blue Spruce – twigs & buds affected

Form protective waxy, wool-like
coverings outside of gall

On Douglas-fir
Kinked
needles
Adult with eggs
Fall/Early Spring:
Nymphs with no
wax
Nymphs on new growth
Brian Schildt, PA IPM Program, PDA
Sandy Gardosik, Entomology Department, PDA
Sandy Gardosik, Entomology Department, PDA
CLOSE TO BUD BREAK –
Adelgids develop eggs.
EARLY SPRING / APRIL – Nymphs
mature into adults and develop
protective waxy covering.
AFTER BUD BREAK – Eggs
hatch and nymphs move to
new growth. This process
continues through the season.
Spray
targeting
nymphs
OVERWINTER – EARLY SPRING –
Nymphs exposed on the needles.
OCTOBER – Nymphs will settle for
the winter on the needles (uncovered).

On Colorado Blue
Spruce
 Management:
•
Treat with dormant oil in late fall or early spring
when trees are dormant.
•
Or apply registered insecticide in early October
or before bud break in Spring to target
overwintering nymphs.
– Damoil (Mineral Oil), M-Pede (Insecticidal Soap),
Provado (Imidacloprid), Talstar (Bifenthrin), Movento
(Spirotetramat)
– Additional control options on the fact sheet Insecticides
& Miticides for Christmas Tree Pests.
Sandy Gardosik, Entomology Department, PDA
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Light orange, fly-like
midge
Long, delicate legs
Tiny – adults are 3 mm in
size
Carries out life cycle by
forming galls inside
Douglas-fir needles.
Olson, Plant Pathology, PDA
Tracey
Sandy Gardosik, Entomology Department, PDA
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Douglas-fir needle midge is spread
throughout much of the United States.
Has been a large issue in the
northwestern US.
If Douglas-fir is present, potential for
DFNM is there.
Adults emerge at end of
April – early May.
Eggs are laid about 5 days
after adult emergence and
hatch about 3 days later.
Gall becomes evident about 3
weeks after larvae enter needles.
About the 4th week in May.
Infested area swells on
bottom side of needle.
Larvae begin exiting needles in mid November.
Midge pupate and overwinter in the soil.
Spray
targeting
adults
About 5 days after emergence,
eggs are laid inside the buds.
BUD BREAK / APRIL – Adults
emerge to mate and lay eggs
in the new buds.
EARLY SUMMER - Galls in
needles become noticeable as
swollen, bent areas.
OVERWINTER - Pupae are in the
ground at the base of a tree.
NOV/DEC – Larvae exit needles
and drop to ground to pupate
Look alike: Cooley spruce gall adelgid
Sandy Gardosik, Entomology Department, PDA
Sandy Gardosik, Entomology Department, PDA
Tracey Olson, Pathology Department, PDA
RHABDOCLINE
NEEDLE MIDGE
Detection: Emergence Traps

Monitor adult emergence if infestation is high
• Scout Douglas fir in fall to detect infestation
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Simple Construction:
• Cardboard Box (keep flaps for anchoring)
• Mayonnaise or Peanut Butter Jar.
• Duct Tape
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Place at base of previously infested trees.
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Put traps out April 1st.
Adult Emergence Trap
Traps should be placed on the side of the
tree where the most damage was found
Sandy Gardosik, Entomology Department, PDA
As bud break approaches, check traps daily.
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Look for swarming midges in fields with
previous infestations.
DFNM will fly around the buds.
Management:
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Because of long, thin ovipositor, females can lay
eggs in buds before full bud break.
Usually too late to wait until 10% bud break
Orthene label allows for application up to 2
weeks before bud break.
•
•
•
•
Acephate (Orthene)
Azadirachtin (Azatin)
Chlorpyrifos (Lorsban, Whirlwind)
Lambda-cyhalothrin (Lambda T, Warrior)
Fiorinia externa (Ferris)
 SYMPTOMS:
•
Yellowed needles on lower branches,
beginning at trunk
•
Damage moves upward as population
increases.
•
Scale coverings on the underside of
the needles
•
Tree may appear flocked
•
Premature needle drop
•
Eventual branch and limb dieback
and death of tree with severe
infestations
 HOSTS:
•
Douglas-fir
•
Hemlock
•
Spruces
•
True Firs
•
Pines (less common)
Oval females produce
protective “elongate” covering.
THROUGHOUT SEASON – Eggs
are laid within female casing.
Spray
active
crawlers
Male scales mature into
adult winged insects
MALE
LATE MAY – Crawlers begin to
appear & continue to
throughout season
FEMALE
MARCH – MAY - As scales develop,
male and female armor differs.
NOVEMBER - MARCH – Scale
overwinters in several stages
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LIFE CYCLE:
• Similar to Cryptomeria, but all stages may be
present at anytime through the season.
• Crawlers can be active in April as soon as
temperature warms, but are most prevalent in Late
May / Early June.
MANAGEMENT:
Method supported by Penn State research:

When crawler numbers increase in Late May or Early June,
begin spray program of 3 applications every 4 weeks, or 4
applications every 3 weeks with a registered insecticide.
(This may not be necessary every season.)
Method supported by Connecticut research:
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A single basal trunk application of Safari prior to bud break
Alternative:
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Some growers have found success with only 1 or 2 sprays of
the newer product Movento
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Dioryctria moths
• Zimmerman Pine Moth -
Dioryctria zimmermani
(Grote)
• Fir Coneworm –
Dioryctria abietivorella
(Grote)

Hosts:
• ZIMMERMAN - Pines (Scotch,
Austrian, Eastern White),
Douglas- fir and spruce.
• FIR CONEWORM - Douglas-fir,
true firs, a variety of spruces,
pines and hemlocks.
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Larvae feed inside the trunk,
commonly at the site of a wound
or a limb junction.
Cause lots of sap flow and
weakening / breaking of limbs.
Rayanne Lehman, PDA
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Damage:
• Large amounts of sap
running from wounds.
• Large amounts of frass
(excrement) found at wound
site.
• Dead or dying branches or
leaders of trees, but no
wilting.
Sam Lovenwirth, PDA
Sam Lovenwirth, PDA
Sam Lovenwirth, PDA
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Management:
• Mechanical - Removing and destroying infested trees
before adult emergence. Should be done in early to
mid-July.
• Chemical –
 Zimmerman: Early Spring Application – targeting larvae before
they move inside the trunk (April); must penetrate foliage to the
trunk.
 Fir Coneworm: Mid Spring Application – targeting adults
before they can lay eggs (May). * Has been attempted by
growers but not tested by research.
– PRODUCTS – dimethoate, chlorpyrifos, endosulfan,
Bt (Dimilin)

Sarah Pickel
• Email: [email protected]
• Phone: 717-772-5227
• Address: PA Department of Agriculture
2301 North Cameron Street
Harrisburg, PA 17110

Christmas Tree Scouting Report
• Provide me with your email to be added to
distribution list Email List.
• Website: http://ento.psu.edu/extension/christmas-trees
• Hotline: 1-800-PENNIPM