Psyllid Attack on North

Dakota Black Ash Resource

Pest Survey Outreach Series

Presented by:

Dr. Phillip Mason, Pest Survey Specialist

USDA, APHIS, PPQ - North Dakota & Montana

United States Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Exotic Pest Alert:

The Psyllid Pest on Black Ash

Justin Knott, NDDA Justin Knott, NDDA

The Current Situation Report

Jeff Heintz, forester from the city of Bismarck, ND contacted the USDA, APHIS, PPQ Bismarck, ND office with an inquiry about the psyllid pest, and the damage the pest was inflicting on Black Ash and Manchurian Ash throughout Bismarck. The pest has since been found in eastern ND, following contact with Fargo agricultural officials.

The psyllids appear to be causing dieback, and predisposing the Ash to decline and premature death.

Similar infestations have been reported in western Canada, specifically Edmonton & Calgary, Alberta, in years dating back to 2000.

Psyllid Species Identified

The psyllids were tentatively identified as Psyllopsis

discrepans by Dr. Gerry Fauske, entomologist at the

NDSU Systematic Entomology Lab, Fargo, North

Dakota.

The psyllid identification has since been confirmed

by psyllid expert Douglass Miller at the USDA

Systematic Entomology Lab in Beltsville, Maryland.

Reports of Psyllids on Black Ash

Based on internet reports, Dr. Fry, entomologist with the Alberta Research Council, has likewise identified this same pest in Edmonton and Calgary, Alberta, Canada. The pest is believed to have been in Canada since 2000. In the Canadian infestations, the psyllid has also been attacking Black and Manchurian Ash.*

As listed in the book Psyllids of North America, a single report of Psyllopsis discrepans is listed as collected from Nova Scotia, Canada in 1921.

In addition to the above report, Douglass Miller at the SEL lab in Beltsville, MD reports that the psyllid has also been reported at various time this past century in Minnesota, New York and Rhode Island, although dates on specimens are sketchy, possibly 1907.

European Distribution of

Psyllopsis discrepans

Distribution Map Above Prior to Canadian and US Infestation.

Presence

Absence (or not yet reported)

Justin Knott, NDDA

Fauna Europea

Herbarium specimens indicate that this species has

been collected in US, (Circa 1907) in MN, NY, & RI.

Source: Douglass Miller, USDA, ARS SEL lab.

The Cottony Ash Psyllid Lifecycle Psyllopsis discrepans

From Canadian Reports:

There are two generations of this insect a year in Calgary, with

overwintering eggs hatching in late June. First generation

nymphs feed until about mid-July until reaching the adult

stage. Second generation eggs will be deposited in late July or

early August and a second generation of nymphs will feed

until late August. Second generation adults appear about this

time and females will deposit eggs on tree twigs to

overwinter*. Development times will differ in US, perhaps as much as thee

weeks. In ND adults began appearing in mid-June, suggesting a hatch around last

week of May to first week of June.

* City of Calgary Forestry Report

Psyllid Facts

Psyllids are homopteran insects and thus have tubular, sucking mouthparts, and are commonly referred to as jumping plantlice. Mature psyllids commonly jump when disturbed.

Psyllids are similar in appearance to cicadas, only in miniature.

Adults size is ~ 2 to 3 mm in length. Wings are held roof-like over the body of the psyllid. Nymphs are flattened and less active than adults, and are found on the underside of the leaves in a cotton like substance secreted by the psyllid.

Damage to the Ash leaves is primarily caused by feeding nymphs.

Adult females lay eggs that hatch and develop through about five wingless, immature nymphal stages before becoming winged adults.

Nymph Exhibiting Cottony Flocculent

Black Ash Distribution

Native Range of Black Ash

USFS

Photos: Dale Herman, ND Tree Handbook

Mancana Ash

Fraxinus mandshurica

Mancana Ash and Black Ash are widely planted as

boulevard trees throughout the region.

ND Tree Handbook, Dale Herman

Photos: Dale Herman, ND Tree Handbook

Susceptible Cultivars

Fall Gold Black Ash - Fraxinus nigra ‘Fallgold’

Mancana Ash - Fraxinus mandshurica ‘Mancana’

Northern Gem - Fraxinus x ‘Northern Gem’*

Northern Treasure - Fraxinus x ‘Northern Treasure’*

(*Cross between native Black Ash with the Manchurian Ash).

To date there are no reports of this psyllid feeding on Green Ash (Fraxinus pennsylvanica)

or any of its cultivars.

Mancana Ash

Healthy vs Damage

Healthy Infested

Infested Black Ash Visible from the street, with

greatly thinned crowns, and clumped foliage

from the twisted and gnarled infested foliage.

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ND Tree Handbook, Dale Herman

Psyllid Feeding Damage

Psyllid nymphs can be found in the cottony material (produced

by the feeding insect) on the underside of the curled leaf. Dave Nelson, NDDA

Dave Nelson, NDDA

Adults can be seen on top of this highly distorted foliage, along

with many nymphal castings from previous molts.

Adults

Nymphal Castings

Locating Adult Psyllids

While many adults can be

found on the foliage, the

majority of adults can be

found on the main stems and

trunk, as they seek mating

partners, as seen below.

Tom Stromme, Bismarck Tribune Tom Stromme, Bismarck Tribune

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Various Life Stages of

Psyllopsis disrcepans

1st generation adults lay 2nd

generation eggs on the mid-rib.

Eggs

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Nymphal stage found in cottony mass on

underside of leaves. Nymphal molts can be

found on either top or bottom of leaf.

Nymphal Castings

Mating Adults on Trunk

Tom

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Justin Knott

Justin

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Psyllid Damage on Black Ash

Phil Mason, USDA, APHIS, PPQ

Dave Nelson, NDDA

Dave Nelson, NDDA

More Psyllid Damage on Ash

Dave Nelson, NDDA Dave Nelson, NDDA

Phil Mason, USDA, APHIS, PPQ

Degree of Damage on Foliage

Serious Feeding Damage Healthy

Phil Mason, USDA, APHIS, PPQ

Evidence of Presence in 2004

Phil Mason, USDA, APHIS, PPQ Examination of some infested trees

indicates that the psyllid pest has

been present prior to 2005, possibly

2003.

The photos reveal evidence of prior

infestation. Previous years growth

is stunted from a heavy infestation.

Phil Mason, USDA, APHIS, PPQ

Pests Causing Similar Damage

James S

olo

mon

, US

FS

James S

olo

mon

, US

FS

Woolly Ash Aphid Damage

Ash Flower Gall Mite

Other pests cause similar damage on the

foliage and floral parts, so isolation of the

pest is essential for identification.

Information Sources

USDA-NRCS PLANTS Database / Herman, D.E. et al. 1996. North Dakota tree handbook. USDA NRCS ND State Soil

Conservation Committee; NDSU Extension and Western Area Power Admin., Bismarck, ND.

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7423.html

http://content.calgary.ca/CCA/City+Hall/Business+Units/Parks/Urban+Forestry/Elm+Scale+and+Ash+Psyllid.htm

http://www.faunaeur.org/index.php

http://www.iCanGarden.com

http://www.edmonton.ca/portal/server.pt/gateway/PTARGS_0_2_238_214_0_43/http%3B/CMSServer/COEWeb/hous

ehold/pest+management/CottonyPsyllidsonAsh.htm

http://www.bismarcktribune.com/news/topnews/top01.txt

Douglass Miller, Systematic Entomology Laboratory, USDA, ARS, PSI, BARC-West, Beltsville, MD

Photo Contributors

Dr. Phillip Mason, USDA, APHIS, PPQ

David Nelson, North Dakota Dept of Agriculture

Justin Knott, North Dakota Dept of Agriculture

Dr. Dale Herman, North Dakota State University

Fauna Europea (Map)

USGS, Plants Database (Map)

USFS (Map)

James Solomon, USFS

Tom Stromme, Bismarck Tribune

Justin Knott, NDDA

Dave Nelson, NDDA

Tom Stromme, Bismarck Tribune