NACAA AM/PIC 2007Invasive Species:

Arrive, Survive, and Thrive

Chris DiFonzoField Crops Entomology

Michigan State University

‘Tiny Terrors’…The Soybean Aphid

the Soybean Aphid, Aphis glycines Matsumura

WinterWintereggs

MarchMarch

fundatrix

Secondary host:Glycine max(soybean)

JuneJune

JulyJuly

AugustAugust

oviparae

Primary host:Rhamnus spp.

(buckthorn)

FallFall

gynoparae

males

SeptSept

General Invasion Process

Arrive Survive Thrive

ARRIVE

Australia1999

JapanChina

Malaysia

Philippines

Thailand

Indonesia

Siberia

U.S. 2000

Trade and Tourists- direct flights from Asia

to Detroit, Chicago, Minneapolis

- increase in goods imported from Asia

ARRIE

2000Discovery

Based on anoriginal map by

Rob Venette,U.S. Forest Service

QuebecOntario

Introduction near Chicago?Aphids on plant material?

ARRIVE

Lack of Attention‘No-brainer crop’, ‘GM crop’Plant - RoundUp - HarvestDidn’t notice initial colonizers

Unexploited resource- secondary host (soybean) present- few economic soybean insect pests in the Midwest

SURVIVEARRIVE

Reproductive biology of aphids

Partheno-genesis

Born‘pregnant’

LiveBirth

SURVIVE

key:Presence

of thePrimary

host

Rhamnuscathartica- also nonnative &invasive

SURVIVE

D. Voegtlin (INHS), Quad Cities, Fall 2006

Ontario Quebec

2004distribution

THRIVESURVIVE

High ReproductiveCapacity

[Ragsdale lab, Univ. of Minnesota]

TempTemp68oF

77oF

86oF

95oF

DoublingDoublingtime time

(days)(days)2

1.51.5

2

---

TotalTotal# #

nymphsnymphs75

73

23

0

THRIVE

Tremendous ability to disperse

Avg 7,000 SBA per plant

Xplant population

X 90% alatoid

Potential for 800 million winged SBAgenerated per acre in early August.

Saginaw MI, August 1st, 2001

THRIVE

SBA landing on acalm morning.

East Lansing, 2005

Jays debug the Orioles.Insects take over SkyDome -Toronto crushes Baltimore

By John McCauley bluejays.com 8/3/2001

Toronto invaded by swarms of aphids.Clouds of bugs descend ondowntown streets Aug. 3, 2001.

“At least they weren't killer bees.”

Inadequate or poorly-timedbiocontrol

entomo-pathogensinfect late

THRIVE

native &non-nativepredators

can’t keep upsome years

lack ofparasitoids

THRIVEOutbreaks: 2001, 2003, 2005, some in 2007

Feeding from large #s of Aphids- sucks plant juices- specialized gut removes sugar- amino acid limited

Honey dew Sooty moldOther problems:

Impact of direct feeding (thousands of SBA per plant)

8-29-05Mervyn Erb

Early (June) infestation

Mid/late (July/Aug) infestation

Other impacts of aphid feeding- nutrients deficiencies (potassium) may increase loss

Kdeficient

adequateK

Local Impact – Yield Loss- plant height- leaf drop- # nodes per plant- # pods per node- # beans per pod- bean quality

0

10

20

30

40

50

60

UNT

D

17(-70%)

Yield, bu/acreSaginaw County, MI

2005

CRU

C30

(-40%)

CRU+

WAR

A

50

WAR

B36

(-30%)

Landscape Impact – Virus transmission

Avg # of aphids per trap in squash field(Peaks are made up primarily soybean aphids)

0

40

80

120

160

June July August

25 9 23 6 22 272 16 30 13

Western MI, 2003

# SBApertrap

SBA outbreak years(’01, ’03, ’05) in Michigan

Bean common mosaic

Cucumber mosaicWatermelon mosaicZucchini yellows

Potato virus Y

Economic & Social Impact – Increased pesticide use

1999 NASS Survey IL< 1%

1

OH<1%

1

IN0%

0

MI0%

0

MN0%

0

% acreage

# of products

(permethrin, chlorpyrifos)

2005 NASS Survey IL9%

OH18%

IN18%

MI42%

MN30%

(permethrin, chlorpyrifos, dimethoate, esfenvaleratebifenthrin, cypermethrin, cyhalothrin, cyfluthrin,methyl parathion, thiamethoxam)

% acreage

# of products ---------------------10---------------------

Post-detection of SBA

Concentrated on insecticides- scouting techniques- thresholds- improve application technology

Introduction of soybean rust:“the best thing that ever happened to soybean aphid”- increased focus on scouting, spray technology

AphidSuction Trap

Network- annual prediction

http://www.ncipmc.org/traps/

Medium term: Classical biocontrolForeign collectionClimate matching

Quarantine, testing Field release

Long term:Host Plant resistance

Pictures courtesy of Dr. Duchen Wang

MSU Soybean Breeder

Susceptible accession Resistant accession

A source for more information:Annals of the Entomological Society of America

Vol. 97, No. 2, March 2004

SPECIAL FEATURE ON SOYBEAN APHID

Soybean Aphid Biology in North America

Soybean Aphid in China

Assessing the SBA Invasion

Aphid identification

Suitability of Overwintering Hosts

Population Dynamics in China  

Soybean Aphid Predators

Prospects for Classical Biological Control