Fire Ant Control Centre

K. P. Plowman, N. Kunsmann J . Somerville, J . Holley, M. Mc Naught, S. Marsden and C. Vanderwoude

Red Imported Fire Ant An Australian Experience

Fire Ant Control Treatment Areas

Treatment and Surveillance Areas

Port (Air and Sea)Eastern Area

Wellington Pt

Wacol/RichlandsWestern Area

Swanbank

South west

Origins

Chemical markersHydrocarbonsVenom Alkaloids

Genetic markersGp9 (Social forms: Gp9BB monogyne,

Gp9 Bb polygyne)Microsatellites Mitochondrial DNA (mtDNA)

Hydrocarbons (n = 67)Venom Alkaloids (n = 67)

USA

Other

Microsatellites ( 4 loci, 20 allelles

East West

0

10

20

30

40

East West

Social Forms (n = 46)

Polygyne

Monogyne

Origins

0

20

40

60

80

100

120

Num

ber

East Wellington

Pt

West

Haplotypes (mt DNA)

Clade 2

Clade 1

Origins

43% of fire ant sites found on recently cleared land (includes a buffer of 25 metres) used for urban development (7% of treatment area)

93% of fire ant sites fell within 1 km of this recently cleared land

Preferred Habitat

An Estimation of the Mode of Dispersion

Modes of Dispersion to I nfected Properties I dentified

March - J une 2003(n = 219)

Flights

8%

Asssisted

25%

Unknown

67%

Assisted

47%Assisted and

in New

Development

s

37%

Flights

16%

Breakdown of ‘known’ modes of dispersion

Native Ant Fauna

Average Abundances of Ant Genera South

Ripley

0

20

40

60

I ridom

yrmex

Rhyt

idop

oner

a

Para

trec

hina

Mon

omor

ium

Pheid

ole

Noton

cus

Polyr

hach

is

Acrop

yga

Brac

hypo

nera

Other

s

Genera (n = 23)

Perc

ent

Abun

danc

e

Response of Native Ants to Small Fire Ant Nests

Iridomyrmex spp and Rhytidoponera metallica (complex)

Equal numbers

– Native ants more likely to initiate an attack

– Total fire ant mortality within 15mins

Equal Biomass– Fire ants initiated more attacks – Native ants observed avoiding confrontation– Fire ants ‘ganging up’ on native ants

Interaction

0%

20%

40%

60%

80%

100%

Percent Abundance

A

2001

B

2001

C

2001

A

2002

B

2002

C

2002

A

2003

B

2003

C

2003

Spring

% Others

% Paratechina

% Rhydtidoponera

% I ridomyrmex

% S. invicta

0

20

40

60

80

100

120

140

160

180

Aug

Sept

Oct

Nov

Dec

Jan

Feb

March

April

May

June

July

August

Sept

Oct

Nov

Dec

Mm

0

2

4

6

8

10

12

14

16

Days

Rainfall mean (1929- 2001 ) Mean no wet days (1929- 2001)

Monthly Rainfall and Number of Wet Days August 2001 to December 2002

and Average Monthly Rainfall and Number of Wet Days

0

50

100

150

200

250

Aug

Sept

Oct

Nov

Dec

Jan

Feb

March

April

May

June

July

August

Sept

Oct

Nov

Dec

Mm

0

2

4

6

8

10

12

14

Days

Rainfall (2001- 2002) Wet days (2001- 2002)

Days of Rain and Times of Flights Observed in the Field (west)

0

10

20

30

40

50

60

Jan 12

002

26

3 6 23

26

Marc

h 12

2002

3 24

29

April 12

002

3 12 14 18 29

May 12

002

4 9 26

30

Mm

0

5

10

15

20

25

30

35

40

June3

2002

5 9 July2

12002

Aug2

2002

18 21

23

26

Sept8

2002

18 25

11 22

28

16 29

Dec5

2002

11 22

25

27

30

Mm

0

5

10

15

20

25

9 10 11 12 13 14 15 16 17

Time (Hours)

Perc

ent

Act

ivit

y

Summer Autumn Spring

Daily Foraging Activity in Summer, Autumn and Spring

Summary

• Fire ants (monogynes and polygynes) in south east Queensland appear to have originated in the USA.

• The intensity and rate of the infestation may have been tempered by the: – drier than usual conditions effecting number of flights

and possibly the level of foraging and food available in the warmer months;

– the presence of substantial numbers of polygyne colonies;

– and the impact of local ant fauna attacking small colonies.

• The infestation has been assisted by increase in clearing, new residential development and the movement of materials.

Our Thanks To

• Dr Robert Vander Meer• Dr Ross Crozier• Dr Jane Hughes • FACC colleagues, in particular

Brenda Gooding, Craig Jennings, Evan Harris and Lynne Griffin

Geographical Distribution of Social Forms and Haplotypes Within the

Treatment Area 

Social Forms Haplotypes

Polygyne Monogyne Clade 1 Clade 2

East 0 100 74 26

West 70.5 29.5 94 6

Comparison of Rainfall 1997-2002 with Average Annual

Rainfall (1929-2001)

0

200

400

600

800

1000

1200

1997 1998 1999 2000 2001 2002

Year

Mm

Annual Rainf all Mean Annual 1929-2002

Distribution of Samples Analysed Chemically and Genetically

Distribution of Social Forms Within the Treatment Area

0

20

40

60

80

100

Lug

gage P

t

Rich

land

s

Mog

gill

Darra

Rive

rhills

Wacol

Elle

n Grove

Carole

Park

Perc

ent Polygyne

Monogyne

Seasonal Foraging

0

10

20

30

40

50

60

70

April May J une J uly August September October

Month

Average %

G

ranule

s R

em

oved

Treatment Underway

Healthy nest -not yet treated

Chemical and Genetic Characteristics of Selected Colonies Within the Treatment Area

Cuticular Venom

Social Form Microsatellite Mt DNA

Hydrocarbons Alkloids classification Haplo types

Type 1 Type 2 Monogyne Polygyne Clade1 Clade 2

Areas Port/Airport 15 1 7 0 Set 1 29 14 Wellington Point 3 - - - - 11 0 Wacol/Richlands/ Moggill 49 3 12 27 Set 2 107 7 Total (nests/ 67 67 19 27 47 147 21

samples)

Unrooted maximum likelihood tree of the three Australian populations of Solenopsis invicta together with known

North American populations and small samples from North and South America.

Maximum and Minimum Temperatures (average 1929-2001) and 2002

0

5

10

15

20

25

30

35

J an Feb M A M J une J uly A S O N D

Months

Mean m

onth

ly T

em

pera

tres

(C)

Max (av) Max (2002)

0

5

10

15

20

25

J an Feb M A M J une J uly A S O N D

Months

Mean M

onthly

Tem

perature (C

)

Min (av) Min (2002)

Foraging

0

2

4

6

8

10

12

9 10 11 12 13 14 15 16 17

Time (hours)A

vera

ge N

umbe

r of

Ant

s at

th

e Ba

it

Summer Autumn

0

5

10

15

20

25

9 10 11 12 13 14 15 16 17

Time (Hours)

Perc

ent

Act

ivit

y

Summer Autumn Spring