Week 5 Biological Control

Question 1

Define biological control

Answer 1

Using living organisms to control weeds- fungi, virus, bacteria, mites, insects, birds, fish

Question 2

Describe how weed populations change when a biological control agent is introduced

Answer 2

Effectiveness increases as weeds density increases
Exotic organisms work best to control exotic weeds
Takes a while to see effect and always lags behind the weed pop

Question 3

Outline positive benefits to implementing biological control

Answer 3

Environmentally SOund
Self sustaining
Cheaper in long term
Land managers don't need to make a decison
Used when other IWM controls don't work

Question 4

Outline negative aspects and disadvantages to biological control

Answer 4

;Only 30% of releases are successful
Not all weeds are suitable targets
High initial cost
Agents are slow to have an effect

Question 5

Cactoblastis are unusual is biological control

Answer 5

Prickly pear was introduced by settlers as fence, 24million Ha by 1920’s
1912-1926 Cactoblastis (argintinian moth) introduced and controlled it

Question 6

Pattersons Curse

Answer 6

Weevals - expect effect in 20-50 years

Fleabettle gets into roots

Question 7

Skeleton Weed

Answer 7

1971 plant pathogen as biocontrol agent and gall mite and midge

Question 8

classical biological control

Answer 8

Release control agents which establish and provide ongoing control

Question 9

inundative biological control

Answer 9

Mass production and release of control agents at regular intervals

Question 10

Outline the six protocols for releasing of biocontrol agents

Answer 10

Study biology and ecology of weeds
Explore likely agents in native range of weeds
Detailed studies of likely agents OS
Introduce to aust - quarantine
Cost Benefit analysis
Strategic field release

Question 11

Outline what role legislation can play in controlling weeds

Answer 11

Restrict human dispersal of weeds - clean machinery at boreders
If vector natural (bird) legislation to decrease spread

Question 12

Legislation May

Answer 12

Impose restrictions on movement and sale of plant

Specify responsibilities for control and coordination

Question 13

Outline how a weed is defined as being noxious

Answer 13

Invasiveness
Impacts
Potential for spread
Socio economic and Envrio Value

Question 14

What is meant by a weed of national significance

Answer 14

20 spp ID’d as top national [riorities for management strategies
Require concentrated control

Question 15

Noxious weeds

Answer 15

Declared/proclaimed weeds

Landholders must control by law

Question 16

Control Class

What ones are notifieable weeds

Answer 16

1,2,5

Question 17

Objectives of Noxious weed Act

Answer 17

ID weed (noxious)
Specify control methods
ID who is responsible
Provides frameworks so all groups can work together

Question 18

How does a weed become noxious

Answer 18

Advisory Committee recommends it to the minister