Fungi as biocontrol agents Flashcards
1
Q
How does biocontrol work
A
- attempt to shift ecological equilibrium in favor of biocontrol agent
- helps to reduce population of target
2
Q
success story of biocontrol
A
- Opuntia stricta introduced in 1839
- recognized as a pest, growth spread rapidly in Australia
- 1912 search for natural enemies began
- Cactoblastis cactorum was immediately effective
- most opuntia stands gone by 1930
3
Q
Why haven’t fungi been used for biocontrol
A
- they may only damage the host rather than kill
- they may only reduce, rather than eliminate the target
- they may do both things slowly
4
Q
where can fungi be made effective in biocontrol
A
- control of arthropod and other invertebrate pests
- control of weeds
- control of fungi causing plant diseases or biodeterioration
5
Q
Coelomomyces (chytrid) characteristics
A
- obligate parasite of mosquito larvae
- can cause heavy mortality in populations of Anophele gambiae
6
Q
European blackberry (rubus) biocontrol
A
- rust fungus Phragmidium violaceum found to be a pathogen
- took two decades to suppress the spread of rubus
7
Q
Chondrilla juncea (rush skeletonweed)
A
- introduced in Australia in 1900
- spread rapidly through wheatlands
- rust fungus Puccinia chrondrillina was found to be a pathogen
8
Q
Aeschynomene virginica (northern joint vetch)
A
- infests rice and soybeans in the USA
- Endemic fungus Colletotrichum gloeosporioides as pathogen
- this was the basis for the first mycoherbicide
9
Q
What species has fungus served as a biocontrol against?
A
- European blackberry (rubus)
- Chondrilla juncea (rush skeletonweed)
- Aeschynomene virginica (northern joint vech)
10
Q
Benefits of using fungi as biocontrol agents
A
- extremely high repriductive capacity
- short generation time
- high specificity
- resting stages persistent and long-lived when host is absent
11
Q
General principles of using fungi as a biocontrol agent
A
- fungus must not be pathogenic to any economically or ecologically valuble organisms
- large amount of inoculum must be available
- timing and distribution important
- climatic conditions must favor growth , sporulation, and dispersal of fungus
