Flashcards in Biological Control Deck (26)
What is biological control?
any non chemical control
what are some examples/types of biological control? (in general)
- sterilized male
- natural control
- mating disruption
- classical biological control
- microbial control
How does the release of sterile males work as a biological control?
sterile males are released --> females mate with sterile males and do not become fertilized --> no offspring
How are sterile males produced?
males are reared in large numbers and radiated enough to sterilize but not kill
In what species has sterilization of males been successful?
- screw worm
- codling moth
What is required for sterilization of males to work?
- assumes males still able to mate
- high ratio of sterile to fertile
- limited geographic distribution of bugs (small areas)
- LOTS of funding = increased taxes
What does sterilization of males work best on?
flies but has been tried on moths (codling moth)
How does mating distribution work?
1. identify pheromone used by insect
2. synthesize + set out pheromone so males cant find real females due to large amount of pheromone
3. females do not get mated and dont produce offspring
4. population declines
Pros of mating distribution?
- specific to one type of pest and can be very effective
- compatible with other controls
- no toxins
- no resistance to the method
Mating distribution works well on what?
What is natural control?
building up natural enemies in an area
- dont use pesticides
- provide other food sources (eg: hedge rows)
What insects are used as natural controls?
- ground beetles
- parasitic wasp
- minute pirate bug
What is inundative control?
rear natural enemies in lab and release in field or greenhouse
What is a problem with inundative natural control?
What is intraguild predation?
predators may prey on each other and reduce successful control
What is required to minimize intraguild predation?
- systems balanced with different interactions possible
- lab + field studies
- must understand ecological relationships between bugs
What is biological control?
foreign species is introduced and their population rises dramatically. Introduce another foreign species (their natural predators) in order to reduce + stabilize their populations
What is an example of the use of biological control? (Problem insect? Introduced insect? Result?)
Problem: cottony cushion scale - Introduced: vedalia beetle (ladybug-like) Result: saved citrus industry
What are the risks of classical biocontrol?
- hard to predict what introduced species are going to feed on (eg: predator may out-compete native species or prefer to feed on other species than intended)
What are the steps of biological control?
1. is the invasive species an ecological or economical problem?
2. is there sufficient support to initiate a biological control program?
3. find out basic biology (eg: identify weed properly, literature search etc)
4. Look for possible agents
5. Test host plants (look for feeding, egg laying and development
6. Introduce if everything checks out
What can biological control work on?
- introduced insect species
- introduced plant species
What is an example of a plant being controlled by biological control? How was it solved?
- gall flies which fed on seeds
- Beetle which fed on roots
- larinus minutus
What is microbial control?
use of insect diseases to control pests
Pros of using microbial control?
- more specific than chemicals
- reduced nontraget casualties
What does bacillus thurigiensis effect?