Database Reference
In-Depth Information
1 : Infected Populat ion
2 : Uninfected Fraser Fir
1:
1.00
1
2:
20 .00
1:
0.50
1
2:
19 .00
2
2
2
2
1:
0.00
1
2:
18 .00
0.00
4500.00
9000.00
13500.00
18000.00
Hours
Fig. 11.22
1 : Infected Populat ion
2 : Uninfected Fr aser Fir
1:
1.00
1
2:
20 .00
1:
0.50
1
2:
19 .00
2
2
2
2
1:
0.00
1
2:
18 .00
0.00
4500.00
9000.00
13500.00
18000.00
Hours
Fig. 11.23
rate for the desired results fell between 10% and 11%. At 11%, the Fraser fir popula-
tion suffered no casualties (other than the originally infected tree). However, with a
10% kill rate, the Fraser fir population showed signs of steady decline and eventual
demise. This indicated that a 10% kill rate was not large enough to control our pest
population.
An 11% reduction appears to keep the
Adelges piceae
numbers relatively sta-
ble, as they are no longer infecting new hosts. Also, there is virtually no difference
between a 98% kill rate and a much lower one, such as 11%. In contrast, a 5%
kill rate would require an inadequate amount of pesticide, negatively affecting both
populations without significant gain on the pest control front.
