New Pest Response Guidelines - Phytosanitary Resources

Noctuidae: Spodopotera
Chapter 4. Survey Procedures
25
square
miles
9
square
miles
Initiate
sampling
here.
Figure 4.1.Trapping scheme. Begin by setting 36 traps per square mile
where spodoptera have been detected. Each block represents one
square mile.
Monitoring survey
Use a monitoring survey to evaluate the effectiveness of an action taken to
contain, suppress or eradicate the pest. Use the same survey tools as detection
and delimiting surveys.
Traceback investigation
Use a traceback investigation to locate the source of an introduction after
spodoptera has been detected. Tracebacking helps to determine if an isolated
detection is spurious—for example, the moth was conveyed into an area by air
currents—or if it is evidence of an established population. Typically, if a
single adult spodoptera is found in an area far removed from a port of entry, it
is likely that it was transported to the site. The same is true for isolated
detections during cool seasons.
Use wind field maps to plot the possible path of the moth. Calculate the
estimated day and time of arrival (based on the circumstances at the site and
likely air mass movements) and work backward in time and space to construct
a logical path.
Site circumstances that provide clues to the estimated time of arrival include
the following detections:
• Associated with the arrival of a weather system
• Of adults with no evidence of larval feeding
21