New Pest Response Guidelines - Phytosanitary Resources

Noctuidae: Spodopotera
Chapter 4. Survey Procedures
• Located in inland locations away from obvious ports of entry
• That end abruptly
• Of a new generation or stage in the life cycle
• Of sudden outbreaks or increases in numbers not associated with local
breeding populations
Once the path of the moth is plotted, carry out surveys along the path until the
likely introduction site is located. Likely origins include port environs, areas
where over-wintering is possible, or agricultural areas where hosts are
abundant. Allowing for the imprecision of this method, surveys add weight to
conjecture about the origin of an introduction.
Computer generated atmospheric trajectory analyses are available to help
identify potential sources of infestation and to trace the probable movement of
plant pests with air masses. One such program is the Branching Atmospheric
Trajectory (BAT) available from:
National Climatic Center
Data Base Administration
Box 34, Federal Building
Asheville, North Carolina 28801
http://www.ncdc.noaa.gov/oa/ncdc.html
Visual inspection of plants
Eggs
Larvae
Select plants that are at approximately equal distances, unless damaged plants
are observed. Give priority to plants with partly or completely eaten leaves or
flowers, gnawed shoots, fallen stalks, fallen or rotting fruit, gnawed heads, or
that exhibit poor growth. After checking the cropped area, examine field
borders, fencerows, and ditch banks for hosts. If hosts are found, take a
separate survey, particularly if the location is within the core area.
Follow a similar sampling pattern for each field surveyed (Figure 4.2). Collect
samples at least 75 feet from the edge of five different locations in the field.
At each sample location, inspect at least 10 plants from three adjoining rows
(or at equivalent distances apart). Collect eggs and larvae with sufficient host
for rearing purposes, if necessary.
Visual inspection is the best method to use when looking for eggs. Look for
clusters of 30 to 300 eggs covered with scales, on the underside of leaves near
growing points of the host.
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