Forest Health> Insects> Southern Pine Beetle
Florida
Division of Forestry
Southern Pine Beetle Aerial Survey Procedures |
Introduction
 Although
the southern pine beetle (SPB) is a native insect that
is often controlled by natural factors, SPB infestations
have a remarkable potential to grow rapidly (edges of
infested spots can expand by >50 feet/day) and cause
extensive pine mortality under certain conditions.
Because of this damage potential, the Division of Forestry
conducts annual aerial detection surveys to record the
location and size of SPB "spots" (groups of infested trees).
These aerial surveys should be accompanied by ground checks
and notifications to landowners/managers about the need
to control expanding SPB spots as soon as possible.
Early and rapid detection (and subsequent control) of
SPB spots is critical to preventing the development of
outbreaks, and for minimizing damage when outbreaks do
occur.
Timing and Frequency of
Flights
Each DOF District within the known range of SPB (Districts
1-12) is responsible for conducting at least one SPB aerial
detection survey of all its counties each calendar year.
In most years, this initial aerial survey is to be conducted
in late May or early June in accordance with a memorandum
(issued in May) to the District/Center Managers. Earlier
surveys may be requested by the Forest Entomologist for
areas where winter/spring SPB infestations are discovered,
or in areas where moderate to outbreak levels of activity
are predicted by the spring
Pheromone Trap Survey Forecast.
If no
SPB spots are detected during the initial May/June aerial
survey, no additional SPB aerial surveys need to be conducted,
unless SPB spots are later detected and confirmed
through another means (e.g., response to a landowner call,
ground detection, detection on a wildfire survey flight,
etc.). If SPB spots are detected on the initial flight, or
detected later through other means, follow-up aerial surveys
should be conducted monthly until no new spots are identified.
In counties experiencing outbreaks with rapid initiation
of new spots, flights should be conducted every 2-3 weeks
until no new spots develop. Follow-up flights can
be discontinued after November 1st. In
counties that experienced active SPB spots during the
year, at least one aerial flight should be conducted during
late December-mid January; otherwise flights are to resume
with the initial May/June survey. (top) |
Area of Coverage
The manner in which each District is covered in the survey
is up to the discretion of the District Manager or an SPB
Coordinator designated by the Manager. Managers may
choose to have each county forester survey their own county,
or to have pairs or groups of counties (where feasible)
surveyed in a single flight. Regardless of whether
counties are surveyed individually or in groups, SPB spot
data should be reported to the Forest Health Section on
a county-by-county basis (see Reporting
section below). Aerial surveyors should attempt to
cover all of the susceptible host type (pine areas) in a
given county; areas where pine is notably absent or very
sparse may be omitted. Close attention should be given
to mature, over-mature, and/or high density stands of loblolly
pine. Loblolly pine stands in flood plains or along
watercourses are notorious locations for SPB infestations
and therefore should be checked closely. (top) |
Survey Procedure
As long as the primary goals of the aerial survey are achieved,
the specifics of the procedure can vary depending on the
preferences and judgment of the forester(s) and pilot involved.
The primary goals of the flight are 1) to detect most or
all potential SPB spots in a given county, 2) roughly estimate
the size of each spot, 3) record the location of each spot
such that it can be visited on the ground and identified
in follow-up flights, and 4) determine whether previously-detected
spots have substantially expanded, been controlled, or gone
inactive. The following general guidelines are offered
for achieving these goals:
Equipment:
The observer(s) should consider taking the following items
in flight:
- Maps (or
aerial photos) of the area
- Pencil(s)
or grease pencil(s) for marking photos/maps
- GPS Unit
- Notepad
and/or small tape recorder
- Air sickness
sack or canister; air sickness remedy
Flight pattern, altitude, conditions:
To help ensure adequate coverage of the county/area, parallel
flight lines (N/S or E/W) may be drawn on the map(s) prior
to the flight and discussed with the pilot. Spacing
of flight lines will vary depending on the distance each
observer is able to accurately scan. The following
table indicates the percent of an area that can be surveyed
given two observers, one surveying from each side of the
plane:
|
Interval between
flight lines
|
Percent coverage if each observer can scan a
distance of :
|
|
½ mile
|
1 mile
|
1 ¼ mile
|
1 mile |
100 |
- |
- |
2 miles |
50 |
100 |
- |
2 ½ miles |
40 |
80 |
100 |
5 miles |
20 |
40 |
50 |
|
|
Ideally, flights should be conducted on clear days
with low wind velocities and minimal haze, and at an altitude
ranging from 1000 to 3000 feet. Lower altitudes
allow a greater ability to detect small spots, while higher
altitudes can allow for better visual orientation and
location of landmarks. Flights should be conducted
between 9:00 am and 3:00 pm to avoid long shadows, and
should not last more than 4 hours without landing to avoid
observer fatigue.
Recognizing SPB
spots:
SPB spots usually appear as distinct clusters of dying or
dead-and-dying pines. New spots that have just become
visible from the air may have only light green or yellow-crowned
trees. Older spots will have trees in various stages
of attack, grading in appearance from needleless (vacated
by SPB) to red-topped (mostly vacated), to yellow- and light
green-topped (actively infested), to green-topped trees
(recently infested) that are indistinguishable from unattacked
trees. The color of the crowns in the spot can indicate
if, how rapidly, and in what direction the spot is spreading.
See
An Aerial Observer's Guide to Recognizing and Reporting
Southern Pine Beetle Spots for more information.
Recording spot location and size:
The location and size of all spots with 6 or more red-topped
pines and adjacent yellow-crowned faders should be recorded.
Spots with fewer trees or only yellow-crowned trees may
be recorded at the observer's discretion if they look suspiciously
like developing SPB spots. Spots should be plotted
as polygons or points on a map or photo so that they can
be located on the ground and monitored on subsequent flights.
If possible, have the pilot fly over the spot and record
the lat/long coordinates using a GPS unit. Also, roughly
estimate and record the size of the spot in acres (or fractions
of acres), either in the plane or later based on the size
of the polygons drawn on the map. Acreage estimates
can be adjusted after the ground check if necessary. (top)
Assigning ground check priorities:
If detected SPB spots are so numerous that available personnel
and time will not permit ground checks on all spots, use
the following table to help assign ground check priorities
to each detected SPB spot. Ground check priority numbers
can be recorded directly on the sketch map:
|
Priority for
Ground Check |
Spot Classification |
| Priority 1 (high) |
More yellow than
red-crowned trees
In dense natural pine stand or in area with
past history of SPB outbreaks
Easy access or high salvageable volume
In plantation or other high value area
Threat to cross property lines and affect high
value stands |
| Priority 2 (breakout) |
Yellow-crowned trees in spot
previously reported controlled or inactive |
| Priority 3 (medium) |
More red-crowned than yellow-crowned
trees
Poor access or moderate salvageable volume |
| Priority 4 (low) |
Few yellow-crowned
trees
Infested pines surrounded by hardwoods or open
land
Difficult to locate on ground because of small
size or inaccessibility
In unmerchantable timber or with low salvageable
volume |
| from Billings
and Ward, 1984 "How
to Conduct a Southern Pine Beetle Aerial Survey" |
| |
|
For additional information and guidelines on SPB survey
procedures, consult How to Conduct a Southern Pine Beetle
Aerial Detection Survey by the Texas Forest Service. (top)
Landowner Notifications and Ground Checks
Identify the landowner of suspect spots within five days
after the flight. After identifying the landowner, immediately
(or within two days at the latest) notify the landowner
of the potential SPB activity on his or her property by
letter, phone, in person, or otherwise. Over the years,
individual counties have developed procedures and form
letters to tailor this notification process to their own
situation. For sample letters or suggested notification
materials, contact the Forest Health Section office.
Ideally, do a ground check (i.e. visit the site to confirm
the presence of SPB) on all newly detected spots as soon
as possible and before the next follow-up flight. However,
when spots are numerous, you may have to prioritize ground
checks using the criteria listed in the table above, or
based on landowner familiarity with/capability of dealing
with SPB.
The primary goals of the ground check are to 1) confirm
that the spot is actually an SPB spot rather than mortality
caused primarily by another bark beetle, insect, disease,
or causal agent, 2) evaluate the likelihood of spot expansion
based on presence of active and freshly-attacked trees
3) delineate a control buffer strip around the active
portion of spots, and 4) collect some basic stand measurement
data at the spot. Detailed guidelines for these activities
can be found in A
Field Guide for Ground Checking Southern Pine Beetle Spots,
USDA Agriculture Handbook 558. If the landowner resides
at the property, the ground check is also an opportune
time to discuss the situation with him/her and provide
information about control options.
During the ground check, take a few moments to roughly
estimate and record the following spot parameters and
information:
• Predominant pine species
• Avg. Basal area, height, and diameter - (don't
cruise the stand, just use 1-2 prism plots or ocular estimates)
• Predominant market size class (pulpwood, chip-n-saw,
or sawtimber)
• Landform (bottomland/flatwoods, sandhill/ridge,
or other terrain)
• STR or lat/long coordinate
• Adjust estimates of spot size if needed
• Note whether the spot is active, inactive, or
has been controlled.
Spots should be aerially surveyed or revisited at monthly
intervals following detection until they are controlled
or inactive. (top)
Reporting
Use the SPB
Activity Excel Spreadsheet to periodically record and
report SPB spot/infestation data to the Forest Entomologist
on a county basis. This reporting can be done by the county
forester(s) or others assigned the responsibility by the
District/Center Manager or SPB coordinator. The spreadsheet
is intended to be a tool for the forester to keep track
of activity in his/her county, as well as provide the Forest
Health Section with data on the extent and volume of SPB
impact in the state (as required by our Regional USDA Forest
Service cooperators). The spot parameter data is used to
determine what types of stands are most vulnerable to SPB
in Florida.
Update and submit the completed Excel spreadsheet to the
Forest Entomologist monthly during active years, or by November
of inactive years. The spreadsheet can be saved electronically
and emailed. Because the spreadsheet contains embedded formulas,
do not alter its format. Instructions for completing the
spreadsheet are included on one of the spreadsheet 'tabs'. Drop-down
menus are programmed into many of the columns to avoid typing. Please
contact the forest Entomologist with any questions regarding
the spreadsheet or reporting procedure. (top)
Online References
The handbooks referenced in the above text are located at
the following website managed through the University of
Georgia's Bugwood Network: http://www.barkbeetles.org/spb.html
Last Updated 24 March '04, Bud Mayfield, DOF Forest Entomologist.
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