How to Treat SPB Infestations with
Verbenone-Only

At this time verbenone is not registered for commercial use. It should be registered for commercial use by the EPA some time next spring. Verbenone is registered for experimental use. If you are interested in attending a training workshop in your state or if you are aware of SPB infestations that may be suitable for the verbenone suppression tactic click here.
  1. Use verbenone for halting the growth of SPB infestations between June 1 and October 31 or when the daily high temperature is 80 degrees or higher. SPB spots should be located in stands with at least 60% basal area of loblolly pine, pond pine, slash pine, Virginia pine, or shortleaf pine.  READ THE VERBENONE LABEL!

  2. The Verbenone-Only method is only recommended for expanding SPB spots within the diameter classes and numbers of infested trees indicated in Table 1. The spot should have at least one fresh-attacked (stage 1) tree (adult egg galleries < 1 in. in length) and potential for continued expansion. See "A Field Guide for Ground Checking Southern Pine Beetle Spots" for descriptions of SPB tree stages.

  3. Identify, count, and flag all fresh attacks (stage 1 trees) with one color of flagging (e.g.,pink). Flag all other SPB brood trees (stage 2 trees) in the spot with a different color of flagging (e.g., blue)

  4. With a third color of flagging (e.g., yellow), mark the boundary of a horseshoe-shaped buffer of unattacked trees to be treated with verbenone. The buffer should extend at least 40 ft. in front of the most recently-attacked trees (pink flags) and include at least three rows of uninfested trees in the direction of spot expansion ( see illustration below).


  5. Refer to the "Verbenone-Only" table below to determine the total (minimum) number of verbenone pouches needed to treat one spot. The number of pouches is calculated by matching the value in the left column (Average DBH) with the appropriate value in the top row (Number of Active Infested Trees). This will give you the minimum number of verbenone pouches needed to treat the spot. The number of active trees is equal to the sum of the number of stage 1 and stage 2 trees.


    6. Table 1. Recommended (minimum) number of verbenone pouches per spot and pouches per tree to treat a southern pine beetle spot with Verbenone-Only (at 40 ml/ft2).
    Average DBH (in.)
    Number of Actively Infested Trees
    10
    20
    30
    40
    50
    60
    70
    80
    90
    100
    110
    120
     6*
    50
    50
    50
    63
    79
    95
    110
    126
    142
    157
    173
    189
    8
    50
    56
    84
    112
    140
    168
    196
    224
    252
    280
    308
    335
    10
    50
    88
    131
    175
    218
    262
    306
    349
    393
    437
     
     
    12
    63
    126
    189
    252
    315
    377
    440
    503
     
     
     
     
    14
    86
    171
    257
    342
    428
    513
    599
    684
     
     
     
     
    Number of pouches= (mean dbh/2)2 x number of active trees x 0.1745.  Note: if the average DBH or number of infested trees falls between two values on the table, take the average of the upper and lower values to calculate the appropriate number of pouches needed.


  6. Using the Hundle hammer, attach verbenone pouches at 10-12 ft. above ground level to each fresh-attacked tree (those with pink flagging), then to all uninfested pines within the marked buffer. Attach verbenone pouches by the flap above the seal using a nail (or staple if Hundle hammer is not available) and continue adding verbenone pouches to uninfested trees in the buffer until the required number of verbenone pouches is installed. Verbenone pouches should be spaced equally around the circumference of the tree's bole, assigning the proper number of pouches to each tree depending on its diameter:

    Table 2. Number of verbenone pouches allocated per tree based on diameter class.
    DBH (in)
    ..4
    5-8
    9-14
    15-17
    18-19
    20..
    No. Pouches/tree
    1
    2
    3
    5
    7
    9

    Verbenone pouches may be attached to hardwood trees or dead snags present within the buffer to fill gaps of more than 25 ft. between pines. Use two pouches per hardwood or snag if the DBH is less than 6 in. and 4 pouches per hardwood or snag if the DBH is equal to or greater than 6 in.

  7. Apply all the verbenone pouches, making sure that minimum buffer requirements are met. The total number of verbenone pouches used may exceed the number indicated in the table in order to meet minimum buffer requirements. The verbenone buffer may encircle small spots, but should be widest adjacent to the most recently-attacked trees.

  8. For each treated spot, record pertinent information including treatment method, average DBH, number of infested trees, number of verbenone pouches used, date of treatment, and names of applicators. Click here to print a sample data sheet.

  9. Spots should be checked two weeks after treatment and again three weeks later to verify control. An infestation is inactive when SPB have vacated all infested trees and no new attacked trees are evident. If the spot expands beyond the treated buffer, retreat with an additional verbenone buffer or other approved SPB control method. If the spot does not expand beyond the treated buffer within six weeks but fresh-attacked trees are present, it may be retreated at that time. Monitoring should continue until the spot is inactive or retreatment is necessary. After the spot becomes inactive, remove and properly dispose of all old verbenone pouches and nails.

Untreated SPB Spot
(Direction of Spot Expansion )

 

Note: Whereas the yellow-and orange-colored trees shown above represent somewhat the actual color change found in stage 2 and 3 trees, the lighter- colored fresh attacks shown above are not representative of fresh-attacked trees in the field. In the field an attacked pine will generally not change color until after SPB eggs hatch, i.e. early stage 2 trees. The light green color seen above is simply for illustrative purposes.


Treated with Verbenone-Only
(Direction of Spot Expansion )


Verbenone Precautions


Product Description

Before You Leave...

Be sure to print out a sample data sheet for the verbenone tactic

Review the procedures for treating SPB Spots with Verbenone-plus-felling.


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