Walnut twig beetle - Pityophthorus juglandis
Effective: May 24, 2012 - December 31, 2013
Taxonomic Position: Coleoptera : Scolytidae
Pest Type: Insects
Pest Code (NAPIS): INBQTOA
This pest is a member of the following surveys: Exotic Wood Borer / Bark Beetle
These Approved Methods are appropriate for: 2013, 2012
Pest Information
CAPS Pest Datasheet: https://download.ceris.purdue.edu/file/
Pest Tracker: https://pesttracker.org/pest/INBQTOA
Human and Animal Pathogens Transmitted:
Not known to transmit any human or animal pathogens.
Pest Pathogens and Organisms Vectored:
Pityophthorus juglandis vectors the Geosmithia morbida fungus which causes "thousand cankers disease" (TCD) in walnut trees.
Survey

Approved Method(s)
Method Detail NAPIS Survey Method
Visual Follow instructions in the survey protocol: Thousand Cankers Disease Survey Guidelines for 2012 (USDA FS and PPQ, 2012). 3031 - General Visual Observation
Trap 105 - Multi-funnel Trap, 8 Funnel, Wet 3001 - General Trapping Procedure
Trap 107 - Multi-funnel Trap, 12 Funnel, Wet 3001 - General Trapping Procedure
Trap Spacing:
When trapping for woodborers or bark beetles, separate traps with different lure combinations by at least 30 meters (98 feet).
Method Notes:
June 12, 2012: The TCD Guidelines recommend using a 4-unit multi-funnel trap for convenience and to minimize cost. However, traps with a larger number of funnels (8 or 12) will also capture walnut twig beetles and are acceptable for use in surveys.

May 24, 2012: A trap and lure survey method has been approved for use for the 2012 season and beyond.

Approved Lure(s)
NAPIS Code Product Dispenser Effectiveness Compound(s)
55 Pityophthorous juglandis Lure polysleeve 50 days

Survey Recommendations
The following are recommendations for executing the survey using the approved methods for pest surveillance. The recommendations are developed through literature review and consultation with subject matter experts.
Key Diagnostic or Identification

Approved Method(s)
ID/Diagnostic:
Morphological. Pityophthorus is a large genus (>100 species in North America) and identification to species can be difficult since these are very small beetles and the distinguishing characters are often hard to discern without high magnification and good optics. To screen samples, refer to the screening aid by Labonte and Rabaglia (2010) and the TCD Guidelines for 2012. Suspect specimens should be submitted to an identification specialist for verification (follow the instructions in the TCD Guidelines for 2012).
Mistaken Identities:
Other native Pityophthorus spp.
References
  1. Cranshaw, W., & Tisserat, N. 2009. Questions and Answers about Thousand Cankers Disease of Walnut. Colorado State University, Department of Bioagricultural Sciences and Pest Management.
  2. USDA Forest Service and Plant Protection and Quarantine. 2011. Thousand Cankers Disease Guidelines for 2011.
  3. USDA Forest Service and Plant Protection and Quarantine. 2012. Thousand Cankers Disease Survey Guidelines for 2012.

If you are unable to find a reference, contact STCAPS@usda.gov. See the CAPS Pest Datasheet for all references.