A Systems Approach for Peach Twig Borer (PTwB) for Australia

The systems approach for Peach twig borer [Anarsia lineatella (PTwB)] will consist of orchard monitoring and treatment; fruit cutting in the orchard; fruit cutting in the packing facility; and the regulatory inspection.

1. Growers who plan to export apricots, nectarines, peaches, plums, or their hybrids to Australia must participate in the Systems Approach Program in accordance with the terms established in this document.
    
2. For the purposes of the systems approach work plan, orchard is defined as “a continuous planting of a single commodity that is not separated by a physical barrier (for example: ranch road, canal or highway)”.
    
3. Mandatory spray program:
   1. Mandatory dormant/delayed dormant and bloom spray aimed at Peach Twig Borer (PTwB).
   2. Dormant or delayed dormant sprays must be applied before first bloom
   3. Bloom sprays are to be applied up to one inch leaf growth
       
4. Field trapping, degree-day accumulation, and treatment:
   1. Trap type: Use traps with long lasting pheromone lures (a minimum of 6 weeks) to monitor PTwB.
   2. Timing of trap placement: Traps must be placed in the orchards before the emergence of the first PTwB generation and no later than March 20, San Joaquin Valley, and April 1, Sacramento Valley. For the Pacific Northwest States , traps must be in place no later than May 1.
   3. PTwB Trap Density: Determine the number of traps needed in the orchard by the following chart:
       

      PTwB Trapping Density

      Number of Acres	Number of Traps	Number of Acres	Number of Traps
      0 to 10	2	51 to 60	6
      11 to 15	3	61 to 70	7
      16 to 40	4	71 to 100	8
      41 to 50	5	> 100	Add 1 trap per 20 acres

      
       
   4. Trap placement: Hang traps 6 to 8 feet high, 1 to 3 feet inside the canopy in the north quadrant of the tree, in the shade, and at least 5 trees in from the edge of the orchard.
   5. Trap monitoring and maintenance: Check traps twice a week until the biofix is established; thereafter, check traps weekly.
      1. Remove trapped insects from the trap bottom after counting and record the trap catch on a monitoring form.
      2. Replace trap bottoms monthly or sooner if they become covered with debris.
      3. Follow manufacturer's recommendations for replacing pheromone dispensers.
      4. Pheromone must be changed according to the manufacturer’s label. Do not place other types of pheromone (e.g. codling moth) into the PTwB trap.
   6. Phenology (degree day or DD) model
      1. “Biofix” for this option is described as (2) or more PTwB moths trapped within a 7-day period. The biofix is used to control PTwB with pesticide sprays that are timed with the PTwB phenology model.
      2. The log book of minimum/maximum temperatures or thermograph. records/charts or electronic recorded data must be available for review upon request by USDA and County (California) or State (Pacific Northwest) officials.
   7. Treatments: Treatments should be applied 400DD to 500 DD from the beginning of the flight in each generation. If the fruit has begun to color, however, treat at 300 DD.

      If no moths are caught in the pheromone traps during the whole season, if shoot strikes are less than 3 per tree, and if no larvae are found during the orchard survey, no in-season pesticide sprays have to be applied.

   8. Records: Trap inspection records shall be available for review during the season upon request of USDA, State, or County Agricultural Commissioner personnel. Such records must be updated until ALL fruit from the orchard has been harvested.
   9. In order to certify fruit for Australia, trap inspection records and PTwB pesticide spraying records must be available in the packing facility during the development of the export season and will be reviewed prior to phytosanitary certification.
       
5. Orchard shoot strike survey and fruit cutting: Carry out a field inspection, including a shoot strike survey, and pre-harvest cutting for each one of the lots of peaches, nectarines, apricots, plums, or hybrids of the four species that will be exported to Australia.
   1. The shoot strike survey and fruit cutting must be done no more than 5 days prior to harvest and before harvesting any fruit from the orchard.
   2. The number of trees to be surveyed will vary by orchard size as follows:
       

      Number of Trees to be Surveyed for Orchard Fruit Cutting

      Number of Acres	Trees Surveyed	Number of Acres	Trees Surveyed
      0 to 40	60	61 to 65	79
      41 to 45	64	66 to 70	83
      46 to 50	68	71 to 75	86
      51 to 55	71	76 to 80	90
      56 to 60	75	> 80	Over 80, add 1 tree per 2 acres

      
       
   3. In each case, the trees will be checked for shoot strikes, and five (5) fruit from each tree surveyed will be cut and examined for PTwB. The fruit must be taken from the top portion of the tree (Samples taken from the lower and middle portion of the tree are not acceptable.)
   4. If more than an average of 2 shoot strikes per tree and/or one live PTwB larva are found during the orchard shoot strike survey and fruit cutting, the grower lot will be suspended from export to Australia for the remainder of the season.
   5. The Pest Control Advisor must be present or readily available.
       
6. On Line (Packing Facility) Cull Cutting
   1. The packing facility must have at least two State or county trained “technical” employees responsible for fruit cutting during the packing process.
   2. Technical employees shall cut and examine 300 cull fruit per day from each lot intended for shipment to Australia. The fruit that is cut should be representative of the entire harvested lot.
   3. Culls for cutting cannot be held longer than five (5) days.
   4. If no fruit for an entire pack date is shipped to Australia, cull cutting does not need to be completed.
   5. Once cull cutting has been started in a lot, all 300 fruit must be cut no matter how many live larvae are being found unless the packing facility chooses to remove the lot from the program for the season (e.g. numerous finds of larvae other than PTwB).
   6. The county or State regulatory officials will monitor the cull cutting activity.
   7. All live larvae found must be presented to a State or County regulatory official and identified by the State or County, recorded on the “Packing Facility Inspection Log” prior to presenting the lot for export certification for Australia. All live larvae found must be clearly identified as to which lot they were found in and must be kept for a minimum of 48 hours.
   8. The technical employees shall complete the log for each lot. The county or State inspectors must sign the log by cutting date and review prior to each phytosanitary certification.
   9. The packing facility must keep available a notebook for recording (separate from the Packing Facility Inspection Log) for any official regulatory visits.
   10. If one live PTwB larva is found during the packing facility cull cutting, the grower lot will be suspended from export to Australia for the remainder of the season.
        
7. Leaf and Stem Tolerance
   1. An average of two whole leaves per box will be the maximum allowable leaf tolerance. For apricots, packed fruit must have no more than an average of 3 stems per box smaller than ½ inch in length and 2 stems larger than ½ inch in length.
       
8. Packing and Storage
   1. All approved lots eligible for shipment to Australia must be segregated from all other fruit at all times.
   2. All approved lots eligible for shipment to Australia must be stored in a properly marked designated area(s).
   3. All boxes must be stamped with the corresponding lot number and pack date.
       
9. Regulatory Inspection: Two percent of the boxes will be randomly selected for inspection and 100 percent of the fruit in the selected boxes will be inspected. Five percent of the fruit in the selected boxes plus any fruit showing signs of possible insect infestation will be cut to look for internal feeders.

   If one live PTwB larva is found at regulatory inspection, the grower lot will be suspended from export to Australia for the remainder of the season.

10. Inspection at Australian port of entry: One interception of a live PTwB larva at Australian port of entry will suspend the grower lot from export to Australia for the remainder of the season.

Sources:

University of California Integrated Pest Management Guidelines for Peach Twig Borer in Stone Fruit. UC IPM Online: http://www.ipm.ucdavis.edu/PMG/r602300611.html

Washington State University Tree Fruit Research and Extension Center: Orchard Pest Management Online