On-tree sequential field sampling protocol

Any person competent to recognize codling moth (CM) damage can do the sampling. However, those without a pesticide consultants' license (or commercial applicator's license) must participate in a pre-season training session.

The field sampling for export to Taiwan must be done within 14 days of harvest. Begin on-tree samples in the area of highest CM pressure. Trees should be randomly selected, but separated by roughly 70 feet. Examine 60 half-fruits per tree for CM entries. A half-fruit is a fruit of which an entire half plus the calyx can be seen. Begin at the top of the tree and work down until a total of 60 fruits have been examined. The number of trees sampled will depend on the amount of CM injury that is found. A clean orchard block may require sampling as few as 21 trees to complete the evaluation. Record only the successful CM entries as injury in the Taiwan CM field sampling form.This form must accompany the delivery of fruit or be on file in the packing facility for each grower lot to be exported to Taiwan. If 0.2% or more of the fruit in the sample have live larvae present, the orchard is prohibited for export to Taiwan.

If, following a 50 tree sample, no decision can be made to reject or accept the orchard block (detection of 4 to 7 live larvae after 50 trees), the field sample can be repeated no sooner than 7 days from the date of the original sample. Alternatively, the second sample in such blocks may be the bin sample.

Bin Sampling Alternative

A minimum of 1500 fruit must be inspected per grower lot to look for larvae and insect damage. It is recommended to randomly sample no more than 25 fruit per bin (not from the top layer). If the lot size is smaller than 60 bins more fruit can be sampled from each bin. Bins sampled should represent fruit from all parts of the orchard (lot). All suspect fruit and a minimum of 150 fruit must be cut. If more than 0.15% of the fruit in the sample have live larvae present (2 live larvae in 1500 fruit), the orchard is prohibited for export to Taiwan.

For more information and directions visit this training web page: http://entomology.tfrec.wsu.edu/Cullage_Site/CMtraining.html

More Links

WSU-TFREC – Instructions for orchard visual fruit sampling & field bin sampling Taiwan Orchard Sampling Worksheet (pdf) Taiwan Bin Sampling Form (pdf)