The Future of San Jose Scale (SJS) Management


San Jose scale, Quadraspidiotus perniciosus (Comstock), or SJS, is a widespread pest of tree fruit as well as tree nut, berry, and other ornamental and woody hosts across the United States.  San Jose scale females are immobile, but release a sex pheromone to attract males for mating.  Female scales can produce several hundred live offspring, known as crawlers, that disperse and feed on limbs and fruit.  Feeding by large populations of scales can cause loss of tree vigor, injury to the surface and underlying tissues of fruit, and potentially limb or tree death under severe situations. 


Adult male San Jose scale can be monitored using the PHEROCON®  SJS lure and the PHEROCON V SJS trap.  Additionally, San Jose scale crawler abundance can be assessed by wrapping a piece of black electrical tape tightly around a tree limb (typically in areas of known infestations) and then wrapping a piece of double-sided sticky tape over top of the electrical tape. 


Recently, research has been initiated by Trécé to develop a novel product for disruption of San Jose scale mating.  The technology behind this experimental product is the same as with the various moth pests like codling moth, oriental fruit moth, or navel orangeworm – saturating an area with high doses of synthetic sex pheromones so that males are unable to find females for mating.  Trials conducted by university researchers in Georgia and Michigan using Trécé’s experimental SJS mating disruption have shown very promising results by greatly reducing captures of adult males and crawlers in orchard crops.  Trécé will continue to enhance this product and commercialize it in the near future.

More information regarding PHEROCON monitoring and CIDETRAK® mating disruption may be seen on Trécé’s website or under IPM PARTNER® Guidelines for Use.

Trécé experimental mating disruption dispenser for SJS (Source: Brett Blaauw, University of Georgia)

SJS damage on apple (Source: Brent Short, Trécé Inc.)

Adult male SJS (Source: Brett Blaauw, University of Georgia)

PHEROCON V trap and SJS lure (Source: Ashley Lovelady, Trécé Inc.)

Tape wrapped around tree limb for monitoring SJS crawlers (Source: Brent Short, Trécé Inc.)

SJS crawlers (Source: University of California IPM)

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