Tag Archives: Unilobed Scale

Pinnaspis uniloba (Kuwana): Unilobed Scale

California Pest Rating for
Pinnaspis uniloba (Kuwana): Unilobed Scale
Hemiptera: Diaspididae
Pest Rating:  B

Initiating Event:

Pinnaspis uniloba is occasionally intercepted by CDFA and presently has a temporary rating of “Q”.  A pest rating proposal is required to assign a permanent pest rating.

History & Status:

BackgroundPinnaspis uniloba is an armored scale insect that feeds on a variety of plants.  Known hosts include: Apocynaceae: Alyxia sp1,2, maile (Alyxia olivaeformis1,2); Fabaceae: Bauhinia racemosa1,2; Magnoliaceae: Michelia sp.1,2; Oleaceae: Osmanthus sp.1,2, sweet olive (Osmanthus fragrans1,2), fortune’s tea olive (Osmanthus fortunei1,2); Rutaceae: bael fruit (Aegle marmelos1,2); Theaceae: Adinandra sp.1,2, Adinandra milletti1,2, Adinandra ryukyuensis2, Japanese camellia (Camellia japonica1,2), Cleyera japonica1,2, Cleyera ochnacea1,2, Eurya japonica1,2, Thea japonica1,2Pinnaspis uniloba may be transported long distances when infested plants or fresh plant parts are moved.

Worldwide Distribution: Pinnaspis uniloba is probably native to Asia.  It has been reported in China1,2, India1,2, Japan1,2, and South Korea2.  From there it has spread to the Hawaiian Islands.

Official Control: Pinnaspis uniloba is not known to be under official control in any other states or nations3.

California DistributionPinnaspis uniloba has never been found in the environment of California.

California InterceptionsPinnaspis uniloba has been intercepted 92 times on plants and fresh plant material from Hawaii.  Many of these interceptions have occurred on Maile (Alyxia sp.) leaf leis.

The risk Pinnaspis uniloba (unilobed scale) would pose to California is evaluated below.

Consequences of Introduction: 

Climate/Host Interaction: A few of the host plants of Pinnaspis uniloba are widely grown as ornamentals in California and the scale may be expected to establish everywhere they are grown. It receives a High (3) in this category.

Evaluate if the pest would have suitable hosts and climate to establish in California.  Score:

– Low (1) Not likely to establish in California; or likely to establish in very limited areas.
– Medium (2) may be able to establish in a larger but limited part of California.
– High (3) likely to establish a widespread distribution in California.

2)  Known Pest Host Range: Pinnaspis uniloba is known to feed on 16 species of plants in six families.  It receives a Medium (2) in this category.

Evaluate the host range of the pest. Score:

– Low (1) has a very limited host range.
– Medium (2) has a moderate host range.
– High (3) has a wide host range.

3)  Pest Dispersal Potential: Pinnaspis uniloba has only one generation per year.  Armored scales may be transported long distances when infested plants are moved and may be dispersed locally by crawling, wind, or by hitchhiking on clothing, equipment, or animals.  Pinnaspis uniloba receives a Medium (2) in this category.

Evaluate the natural and artificial dispersal potential of the pest. Score:

– Low (1) does not have high reproductive or dispersal potential.
– Medium (2) has either high reproductive or dispersal potential.
– High (3) has both high reproduction and dispersal potential.

4)  Economic Impact: Pinnaspis uniloba is not expected to lower any crop yields.  It may reduce the value of some nursery stock by disfiguring plants with its presence.  It is not expected to disrupt markets, change cultural practices, vector other organisms, injure animals, or interfere with water supplies.  Pinnaspis uniloba receives a Low (1) in this category.

Evaluate the economic impact of the pest to California using the criteria below. Score:

A. The pest could lower crop yield.
B. The pest could lower crop value (includes increasing crop production costs).
C. The pest could trigger the loss of markets (includes quarantines).
D. The pest could negatively change normal cultural practices.
E. The pest can vector, or is vectored, by another pestiferous organism.
F. The organism is injurious or poisonous to agriculturally important animals.
G. The organism can interfere with the delivery or supply of water for agricultural uses.

– Low (1) causes 0 or 1 of these impacts.
– Medium (2) causes 2 of these impacts.
– High (3) causes 3 or more of these impacts.

5)  Environmental Impact: Pinnaspis uniloba is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  It is not expected to directly affect threatened or endangered species or disrupt critical habitats.  It might trigger chemical treatments in the nursery industry and by residents who find infested ornamentals unsightly.  It is not expected to significantly impact cultural practices, home/urban gardening, or ornamental plantings.  Pinnaspis uniloba receives a Medium (2) in this category.

Evaluate the environmental impact of the pest on California using the criteria below.

A. The pest could have a significant environmental impact such as lowering biodiversity, disrupting natural communities, or changing ecosystem processes.
B. The pest could directly affect threatened or endangered species.
C. The pest could impact threatened or endangered species by disrupting critical habitats.
D. The pest could trigger additional official or private treatment programs.
E. The pest significantly impacts cultural practices, home/urban gardening or ornamental plantings.

Score the pest for Environmental Impact. Score:

– Low (1) causes none of the above to occur.
– Medium (2) causes one of the above to occur.
– High (3) causes two or more of the above to occur.

Consequences of Introduction to California for Pinnaspis uniloba (Unilobed Scale):  Medium (10)

Add up the total score and include it here.

– Low = 5-8 points
– Medium = 9-12 points
– High = 13-15 points

6)  Post Entry Distribution and Survey Information: Pinnaspis uniloba has never been found in California and receives a Not established (0) in this category.

Evaluate the known distribution in California. Only official records identified by a taxonomic expert and supported by voucher specimens deposited in natural history collections should be considered. Pest incursions that have been eradicated, are under eradication, or have been delimited with no further detections should not be included.

– Not established (0) Pest never detected in California, or known only from incursions.
– Low (-1) Pest has a localized distribution in California, or is established in one suitable climate/host area (region).
– Medium (-2) Pest is widespread in California but not fully established in the endangered area, or pest established in two contiguous suitable climate/host areas.
– High (-3) Pest has fully established in the endangered area, or pest is reported in more than two contiguous or non-contiguous suitable climate/host areas.

Final Score:

The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium (10)


Pinnaspis uniloba is currently not known to be present anywhere in North or South America.  It is possible that some states or nations could impose new trade restrictions if it were to become abundant in California.

Conclusion and Rating Justification:

Pinnaspis uniloba has never been found in California.  It is expected to have limited impacts if it were to enter the state.  The scale is most often intercepted on leis and, because of its limited host range, is unlikely to encounter suitable host material when it enters the state via this pathway.  A “B” rating is justified.


1 Miller, Dug, Yair Ben-Dov, Gary Gibson, and Nate Hardy.  ScaleNet.  http://scalenet.info/validname/Pinnaspis/uniloba/

2 SEL Catalog.  http://www.sel.barc.usda.gov/catalogs/diaspidi/Pinnaspisuniloba.htm

3 USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD).  https://pcit.aphis.usda.gov/pcit/

Responsible Party:

Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.

Pest Rating:  B

Posted by ls