Tag Archives: Diaspididae

Hemiptera, Insects, Mites & Earthworms

Mycetaspis personata (Comstock): Masked Scale

California Pest Rating for
Mycetaspis personata (Comstock):  Masked Scale
Hemiptera: Diaspididae
Pest Rating:  A
PEST RATING PROFILE
Initiating Event:

Mycetaspis personata is commonly intercepted at CDFA’s border stations and presently has a temporary Q-rating.  A pest rating proposal is required to assign a permanent pest rating.

History & Status:

Background:  Mycetaspis personata is a polyphagous armored scale insect that typically feeds on leaves1,2.  It has been considered a pest of citrus in Madeira and mango in Egypt1,2.  Known hosts include:  Anacardiaceae: Anacardium spp.1, mango (Mangifera indica1,2), Mangifera spp.1,2, Tapirira guianensis2; Annonaceae: Annona spp.1,2; Arecaceae: Areca spp.1,2, Chrysalidocarpus lutescens1,2, coconut (Cocos nucifera1,2); Cocos spp.1,2, latan palm (Latania sp.1,2); Phoenix spp.1,2, palmetto (Sabal spp.1,2), walking palm (Socratea exorrhiza)2; Bignoniaceae: Catalpa longisiliqua1,2; Bromeliaceae: Tillandsia spp.1,2; Fabaceae: Bauhinia spp.1,2; Guttiferae: Mammea americana2; Lauraceae: Persea spp.1,2; Malpighiaceae: Banisteria laurifolia1,2; Monimiaceae: Tambourissa spp.1,2; Moraceae: Cuban-laurel (Ficus retusa1,2), weeping fig (Ficus benjamina1,2), Ficus spp.1,2; Musaceae: Musa spp.1,2; Myristicaceae: Virola sebifera2; Myrtaceae: Eugenia spp.1,2, pineapple guava (Feijoa selloviana1,2); Oleaceae: jasmine (Jasminum spp.1,2); Rutaceae: Citrus spp.1,2; Sapotaceae: sapote (Achras sapota1,2); Theaceae: Japanese camellia (Camellia japonica1,2).  Mycetaspis personata may be transported long distances with infested plants or fresh plant parts are moved.

Worldwide Distribution: Mycetaspis personata has a widespread distribution in South America and the Caribbean1,2.  It has spread to several African and Asian nations and is established Mexico, Hawaii, and Florida1,2.

Official Control: Mycetaspis personata is listed as a harmful organism by Japan, the Republic of Korea, and Taiwan3.

California Distribution:  Mycetaspis personata has never been detected in the environment of California.

California Interceptions:  Mycetaspis personata is frequently intercepted by CDFA’s border stations and dog teams on fruit.  It is most often intercepted on mango, but has also been intercepted on other fruit including lime, coconut, and avocado.

The risk Mycetaspis personata (masked scale) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Host plants of Mycetaspis personata are grown throughout California and the scale insect can be expected to establish wherever 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: Mycetaspis personata is polyphagous on a wide variety of plants in at least 18 families.  It receives a High (3) 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: Scale insects are capable of rapid reproduction and can be transported long distances when infested plants or fresh plant parts are moved.  They may also disperse locally by crawling, wind, or by hitchhiking on clothing, equipment, or animals.  Mycetaspis personata receives a High (3) 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: Mycetaspis personata is considered a quarantine pest by several of California’s trading partners.  This insect could disrupt markets for Californian agricultural commodities if it were to establish in the state.  It may also increase crop production costs by triggering additional management practices to ensure that crops are free from the pest.  Mycetaspis personata receives a Medium (2) 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: Mycetaspis personata 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 may trigger additional treatment programs in agriculture and by residents who find infested plants unsightly.  Masked scale may also significantly impact ornamental plantings.  It receives a High (3) 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 Mycetaspis personata (Masked Scale): High (14)

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: Mycetaspis personata 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: High (14)

Uncertainty:  

There have been no recent formal surveys for scale insects in California.  It is possible that mask scale could be established in some localities.

Conclusion and Rating Justification:

Mycetaspis personata has never been found in California and may have significant economic and environmental impacts if it were to establish here. An “A” rating is justified.

References:

1 Miller, Dug, Yair Ben-Dov, Gary Gibson, and Nate Hardy.  ScaleNet.  http://scalenet.info/validname/Mycetaspis/personata/
http://scalenet.info/catalogue/Mycetaspis%20personata/

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

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment: 

Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating:  A

Posted by ls

Hemiptera, Insects, Mites & Earthworms

Thysanofiorinia nephelii (Maskell): Longan Scale

California Pest Rating for
Thysanofiorinia nephelii (Maskell): Longan Scale
Hemiptera: Diaspididae
Pest Rating:  B
PEST RATING PROFILE
Initiating Event:

August 23, 2012 Ron Eng (CDFA) requested a permanent rating for longan scale (Thysanofiorinia nephelii) as follow-up to a find of the Q-rated pest on a longan tree in a nursery in Santa Ana.

History & Status:

Background:  Longan scale is an armored scale insect that is sometimes considered a pest of the tropical fruits longan (Dinocarps longan) and lychee (Litchi chinensis).  In addition to those primary hosts it has also been occasionally recorded on other hosts:  “Kentia sp.” (a palm), “Cassia” (a leguminous tree), Euphorbia longena (a spurge), and Indigofera sp. (a flowering plant) (SEL).  Longan scale may be spread long distances by the movement of infested plants and fruit.

Worldwide Distribution: Longan scale is believed to be native to mainland Asia (India to China) but has invaded Australia, Japan, Taiwan, the Northern Mariana Islands, Brazil, Cuba, Algeria, and Hawaii (sometime before 1932).  It was first detected in Florida, the nation’s leading producer of longan and lychee fruit, in 1996 and considered an emerging pest.  Although it had spread to seven counties by 2007, there were no reports of significant economic damage (Suh et.al. 2007).

Official Control:  Thysanofiorinia nephelii is not known to be under official control in any other states or nations.  The scale was downgraded to non-actionable by USDA in March 2011.

California Distribution:  Longan scale has never been collected in the environment in California.

California Interceptions:  This scale was found in regulatory situations by CDFA 164 times between 1992 and August 2012.  The majority of these were interceptions of crawlers (the 1st instar nymphs) on longan and lychee fruit purchased out of state.  The scale has also been found 5 times on trees in nurseries.

The risk Thysanofiorinia nephelii (longan scale) would pose to California is evaluated below.

Consequences of Introduction: 

1) Climate/Host Interaction: Longan scale has not spread beyond southern Florida since it established there. Longan and lychee are only grown in limited areas of Southern California and the scale would probably be restricted to those areas if it were to enter the state.  Longan scale receives a Low (1) rating for 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: Longan scale feeds primarily on longan and lychee, two tropical sapindaceous fruit trees in two different genera.  However, it has also been reported on four other hosts in three different plant families.  Longan scale receives a Medium (2) for host range.

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: Scale insects have high reproductive rates.  Crawlers of longan scale have been intercepted on longan and lychee fruit many times and may be able to disperse through this pathway.  However, fruit would have to be disposed of in close proximity to a host tree.  Adult female longan scales have been detected on trees in nurseries.  This pathway is how the longan scale is thought to have spread within Florida (Suh et. al. 2007) and is the highest risk pathway for spread within California.  Due to its ability to move long distances through nursery stock longan scale receives a High(3) 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: California has approximately 23 ha of longan and lychee orchards (Crane et. al. 2005) worth an estimated $500,000 annually.  Additionally, there is a market for longan and lychee nursery stock in Southern California.  Furthermore, discussions on internet forums indicate there is interest among residents in growing more longan and lychee fruit in the state.  However, no major economic damage has been reported from the introduction of this scale to Florida’s industry.  Longan scale is not expected to lower yields on these trees but it could increase production costs in some cases by triggering chemical treatment.  It is presumed that the fruits grown in California are produced for domestic consumption so no export issues are considered.  Longan scale is not known to vector any pathogens, injure animals, or interfere with water supplies.  Longan scale receives a Low (1) for economic impact.

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: Longan scale is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  There are no plants listed in California’s threatened and endangered plant list from the genera listed as hosts for the scale (Dinocarps, Litchi, Kentia, Euphorbia, Cassia, or Indigofera).  The scale is not expected to disrupt critical habitats.  Although the scales are often controlled by natural enemies in Florida they do sometimes reach high populations that require additional treatment programs.  The scale is not expected to significantly change cultural practices, home/urban gardening, or ornamental plantings.  Longan scale receives a Medium (2) for environmental impact.

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 Thysanofiorinia nephelii (Longan Scale): Medium(9)

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: Longan scale has never been found in the environment of 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(9)

Uncertainty:

A variety of ants that tend Homoptera, such as longan scale, are abundant in California.  Ants could protect the scales from natural enemies, causing them to reach higher populations more rapidly than in Florida, thereby triggering more chemical treatments.  The market for Asian fruit is expanding in the United States.  Although lychee and longan do not thrive in California at present, changes in technology or the environment could change this in the future.  If lychee and longan production were to expand in California in the future then longan scale may become a more damaging insect.  Furthermore, the possibility exists that longan scale could colonize additional host plants in California.

Longan scale was intercepted in regulatory situations 164 times between 1992 and 2012.  Presumably the scale enters California many additional times and is not intercepted.  Since it has never been found in our environment, it is possible that environmental conditions (such as the lack of humidity) preclude its establishment.  Alternatively, it is possible that the scale is already here and no one has looked for or noticed it.

Conclusion and Rating Justification:

Evidence suggests that the introduction of Longan Scale would be of low economic consequences to California.  Despite the scale’s invasive nature and ability to travel in international and domestic trade of longan and lychee fruit and nursery stock, there is only one scientific paper in the literature that mentions its pest potential.  It has not had major economic consequences since its detection in Florida in 1996.  The pest has a limited host range and would probably not affect the environment of California, with the exception of possible additional treatments by longan and lychee growers.

Evidence also suggests that the introduction of longan scale to California is highly likely to happen.  It has been detected in regulatory situations many times.  It is likely to survive post-harvest treatments and shipment to California.  Due to the small size of crawlers and immobility of adults it is likely to at least occasionally escape detection by inspectors.  It is capable of living on and spreading through nursery stock and is likely to be introduced to favorable environments for establishment through that pathway.

The scale has never been detected in the environment of California.  Additionally, rare fruit markets are expanding and we do have a small commercial longan and lychee fruit industry that may be affected by the pest.  Therefore, it is recommended that the permanent pest rating be set to “B”.

References:

Crane, J.H., Zee, F., Bender, G.S., Faber, B., Brunner, B. and Chia, C.L. 2005. COMMERCIAL

SAPINDACEOUS FRUIT PRODUCTION IN THE USA. Acta Hort. (ISHS) 665:93-104

http://www.actahort.org/books/665/665_11.htm

Suh, S.J., G. S. Hodges, and A. C. Hodges.  2007.  Notes on the Longan Scale, Thysanofiorinia nephelii (Hemiptera: Coccoidea: Diaspididae) in Florida.  Florida Entomologist 90(2): 407-409.  http://journals.fcla.edu/flaent/article/view/75670/73328

SEL:   http://www.sel.barc.usda.gov/catalogs/diaspidi/Thysanofiorinianephelii.htm

Responsible Party:

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

Comment Format:

♦  Comments should refer to the appropriate California Pest Rating Proposal Form subsection(s) being commented on, as shown below.

Example Comment: 

Consequences of Introduction:  1. Climate/Host Interaction: [Your comment that relates to “Climate/Host Interaction” here.]

♦  Posted comments will not be able to be viewed immediately.

♦  Comments may not be posted if they:

Contain inappropriate language which is not germane to the pest rating proposal;

Contains defamatory, false, inaccurate, abusive, obscene, pornographic, sexually oriented, threatening, racially offensive, discriminatory or illegal material;

Violates agency regulations prohibiting sexual harassment or other forms of discrimination;

Violates agency regulations prohibiting workplace violence, including threats.

♦  Comments may be edited prior to posting to ensure they are entirely germane.

♦  Posted comments shall be those which have been approved in content and posted to the website to be viewed, not just submitted.

Pest Rating:  B

Posted by ls

Hemiptera, Insects, Mites & Earthworms

Pseudaulacaspis brimblecombei Williams: Waratah Scale

California Pest Rating for
Pseudaulacaspis brimblecombei Williams: Waratah Scale1
Hemiptera: Diaspididae
Pest Rating:  A
PEST RATING PROFILE
Initiating Event:

Pseudaulacaspis brimblecombei is commonly intercepted by California’s high risk programs and occasionally by dog teams.  This armored scale insect is currently assigned a temporary rating of “Q” and is therefore in need of a permanent pest rating.

 History & Status:

Background:  Pseudaulacaspis brimblecombei is an armored scale insect that typically feeds on the underside of host plant leaves.  It is considered a minor pest of macadamia nut production and ornamental proteas1.  Known hosts include Agavaceae:  cabbage tree (Cordyline australis1), mountain cabbage tree (Cordyline indivisa1); Iridaceae: New Zealand iris (Libertia ixioides1), Libertia sp.1; Proteaceae: Chilean firetree (Embothrium coccineum1), Leucadendron sp.4, Leucospermum sp.4, river lomatia (Lomatia myricoides1), Macadamia sp.1,2, king protea (Protea cynaroides4), oleanderleaf protea (Protea nerifolia1), Protea protea4, Protea sp.4, Gippsland waratah (Telopea oreades1), waratah (Telopea speciosissima1,2), Telopea sp.1; Rutaceae: wharangi (Melicope ternata1); Xanthorrhoeaceae: New Zealand flax (Phormium tenax4).

Worldwide Distribution: Pseudaulacaspis brimblecombei is native to Australia2.  From there it has spread to New Zealand2 and has been found in greenhouses in Europe3.  Interceptions also show that it is present in some plant nurseries and cut flower production sites in Hawaii.

Official Control: Pseudaulacaspis brimblecombei is not known to be under official control in any other states or nations.  However, all species of Pseudaulacaspis are listed as quarantine pests by Japan and the Republic of Korea5.

California Distribution:  Pseudaulacaspis brimblecombei has never been found in the environment of California.

California Interceptions:  Between November 24, 2004 and January 5, 2015 Pseudaulacaspis brimblecombei was intercepted 86 times on shipments of cut flowers and nursery stock from Hawaii.

The risk Pseudaulacaspis brimblecombei (waratah scale) would pose to California is evaluated below.

 Consequences of Introduction: 

1) Climate/Host Interaction: Host plants of Pseudaulacaspis brimblecombei are commonly grown as ornamentals in coastal and southern California. The scale is expected to be able to establish wherever these are grown. Waratah scale receives a Medium (2) 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: Pseudaulacaspis brimblecombei is known to feed on 18 species of plants in 5 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: Scale insects are capable of rapid reproduction and Pseudaulacaspis brimblecombei has demonstrated a propensity to spread long distances on cut flowers and nursery stock.  Crawlers may also spread locally by wind or by hitchhiking on clothing, equipment, or other animals.  Waratah scale receives a High (3) 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: Pseudaulacaspis brimblecombei is considered a minor pest of macadamia nut production and ornamental proteas1.  There are a few commercial growers of macadamia nuts in southern California who may find their yields reduced by this insect.  Proteas are also common in the nursery industry and growers may find their yields reduced as unsightly infested plants may be destroyed.  The establishment of waratah scale in California may also increase crop production costs by both macadamia nut and protea producers.  California producers of cut flowers and nursery stock may experience disruptions in trade as both Japan and Korea consider species of Pseudaulacaspis quarantine pests5.  Waratah scale receives a High (3) 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: Pseudaulacaspis brimblecombei is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  The scale is not expected to directly affect any threatened or endangered species or disrupt any critical habitats.  Waratah scale may trigger new private treatment programs by producers of macadamia nuts and ornamental proteas and by residents who find infested ornamental plants unsightly.  Proteas are common ornamental plants and could be significantly impacted by this insect.  Waratah scale receives a High (3) 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 Pseudaulacaspis brimblecombei (Waratah scale):  High (13)

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: Pseudaulacaspis brimblecombei has never been found in the environment of 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: High (13)

Uncertainty:

Recent surveys for mealybugs on proteas growing in the environment of coastal and southern California would have been likely to detect populations of Pseudaulacaspis brimblecombei but did not find the insect.  Nevertheless, based on the large number of interceptions it is likely that some of the scale insects remained undetected and entered California.  It is possible that some of these scales could have established in limited areas of California.

Conclusion and Rating Justification:

Pseudaulacaspis brimblecombei has never been found in the environment of California and is likely to have significant economic impacts to the nursery, cut flower, and macadamia nut industries in California.  Waratah scale may also have significant environmental impacts by triggering new chemical treatments and damaging ornamental plantings.  An “A” rating is justified.

 References:

1SEL Catalog query results:  http://www.sel.barc.usda.gov/catalogs/diaspidi/Pseudaulacaspisbrimblecombei.htm

2Miller, Dug, Yair Ben-Dov, Gary Gibson, and Nate Hardy.  ScaleNet. http://scalenet.info/validname/Pseudaulacaspis/brimblecombei/

3Malumphy, C. and A.J. Halstead.  2012.  First incursions in Europe of four Australasian species of armoured scale insect (Hemiptera: Diaspididae).  British Journal of Entomology and Natural History 25(4): 193-197.  http://www.cabi.org/isc/abstract/20123419544

4California Department of Food & Agriculture Pest Detection Record Database

5USDA 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:  A

Posted by ls

Hemiptera, Insects, Mites & Earthworms

Pinnaspis uniloba (Kuwana): Unilobed Scale

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

Background:  Pinnaspis 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 japonica1,2.  Pinnaspis 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 Distribution:  Pinnaspis uniloba has never been found in the environment of California.

California Interceptions:  Pinnaspis 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)

Uncertainty:

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.

References:

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

Hemiptera, Insects, Mites & Earthworms

Gymnaspis aechmeae Newstead: Fly Speck Scale

California Pest Rating for
Gymnaspis aechmeae Newstead: Fly Speck Scale
Hemiptera: Diaspididae
Pest Rating: B
PEST RATING PROFILE
Initiating Event:

On October 28, 2013 Dr. Gillian Watson identified fly speck scale, Gymnaspis aechmeae, from a sample of bromeliad plants submitted from a resident’s greenhouse in Orange County (PDR  300P06040190).  Stephen Brown recommended that the scale be run through the draft pest rating process.

History & Status:

Background:  Known colloquially in Australia as “the scourge of the bromeliads, 4” fly speck scale is considered to be a serious pest of the plants1,2,4,5,6.   Known hosts include up to 35 species of Bromeliaceae:  Acanthostachys sp., Acanthostachys strobilacea, Aechmea angustifolia, A. aquilega, A. bracteata7,  Aechmea chantini, A. nidularioides, A. pubescens, Aechmea sp., Ananas comosus, A. sativus, Ananas sp., Aregelia sp., Billbergia nutans, B. leopoldi, B. pyramidalis7, B. saundersii, Billbergia sp, Bromelia serra, B.pinguin2, Bromelia sp., Hogenbergia erythrostachya, H. stellata7,  Hogenbergia sp., Karatas amazonica, Karatas sp., Neoregelia sp., Nidularium princeps, Nidularium sp., Pitcairnia sp., Quesnelia sp., Quesnelia wittmackiana, Tillandsia sp., Vriesea sp., Vriesia platzmanni.  Other occasional hosts include Monstera sp. (Araceae), Asparagus sprengeri (Asparagaceae), Caraguata weilbachii and Chlorophytum sp. (Liliaceae), Villarsia officinalis (Menyanthaceae), and Cymbidium sp. (Orchidaceae)1.  Fly speck scale can be dispersed long distances in the trade of live plants.

Worldwide Distribution: The native range of fly speck scale is uncertain.  It was first discovered on Aechmea aquilegia at Kew Gardens, London, in 18971.  It was found in Spain by 19061, Argentina by 19071, and Florida in 19175.  It has since been found in Brazil, Costa Rica, Puerto Rico, Cuba2, Hawaii, Japan3, Australia4,6, and in many European nations1.  Within the United States it has also been found in additional eastern and southern states (Alabama, District of Columbia, Florida, Louisiana, Maryland, Missouri, New Jersey, New York, Pennsylvania and West Virginia) and Colorado8.

Official Control: Fly speck scale is listed as a quarantine pest in Japan and the Republic of Korea9.

California Distribution:  Fly speck scale has never been found outdoors in California.

California Interceptions:  Fly speck scale was found once in a nursery in San Diego county in 2012 (PDR 1422842).

The risk fly speck scale (Gymnaspis aechmeae) would pose to California is evaluated below.

Consequences of Introduction: 

1)  Climate/Host Interaction: Known outdoor habitats of fly speck scale correspond with tropical, humid environments. The scale is not likely to establish outdoors in California.  However, bromeliads are produced and kept in greenhouses and the scale is likely to establish in these environments.  Fly speck scale receives a Low(1) 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: Fly speck scale is primarily a pest of bromeliads, but it has been found on 41 species in 6 plant families.  The scale 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: Fly speck scale has only 2 generations per year1, but can produce many first instar crawlers (rather than eggs) giving the species high reproductive potential.  The crawlers are able to walk between plants6.  Furthermore, they can be spread long distances when plants are traded, on clothing, or by wind6.  Fly speck scale receives a High(3) 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: Bromeliads are produced in the nursery industry of California.  Fly speck scale is likely to lower the value of this crop by disfiguring the plants with their unsightly presence.  The scale may also increase crop production costs as nurseries are likely to treat infestations or to treat preventively.  Fly speck scale is listed as a quarantine pest by Japan and Korea9 so its presence in California could disrupt trade with those markets.  Fly speck scale may also negatively change normal cultural practices in botanical gardens and nursery greenhouses.  The scale is not expected to lower crop yield, trigger a loss of markets, vector other organisms, affect agriculturally important animals, or affect the water supply.  Fly speck scale receives a High (3) 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 o rganism.
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: The presence of Gymnaspis aechmeae can be expected to trigger regular, preventive private chemical treatment of bromeliads to prevent unsightly plants4 and eradicate known infestations.  Fly speck scale can also be expected to impact cultural practices in home/urban gardening as bromeliad collectors institute quarantine treatments as they acquire new plants4 and discard untreated, infested plants.  The scale is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes.  No hosts of the scale are listed as threatened or endangered species in California and the scale is not expected to affect critical habitats.  Fly speck scale receives a High(3) 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 Fly Speck Scale (Gymnaspis aechmeae):  Medium (12)

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

6)  Post Entry Distribution and Survey Information: Fly speck scale is known only from a single incursion into California in a greenhouse in Orange County in 2013. It has not been found anywhere else since then.  It 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:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: Medium(12)

Uncertainty:

Bromeliad enthusiasts may trade plants frequently and order plants from infested areas via the Internet and mail services; the scale could have a much wider distribution in California.

Conclusion and Rating Justification:

California’s climate is expected to limit the distribution of fly speck scale to greenhouse environments.  There, the introduction of the scale is expected to have a significant economic impact by decreasing the value of contaminated bromeliads and increasing production costs.  Fly speck scale is also expected to have a significant environmental impact as it can be expected to trigger additional private chemical treatments as residents attempt to both eradicate and prevent infestations.  It will also alter cultural practices as residents will quarantine newly acquired plants and dispose of plants that become unsightly.  A “B” rating is justified for Gymnaspis aechmeae.

 References:

1http://www.sel.barc.usda.gov/catalogs/diaspidi/Gymnaspisaechmeae.htm

2Novoa, N.M., G.S. Hodges, M.V. Rubio, P.C. Bonnin, and P.H. Oliver.  2010.  Nuevos registros de insectos escamas (Hemiptera: Sternorrhyncha: Coccoidea) para Cuba.  Fitosanidad 14(3):181-183

3Mito, T. and T. Uesugi.  2004.  Invasive alien species in Japan:  the status quo and the new regulation for prevention of their adverse effects.  Global Environmental Research 8(2): 171-191.  http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CC0QFjAB&url=http%3A%2F%2Fwww.airies.or.jp%2Fattach.php%2F6a6f75726e616c5f30382d32656e67%2Fsave%2F0%2F0%2F08_2-08.pdf&ei=YN9vUtC9IsqDiQLx2IDACg&usg=AFQjCNF_T2F8hHiHRH1hX2i0gqYjsDcT1g&bvm=bv.55123115,d.cGE

4Bromelcairns. 2009 #2 and 2010#3.  Bimonthly Newsletter of Cairns Bromeliad Society, Inc.  P.O. Box 28 Cairns, Queensland, 4870 Australia.  http://www.bromeliadsdownunder.com/wp-content/uploads/2012/03/Bromelcairns-2009-Issue-4.pdf

http://www.bromeliadsdownunder.com/wp-content/uploads/2012/02/Bromelcairns-2010-Issue-3.pdf

5Miller, D.R., G.L. Miller, G.S. Hodges, and J.A. Davidson. 2005.  Introduced scale insects (Hemiptera: Coccoidea) of the United States and their impact on U.S. Agriculture.  Proceedings of the Entomological Society of Washington 107(1): 123-158. http://www.sel.barc.usda.gov/coccoidea/millermihoda2005.pdf

6Illawarra Bromeliad Society Inc. Club News.  October 2012.  92 Brighton Street, Bundeena, NSW 2230  http://www.bromeliad.org.au/news/Ill1012.htm

7Stephens, J.A.  1965.  Some thoughts on bromeliads.  The Bromeliad Society Bulletin.  Vol. XV(5).  http://journal.bsi.org/V15/5/

8 http://www.forestryimages.org/browse/detail.cfm?imgnum=5117097

9 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

Hemiptera, Insects, Mites & Earthworms

Unaspis citri Comstock: Citrus Snow Scale

California Pest Rating for
Unaspis citri Comstock: Citrus Snow Scale
Hemiptera: Diaspididae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:

Unaspis citri is frequently intercepted by CDFA and requires a pest rating proposal to support its pest rating.

History & Status:

Background: Unaspis citri, citrus snow scale, is an armored scale insect that primarily feeds on the trunk and tree limbs of older citrus trees¹. Populations of the scale reduce tree vigor and fruit production¹. Prolonged high populations can cause bark to split, allowing other insect pests and pathogens to invade the tree¹. Known hosts of citrus snow scale include: Anacardiaceae: mango (Mangifera indica³), Mangifera sp.²,³; Annonaceae: custard apple (Annona muricata²,³); Arecaceae: Cocos sp.²,³; Bromeliaceae: Ananas sp.²,³, Spanish moss (Tillandsia usneoides²,³); Celastraceae: evergreen spindle (Euonymus japonicus²,³), broad-leaved spindle tree (Euonymus latifolia²,³), Fabaceae: Acacia sp.²,³, Inga sp.³; Malvaceae: Hibiscus sp.²,³; Musaceae: Musa sp.²,³; Myrtaceae: guava (Psidium guajava²,³); Oleaceae: Osmanthus sp.²,³; Pittosporaceae: Pittosporum sp.²,³; Rosaceae: avocado (Persea americana²,³); Rutaceae: Mediterranean mandarin (Citrus deliciosa²,³), Citrus sp.²,³, key lime (Citrus aurantifolia²,³), bitter orange (Citrus aurantium²,³), Citrus decumana²,³, sweet orange (Citrus sinensis²,³), mandarin (Citrus reticulata²,³), grapefruit (Citrus paradisi²,³), tangerine (Citrus nobilis²,³), citron (Citrus medica²,³), Citrus medica acida², pomelo (Citrus maxima²,³), lemon (Citrus limon²,³), Citrus grandis²,³, kumquats (Fortunella sp.²,³), Glycosmis parviflora²,³, orange jessamine (Murraya paniculata²,³), trifoliate orange (Poncirus sp.²,³), Severina sp.²,³; Sapindaceae: rambutan (Nephelium lappaceum²). Unaspis citri may be transported long distances when infested plants or fresh plant parts are moved.

Worldwide Distribution: Unaspis citri is believed to have originated in Asia, but has spread through many of the citrus growing regions of the world¹.

Official Control: Unaspis citri has listed as a harmful organism by 46 nations including Albania, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Georgia, Germany, Greece, Holy See (Vatican City State), Hungary, India, Ireland, Israel, Italy, Japan, Jordan, Korea, Latvia, Lithuania, Luxembourg, Malta, Monaco, Montenegro, Morocco, Netherlands, New Zealand, Poland, Portugal, Romania, San Marino, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Taiwan, Turkey, United Kingdom, Venezuela4.

California Distribution: Unaspis citri has never been found in the environment of California.

California Interceptions: Unaspis citri is commonly intercepted by CDFA’s border stations on citrus fruit from Mexico and Florida.

The risk Unaspis citri (citrus snow scale) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Citrus is widely planted across much of California and Unaspis citri can be expected to establish wherever it is 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: Unaspis citri is known to feed on 34 varieties of plants in 13 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: Scale insects are capable of rapid reproduction and can be transported long distances when infested plants or fresh plant parts are moved. They may also disperse locally by crawling, wind, or by hitchhiking on clothing, equipment, or animals. Unaspis citri receives a High (3) 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: If Unaspis citri were to establish in California it is expected that it would lower yields and increase crop production costs in citrus nursery stock and fruit industries. Citrus snow scale is also considered a quarantine pest by many of California’s trading partners. The presence of the scale in the state would disrupt markets for fresh fruit and nursery stock. Unaspis citri receives a High (3) 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: Unaspis citri 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 may trigger additional treatment programs in agriculture and by residents who find infested trees unsightly or diminished citrus yields unacceptable. Citrus snow scale may also significantly impact ornamental plantings. It receives a High (3) 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 Unaspis citri (Citrus Snow Scale): High (14)

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: Unaspis citri 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: High (14)

Uncertainty:

Management for other citrus pests may mitigate some of the damage from Unaspis citri.

Conclusion and Rating Justification:

Unaspis citri has never been found in California and it is expected to have significant economic and environmental impacts if it were to enter the state. An “A” rating is justified.

References:

1 Buckley, Courtney R. and Amanda C. Hodges. 2013. University of Florida Featured Creatures: Common Name: citrus snow scale. http://entnemdept.ufl.edu/creatures/orn/scales/citrus_snow_scale.htm

2 Miller, Dug, Yair Ben-Dov, Gary Gibson, and Nate Hardy. ScaleNet. http://scalenet.info/validname/Unaspis/citri/

3 SEL Catalog. http://www.sel.barc.usda.gov/catalogs/diaspidi/Unaspiscitri.htm

4 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:  A

Posted by ls