Asiothrixus antidesmae (Takahashi): Whitefly [No Common Name]

California Pest Rating for

Asiothrixus antidesmae (Takahashi): Whitefly [No Common Name]

Hemiptera: Aleyrodidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

In September 2016 the United States Department of Agriculture (USDA) New Pest Advisory Group (NPAG) released a report on Asiothrixus antidesmae that recommended that USDA establish a non-reportable/non-actionable port policy for the whitefly in the continental United States. Stephen Brown requested comments on this proposal.

History & Status:

Background: Asiothrixus antidesmae is a whitefly that feeds by sucking phloem from a variety of plants including: Apocynaceae: Alyxia stellata (maile); Araceae: Alocasia sp. (taro), Anthurium andraeanum (flamingo lily); Calophyllaceae: Calophyllum inophyllum (Alexandrian laurel); Clusiaceae: Garcinia eugenifolia (saptree); Dillenaceae: Dillenia spp.; Lamiaceae: Ocimum spp. (basil); Lecythidaceae: Barringtonia sp.; Phyllanthaceae: Antidesma spp. (chinalaurel); Piperaceae: Piper betel; Rubiaceae: Gardenia jasminoides (cape jasmine), G. taitensis (Tahitian gardenia), Ixora spp., Morinda citrifolia (Indian mulberry); Smilacaceae: Smilax sp. The whitefly can be transported long distances when infested plants or fresh plant parts are moved.

Worldwide Distribution: Asiothrixus antidesmae is native to Taiwan. From there is has spread to Nauru, Palau, Tahiti, Western Samoa, Brunei, the Philippines, Singapore, Sulawesi, Thailand, Guadeloupe, and Saint Lucia. In the United States it has been found in Hawaii, Puerto Rico, and Florida.

Official Control: Asiothrixus antidesmae is not known to be under official control in any other states or nations.

California Distribution: Asiothrixus antidesmae has never been found in the environment of California.

California Interceptions: Asiothrixus antidesmae was intercepted by CDFA 6 times between January 1, 1987 and September 27, 2016 on shipments of fresh plant parts from Hawaii, usually betel leaves (Piper betel).

The risk Asiothrixus antidesmae (whitefly) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: According to the NPAG report Asiothrixus antidesmae is expected to establish a widespread distribution in California. 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: Asiothrixus antidesmae is known to feed on plants in 13 genera in 10 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: Whiteflies are capable of rapid reproduction and can be transported long distances when infested plants or fresh plant parts are moved. Asiothrixus antidesmae 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: Asiothrixus antidesmae is not considered to be an economic pest. It is not expected to lower crop yields. It might increase nursery stock production costs. It is not expected to disrupt markets, change cultural practices, vector other organisms, injure animals, or interfere with water supplies. Asiothrixus antidesmae 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: If Asiothrixus antidesmae were to establish in California it is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. It is not likely to directly affect threatened or endangered species or disrupt critical habitats. It might trigger new chemical treatments in the nursery industry and by residents who find infested ornamental plants unacceptable. A variety of tropical ornamental plantings could be affected by this pest. Asiothrixus antidesmae 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 Asiothrixus antidesmae (Whitefly): 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: Asiothrixus antidesmae 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 (13)

Uncertainty:

There are a wide variety of whiteflies already present in California including some with significantly overlapping host ranges. It is possible that natural enemies of these existing whiteflies and competitive effects will help mitigate any impacts of Asiothrixus antidesmae.

Conclusion and Rating Justification:

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

References:

Smith, J.W. 2016. NPAG Report Asiothrixus antidesmae (Takahashi): Whitefly [no common name]. United States Department of Agriculture New Pest Advisory Group.