Kallitaxila granulata (Stål): A Planthopper

California Pest Rating for

Kallitaxila granulata (Stål): A Planthopper

Hemiptera: Tropiduchidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

The planthopper Kallitaxila granulata is frequently intercepted by CDFA on shipments of plant products from Hawaii. This organism is presently assigned a temporary rating of “Q”. A pest rating proposal is needed to determine future actions on this pest.

History & Status:

Background: Kallitaxila granulata is a moderately polyphagous planthopper that feeds on at least 24 species of plants in at least 19 families. Adults lay eggs singly or in clusters along leaf veins, typically on the underside of leaves². Nymphs and adults both feed on leaves. Known hosts include: Apocynaceae: Plumeria acuminata (plumeria)²; Asparagaceae: Cordyline fruicosa (ti)²; Asteraceae: Wedelia sp.³; Caprifoliaceae: Lonicera sp. (honeysuckle)³; Cibotiaceae: Cibotium chamissoi (hapuu)²; Convovulaceae: Ipomoea triloba (Aiea morning glory)³; Euphorbiaceae: Aleurites moluccana (kukui)², Euphorbia heterophylla³; Fabaceae: Erythrina sandwicensis (wiliwili)³; Erythrina variegata (India coral bean)², Lablab purpureus (lablab beans)³; Gleicheniaceae: Dicranopteris linearis (uluhe)²; Lamiaceae: Vitex sp.³; Malvaceae: Thespesia populnea (milo tree)³; Moraceae: Ficus benjamina (weeping fig)³; Myrtaceae: Metrosideros polymorpha (ohia-lihua)²; Psidium guava (guava)²; Polygonaceae: Coccoloba uvifera (sea grape)³; Rubiaceae: Coffea sp. (coffee)³; Rutaceae: Citrus paradisi (grapefruit)², Citrus sp.³; Scrophulariaceae: Myoporum acuminatum³; Thymelaeaceae: Wikstroemia sp. (akia)³; Verbenaceae: Lantana montevidensis³, . The planthopper has the potential to spread long distances through commerce in infested plants and plant products.

Worldwide Distribution: Kallitaxila granulata is native to the Philippines. From there it spread to Christmas Island, the Cook Islands, Vietnam, China, and Hawaii⁴.

Official Control: Kallitaxila granulata is not known to be under official control in any states or nations.

California Distribution: Kallitaxila granulata has never been found in the environment of California.

California Interceptions: Kallitaxila granulata is frequently intercepted on shipments of plant products from Hawaii including basil, betel, curry, ginger, malangai, orchids, and ti¹.

The risk Kallitaxila granulata (a planthopper) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Some of the known hosts of Kallitaxila granulata are widely grown as ornamentals (e.g., Ficus benjamina) and crops (e.g., citrus) in California. The planthopper is likely to establish wherever hosts are grown. The insect 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: Kallitaxila granulata is known to feed on at least 24 species of plants in 19 plant families. The host list for Kallitaxila granulata expanded greatly with its introduction to Hawaii. It is likely that the plant hopper would continue to colonize new plants if it established in California. This is likely to cause additional economic and/or environmental impacts that are not considered in this document. The planthopper 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: Planthoppers have high reproductive potential and may spread long distances through the movement of infested plants or plant products. Kallitaxila granulata 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: Kallitaxila granulata is not expected to lower crop yields. Because the planthopper has a limited distribution, its entry into California may disrupt some markets as it is likely to contaminate commodities with its presence. The planthopper may increase crop production costs, especially in the nursery industry, as growers treat to ensure clean plants. Kallitaxila granulata is not expected to negatively change cultural practices, vector pestiferous organisms, injure animals, or interfere with water supplies. The planthopper 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: Kallitaxila granulata is not expected to lower biodiversity, disrupt natural communities, or change ecosystem processes. No plants listed as threatened or endangered species in California are expected to be hosts for the plant hopper, nor is the plant hopper expected to disrupt critical habitats. The leaf hopper may trigger additional private treatment programs within the nursery industry as some growers may treat in order to maintain nursery stock cleanliness. The leaf hopper is not expected to impact cultural practices, home/urban gardening, or ornamental plantings. Kallitaxila granulata 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 Kallitaxila granulata: 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: Kallitaxila granulata has not 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:

Kallitaxila granulata is frequently intercepted on shipments of plant products from Hawaii. Presumably, it has also been present on other shipments that were not intercepted and have entered the state. There have not been any formal surveys of California for this plant hopper. Therefore, it is likely that Kallitaxila granulata is either already present in parts of the state or that environmental conditions here are not conducive to establishment. The places where the planthopper is known to be established have humid tropical environments. The Mediterranean climate of California may not be suitable for the plant hopper.

Conclusion and Rating Justification:

Kallitaxila granulata has not yet been documented to cause significant economic or environmental impacts anywhere it has established. If the plant hopper were to enter California, economic impacts are expected to be limited to possible disruptions to host plant markets when the insect is found. Furthermore, production costs may increase in the nursery industry as new treatments could be triggered in order to maintain plant cleanliness. Environmental impacts are expected to be limited to these possible new chemical treatments. However, the plant hopper greatly expanded its host range when it was introduced to Hawaii. It is likely to continue to colonize new hosts in California. Due to potential economic and environmental impacts of the entry of Kallitaxila granulata into California, an “A”-rating is justified.

References:

¹Von Ellenrieder, Natalia. 2007. A planthopper (Kallitaxila granulata). California Plant Pest & Disease Report 23(1): 19. http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0CCsQFjAC&url=http%3A%2F%2Fwww.cdfa.ca.gov%2Fplant%2FPPD%2FPDF%2Fkallitaxila_granulata.pdf&ei=kTe8U_3KDojPiwLM-IGACQ&usg=AFQjCNH2ilXv8591Cqo7A2UW721tVhR6fg&bvm=bv.70138588,d.cGE

²Yang, Pingjun, Andrei Alyokhn, and Russell Messing. 2001. Patterns of oviposition and parasitism of eggs of Kallitaxila granulata (Homoptera: Tropiduchidae), a newly invasive planthopper in Hawaii. Proc. Hawaiian Entomological Society 35: 77-83. http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/8104/9Yang.pdf?sequence=1

³Asche, Manfred. 2000. New state records of immigrant planthoppers in Hawaii (Homoptera: Fulgoroidea). Proc. Hawaiian Entomological Society 34: 185-187. http://scholarspace.manoa.hawaii.edu/bitstream/handle/10125/8409/Note2.pdf?sequence=1

⁴FLOW Hemiptera Database: http://hemiptera-databases.org/flow/?page=explorer&db=flow&lang=en&card=taxon&rank=species&id=9580