A Leafhopper | Paraulacizes irrorata (Fabricus) | Pest Rating Proposals and Final Ratings

California Pest Rating for

Paraulacizes irrorata (Fabricius): a leafhopper

Hemiptera: Cicadellidae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

Paraulacizes irrorata is currently Q-rated. A permanent pest rating proposal is required to support an official pest rating.

History & Status:

Background: This is a large (~14 mm in length) leafhopper that is dark with numerous tiny, yellow spots (Overall and Rebek, 2017; Young, 1968). It is reported to feed on a variety of plants, including thistles (Cirsium spp.) (Asteraceae), crape myrtle (Lagerstroemia indica) (Lythraceae), Virginia wildrye (Elymus virginicus) (Poaceae), horseweed (Conyza canadensis) (Asteraceae), prickly lettuce (Lactuca serriola) (Asteraceae), wholeleaf rosinweed (Silphium integrifolium) (Asteraceae), and sorghum (Sorghum sp.) (Poaceae). It is found in vineyards, fruit orchards, and tree nurseries, so it is possible that it feeds on grapevines and trees (Ma et al., 2010; Myers et al., 2007; Overall, 2013). Eggs are laid inside twigs and woody/hardened stems and leaf petioles (Tipping et al., 2006). In a study in North Carolina vineyards, P. irrorata was shown to carry Xylella fastidiosa, the bacteria that causes Pierce’s disease and almond leaf scorch (Myers et al., 2007; Sisterson et al., 2010). However, P. irrorata has not yet been shown to transmit the disease (Overall and Rebek, 2017).

Worldwide Distribution: Paraulacizes irrorata is reported from the central, northeastern, and southeastern United States, Canada (Ontario), and northern Mexico (Maw et al., 2000; Pajero et al., 2008).

Official Control: Paraulacizes irrorata is not known to be under official control anywhere.

California Distribution: Paraulacizes irrorata is not known to occur in California (Symbiota Collections of Arthropods Network).

California Interceptions: Paraulacizes irrorata has been intercepted on plants from Arkansas, West Virginia, Louisiana, and Oklahoma in 1992, 2000, and 2007, in a trailer from Arkansas in 2017, on aircraft from Tennessee in 2000 and 2002, and on a FedEx shipment from Florida in 2017 (California Department of Food and Agriculture).

The risk Paraulacizes irrorata would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: The distribution of Paraulacizes irrorata extends from northern Mexico to Ontario, Canada. This suggests that it could become established over a wide area in California. This leafhopper feeds on a wide variety of plants, and there are likely suitable host plants in much of the state. Therefore, Paraulacizes irrorata receives a High (3) in this category.

– 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: Paraulacizes irrorata has been reported to feed on at least seven genera of plants in three families, but it probably has a much broader host range than this. Therefore, it receives a High (3) in this category.

– 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: Paraulacizes irrorata presumably flies. Therefore, it receives a Medium (2) in this category.

– 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: Paraulacizes irrorata feeds on a broad range of plants. The feeding damage could possibly lower crop yield, but a more serious concern, and a general one for the family Cicadellidae, is the potential for vectoring plant diseases. It is not known if irrorata can vector plant diseases, but it has been confirmed as a carrier of Xylella fastidiosa, the bacteria that causes Pierce’s disease and almond leaf scorch. If it was introduced to California, P. irrorata could potentially vector such pathogens and impact crops, including grapes and almonds. Therefore, it receives a Medium (2) in this category.

Economic Impact: A, E

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.

Economic Impact Score: 2

– 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 Praulacizes irrorata could trigger treatment programs. Therefore, it receives a Medium (2) in this category.

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

Environmental Impact: D

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.

Environmental Impact Score: 2

– 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 Paraulacizes irrorata: Medium (12)**

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: Paraulacizes irrorata is not known to occur in California. It receives a Not established (0) in this category.

–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:

The possible impact of Paraulacizes irrorata is somewhat speculative and it is based on demonstrated examples of impact from other cicadellid species and the possibility of this leafhopper vectoring Pierce’s disease (or other diseases) in crops, including grapes. This leafhopper has not been proven to transmit any plant diseases.

Conclusion and Rating Justification:

Paraulacizes irrorata is a plant-feeding insect that is potentially capable of vectoring plant diseases, including the causative agent of Pierce’s disease, Xylella fastidiosa. There is little evidence that P. irrorata has a significant economic or environmental impact in its current range. However, if it was established in California, this insect would be exposed to a new combination of variables, including new host plants and plant diseases; it is difficult to predict what impacts could result. For these reasons, an “A” rating is justified.

References:

California Department of Food and Agriculture. Pest and damage record database. Accessed April 2, 2018. https://pdr.cdfa.ca.gov/PDR/pdrmainmenu.aspx

Maw, H.E.L., Foottit, R.G., Hamilton, K.G.A., and Scudder, G.G.E. 2000. Checklist of the Hemiptera of Canada and Alaska. National Research Council, Canada. 220 pp.

Myers, A.L., Sutton, T.B., Abad, J.A., and Kennedy, G.G. 2007. Pierce’s disease of grapevines; Identification of the primary vectors in North Carolina. Phytopathology. 97: 1440-1450.

Overall, L.M. 2013. Incidence of Xylella fastidiosa in Oklahoma, survey of potential insect vectors, and identification of potential plant reservoir hosts. Ph.D. Dissertation. Oklahoma State University. 155 pp.

Overall, L.M. and Rebek, E.J. 2017. Insect vectors and current management strategies for diseases caused by Xylella fastidiosa in the southern United States. Journal of Integrated Pest Management. 8: 1-12.

Paiero, S.M., Marshall, S.A., Pratt, P.D., and Buck, M. 2008. The insects of Ojibway Prairie, a southern Ontario tallgrass prairie.

Sisterson, M.S., Thammiraju, S.R., Lynn-Patterson, K., Groves, R.L., and Daane, K.M. 2010. Epidemiology of diseases caused by Xylella fastidiosa in California: Evaluation of alfalfa as a source of vectors and inocula. Plant Disease. 94: 827-834.

Symbiota Collections of Arthropods Network. Accessed March 2, 2018. http://scan1.acis.ufl.edu

Tipping, C., Triapitsyn, S.V., and Mizell III, R.F. 2006. First record of an egg parasitoid for the North American proconiine sharpshooter Paraulacacizes irrorata (Hemiptera: Cicadellidae), with notes on rearing techniques. Florida Entomologist. 89(2): 288-289.

Young, D.A. 1968. Taxonomic study of the Cicadellinae (Homoptera: Cicadellidae); Part 1: Proconiini. United States National Museum Bulletin. 261. 287 pp.

Author:

Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741; plant.health[@]cdfa.ca.gov.

Responsible Party:

Jason Leathers, 2800 Gateway Oaks, Sacramento CA 95833, (916) 654-1211, plant.health[@]cdfa.ca.gov

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4/30/18 – 6/14/18

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