Spotted Lanternfly | Pest Rating Proposals and Final Ratings

California Pest Rating for

Lycorma delicatula White: Spotted Lanternfly

Hemiptera: Fulgoridae

Pest Rating: A

PEST RATING PROFILE

Initiating Event:

On October 30, 2014 Duane Schnabel distributed information from the National Plant Board that Lycorma delicatula has been found in four counties in Pennsylvania and may have been distributed to other states. A pest rating proposal is needed to determine future direction on this pest.

History & Status:

Background: Lycorma delicatula is a fulgorid hopper that is known to feed on at least 41 species of trees and herbs^1. The spotted lanternfly has one generation per year and overwinters as eggs in an ootheca¹. In Korea, eggs hatch in mid-May and nymphs begin sucking saps from young stems and leaves¹. Nymphs do not fly and are particularly polyphagous, feeding on almost any plant they encounter. Their feeding produces large quantities of fluid, which covers stems and leaves¹. Infestations can weaken plants and eventually kill them¹. Adult spotted lanternfly can fly but tends to spread by walking. By September, many of the adults have moved to preferred hosts, if they are available¹. The strongly preferred host for adult feeding is tree of heaven (Ailanthus altissima) but they also prefer bee bee tree (Tetradium (=Evodia) daniellii) and Amur cork tree (Phellodendron amurense)¹. The insect will also feed on a wide variety of other plants including grapes (Vitis spp.) and stone fruit (Prunus spp.). Oothecae are typically deposited on trees with a smooth surface structure¹. The most likely pathway for long-distance spread of Lycorma delicatula is the movement of oothecae on infested nursery stock or possibly other objects.

Partial Host List: Betulaceae: Betula platyphylla¹ (Japanese white birch); Cornaceae: Cornus controversa¹ (wedding cake tree), C. kousa¹ (kousa dogwood), C. officinalis¹ (Japanese cornel); Elaeagnaceae: Elaeagnus umbellata¹ (Japanese silverberry); Juglandaceae: Juglans mandshurica¹ (Manchurian walnut); Meliaceae: Cedrela fissilis¹, Toona sinensis¹ (Chinese mahogany); Oleaceae: Syringa vulgaris¹ (lilac); Pinaceae: Pinus densiflora¹ (Japanese red pine); P. strobus¹ (eastern white pine); Rosaceae: Prunus serrulata¹ (Japanese cherry), P. yedoensis¹ (yoshino cherry); Rutaceae: Phellodendron amurense¹ (Amur cork tree), Tetradium daniellii¹ (bee bee tree); Salicaceae: Populus alba¹ (white poplar); Sapindaceae: Acer palmatum¹ (Japanese maple), Acer saccharinum¹ (silver maple); Simaroubaceae: Ailanthus altissima¹ (tree of heaven), Picrasma quassioides¹ (bitterwood); Ulmaceae: Zelkova serrata¹ (keyaki); Vitaceae: Parthenocissus quinquefolia¹ (Virginia creeper), Vitis amurensis¹ (Amur grape), Vitis vinifera¹ (grape vine).

Worldwide Distribution: Lycorma delicatula is native to the southern part of China and other subtropical regions of southeast Asia¹. It was not known to be invasive until it spread to Korea in 2006 and to Pennsylvania in 2014.

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

California Distribution: Lycorma delicatula has not been found in California.

California Interceptions: Lycorma delicatula has not been intercepted in California.

The risk Lycorma delicatula (spotted lanternfly) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Host plants are commonly grown in California and spotted lanternfly is likely to establish wherever they are found. Lycorma delicatula 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: Lycorma delicatula feeds on at least 41 species of plants in at least 14 families. These include multiple agriculturally important crops and common ornamentals in California. 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: Lycorma delicatula has only one generation per year and tends to move by walking but oothecae may be dispersed long distances by the movement of infested nursery stock or other items. Spotted lanternfly 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: Infestations of Lycorma delicatula may lower crop yields and increase production costs in economically important crops such as grape, stone fruit, and nursery stock. Since it entered Korea, the insect has caused considerable damage in vineyards. Although it is not yet under official control in any states or nations, the presence of this pest in agricultural commodities may cause trade disruptions due to its limited range in North America. Spotted lanternfly is not expected to change normal cultural practices, vector other organisms, or interfere with water supplies. Lycorma delicatula 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: Spotted lanternfly is not expected to lower biodiversity, disrupt natural communities or change ecosystem processes. It is not expected to directly affect endangered species or disrupt critical habitats. It may trigger new treatments in vineyards and stone fruit orchards and by residents who find infested plants unsightly. Spotted lanternfly may also significantly affect home/urban gardening by feeding on grapes and trees. Lycorma delicatula 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 Lycorma delicatula (Spotted Lanternfly): 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: Lycorma delicatula has not 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 formal surveys for Lycorma delicatula in California. It may already be present in some localities.

Conclusion and Rating Justification:

Spotted lanternfly (Lycorma delicatula) has never been found in California and is likely to have significant economic and environmental impacts. An A-rating is justified.

References:

¹Kim, Jae Geun, Eun-Hyuk Lee, Yeo-Min Seo, and Na-Yeon Kim. Cyclic Behavior of Lycorma delicatula (Insecta: Hemiptera: Fulgoridae) on Host Plants. J Insect Behav (2011) 24: 423-435. http://ag.udel.edu/delpha/7969.pdf