Erythrina Twigborer | Pest Rating Proposals and Final Ratings

California Pest Rating for

Terastia meticulosalis Guenée: Erythrina Twigborer

Lepidoptera: Crambidae

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

In October 2015 larvae collected from coral tree plants at a nursery in Oceanside (San Diego County) were confirmed by molecular diagnostics to be Terastia meticulosalis, Erythrina twigborer. A pest rating proposal is required to determine future direction on this pest.

History & Status:

Background: Terastia meticulosalis is a moth that feeds on coral trees (Erythrina spp.). Early instar caterpillars are found inside the stems, leaf stalks, and seed pods¹. Their feeding can cause the tip of the host plant to die back and gradually kill off the upper part of the plant¹. Larvae typically exit the plant to pupate on the ground. The damage attributed to this moth is reported to make the cultivation of Erythrina nearly impossible in Florida³. This moth may be transported long distances when infested plants are moved.

Worldwide Distribution: Terastia meticulosalis is native to Central and South America¹. The moth is known to occur in the southern United States from Florida and South Carolina west to Arizona¹. Populations of Terastia spp. in other areas are presently considered to be different species¹.

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

California Distribution: The only confirmed record of this moth from the environment of California was collected in November 2015 from the Los Angeles County Arboretum. Unofficial records indicate that the moth may be more widespread (see Uncertainty section below).

California Interceptions: Terastia meticulosalis has only been intercepted in two nurseries in San Diego County.

The risk Terastia meticulosalis (Erythrina twigborer) would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Erythrina are commonly grown as ornamentals in southern and coastal California and Terastia meticulosalis is expected to establish wherever suitable hosts are available. It 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: Terastia meticulosalis is only known to feed on coral trees in the genus Erythrina. It receives a Low (1) 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: Terastia meticulosalis is assumed to be capable of rapid reproduction and may be transported long distances when infested plants are moved. The moth 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 Terastia meticulosalis were to become established in California it is not expected to lower any crop yields. It may reduce the value of Erythrina nursery stock and increase production costs of those trees. The moth is not expected to disrupt any markets, change cultural practices, vector other organisms, injure animals, or interfere with water supplies. Terastia meticulosalis 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: Terastia meticulosalis is not expected to lower biodiversity, disrupt natural communities, or change ecosystem practices. It is not likely to directly affect threatened or endangered species or disrupt critical habitats. It may trigger additional treatment programs in the nursery industry and by residents who wish to save their coral trees. Coral trees are grown as ornamentals in southern California and may be extirpated by Terastia meticulosalis. Erythrina twigborer 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 Terastia meticulosalis (Erythrina twigborer): 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: The only official sample of Terastia meticulosalis in California was collected from a site in Los Angeles County. It receives a Low (-1) 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:

Unconfirmed sightings indicate that this moth could be much more widespread in California including Long Beach (September 21, 2015 – Los Angeles County), Mount Washington (October 25, 2015 – Los Angeles County), and Irvine (November 26, 2015 – Orange County)². There have not been any recent formal surveys for this moth in California.

Conclusion and Rating Justification:

Terastia meticulosalis is only known to be established in Los Angeles County. However, if it were to establish a more widespread distribution in the state it is likely to have significant economic and environmental impacts to coral trees in the nursery industry and California landscape. A “B” rating is justified.

References:

¹ Sourakov, Andrei. 2012. Common name: Erythrina moths. University of Florida Featured Creatures. http://entnemdept.ufl.edu/creatures/orn/shrubs/erythrina_moths.htm

² What’s That Bug? http://www.whatsthatbug.com/2015/10/25/erythrina-borer-visits-wtb-offices/

³ Sourakov, Andrei. 2011. Nice partitioning, co-evolution and life histories of Erythrina moths, Terastia meticulosalis and Agathodes designalis (Lepidoptera: Crambidae). Trop. Lepid. Res. 21(2): 84-94. http://troplep.org/TLR/21-2/Sourakov-Niche-partitioning-erythrina-moths-TLR-21-2.pdf

Responsible Party:

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

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