Coleophoma empetri (Rostr,) Petr. 1929

California Pest Rating for

Coleophoma empetri (Rostr,) Petr. 1929

Pest Rating: B

PEST RATING PROFILE

Initiating Event:

On April 27, 2016 a mail shipment containing cut foliage of Galax sp. was intercepted by the Santa Barbara County Dog Team, at the FedEx Service Center in Goleta, Santa Barbara County. The shipment had originated in Florida and was destined to a nursery in Carpinteria, Santa Barbara County. Samples of diseased leaves exhibiting leaf spots were collected by the County and sent to the CDFA Plant Pathology Laboratory for disease diagnosis. On April 29, 2016 Suzanne Latham, CDFA plant pathologist, identified the fungal pathogen, Coleophoma empetri, as the cause for the disease. The pathogen has not been previously reported in California and therefore, was assigned a temporary Q rating. Subsequent action taken by the County resulted in the destruction of the intercepted shipment of Galax sp. foliage (CDFA, 2016). The risk of infestation of Coleophoma empetri in California is evaluated and a permanent rating is herein proposed.

History & Status:

Background: Originally described as Septoria empetri, the fungal pathogen Coleophoma empetri is also known by other synonyms, Rhabdostromina empetri, Sporonema oxycocci, and Coleophoma rhododendri, and Coleophoma ericae. The pathogen is widely distributed and found on living and dead leaves and fruit of many different plant species (Farr & Rossman, 2016; Sutton, 1980).

Disease cycle: There is a paucity of specific information on Coleophoma empetri. However, it is likely that the development of disease caused by the pathogen would be similar to other pycnidia-forming fungal pathogens. The pathogen overwinters as mycelium or immature pycnidia in infected fruit and diseased plant debris. Under high moisture and cool temperature conditions, pycnidia swell and release conidia which are spread by splashing rain, irrigation, water, and so on. Seed transmission is not known for C. empetri. Infection of host plants and severity of disease development is likely to require high moisture and cool temperatures. In the development of fruit rot of berries, conidia initiate infection during bloom and early berry development. As infected fruit mature, hyphae continue to invade the fruit and rot symptoms do not develop until the late growing season and mostly in storage (Kusek, 1995).

Dispersal and spread: Splashing rain and irrigation water, air currents, infected plants, infected plant debris, cultivation tools, animals, and contaminated clothing.

Hosts: Archontophoenix alexandrae (Alexander palm), Arctostaphylos sp. (Manzanita), A. uva-ursi, Arctous alpine (bearberries), Betula sp. (birch), Camellia sp., Cajanus cajan (pigeon pea), Canavalia ensiformis (Jack bean), Capsicum annuum (bell peppers), Croton sp., Diapensia sp., D. obovata (pincushion plant), Elaeagnus sp. (oleaster), E. macrophylla, Empetrum sp., E. nigrum (black browberry), Erica carnea (winter heath), Eucalyptus sp. E. tereticornis (forest red gum), Ficus sp., Fraxinus sp. (ash), Galax aphylla (beetleweed/coltsfoot), Gaultheria shallon (shallon), Gaylussacia brachycera (box huckleberry), Juniperus sp. (juniper), Kalmia angustifolia (sheep laurel), Laurus sp., L. nobilis (sweet bay), Leucothoe sp., Loiseleuria sp., L. procumbens, Lonicera sp. (honeysuckle), L. periclymenum, Malus sylvestris (European crab apple), Paxistima canbyi (Canby’s mountain-lover), Plea europaea, Prunus laruocerasus (cherry laurel), P. ponticum, Rhododendron sp., R. maximum, Solanum tuberosum (potato), Stransvaesia sp., Taxus baccata (English yew), Vaccinium sp. (blueberry), V. macrocarpon (American cranberry), V. ovatum (California huckleberry), V. oxycoccos (bog cranberry), V. vitis-idaea (lingonberry) (Farr & Rossman, 2016; Kusek, 1995; Sutton, 1980).

Symptoms: Coleophoma empetri causes leaf spot, fruit rot and tuber skin spot disease on numerous hosts in numerous families. Symptoms of ripe rot on cranberry fruit initially appear as a small soft area which expands over the entire fruit. Diseased fruit appear off-red or reddish orange, and internally watery, squirting a watery fluid when squeezed. However, as not all watery-soft fruit is caused by the pathogen, the latter must be isolated from the diseased fruit to confirm an association with the symptoms (Kusek, 1995).

Disease Potential: Specific information on quantitative crop losses caused by Coleophoma empetri has not been reported. Photosynthetic area can be reduced due to leaf spotting. In severe infections, leaf wilt and drop may be expected. Symptomatic host plants infected with the pathogen may be more of a serious problem for nursery greenhouse productions where favorable wet requirements for disease development and spread are more likely to occur under controlled environments than in open field environments in California. The disease could negatively impact value and marketability of nursery-grown plants including ornamental and landscape plants such as Manzanita, Camellia, Rhododendron, and Eucalyptus. The pathogen causes fruit rot that is apparent during late growing season and mainly in storage.

Worldwide Distribution: Coleophoma empetri is globally widely distributed. Asia: India, USSR; Europe: Finland, Lithuania, Poland, USSR, United Kingdom, Ukraine, Scotland, Germany; North America: Alaska, Maryland, Massachusetts, Maine, Michigan, New Jersey, Oregon, Tennessee, Virginia, Washington, Wisconsin, and Northwestern states (Farr & Rossman, 2016).

Official Control: Currently, has a temporary Q rating in California.

California Distribution: is not established in California.

California Interceptions: A single shipment of Coleophoma empetri-infected Galax sp. foliage was intercepted on April 27, 2016 at the FedEx Service Center in Goleta, Santa Barbara County (see ‘Initiating Event’).

The risk Coleophoma empetri would pose to California is evaluated below.

Consequences of Introduction:

1) Climate/Host Interaction: Evaluate if the pest would have suitable hosts and climate to establish in California:

Score: 2

– 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.

Risk is Medium (2): Coleophoma empetri may be able to establish on suitable host plants growing in high moisture and cool to warm climate conditions. These conditions would likely limit natural establishment to northern coastal regions of California.

2) Known Pest Host Range: Evaluate the host range of the pest:

Score: 2

– Low (1) has a very limited host range.

– Medium (2) has a moderate host range.

– High (3) has a wide host range.

Risk is Medium (2): Coleophoma empetri has a moderate host range that includes many host species in different plant families. Most hosts grow under cool and wet climates. In California, main hosts include ornamental, landscape, and fruit berry plants such as, Manzanita, Camellia, Rhododendron, Eucalyptus, blueberry, and cranberry.

3) Pest Dispersal Potential: Evaluate the natural and artificial dispersal potential of the pest:

Score: 2

– 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.

Risk is High (2): Coleophoma empetri has high reproduction and dispersal potential. The pathogen can be spread over short and long distance by splashing rain and irrigation water, air currents, infected plants, infected plant debris, cultivation tools, animals, and contaminated clothing.

4) Economic Impact: Evaluate the economic impact of the pest to California using the criteria below:

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.

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.

Risk is Medium (2): The pathogen may be more of a serious problem for nursery greenhouse productions where favorable wet requirements for disease development and spread are more likely to occur under controlled environments than in open field environments in California. The disease could negatively impact value and marketability of nursery-grown plants including ornamental and landscape plants. Also, the pathogen may cause fruit rot that is apparent during late growing season and mainly in storage.

5) Environmental Impact: 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: 3

– 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.

Risk is High (3): Severe infections caused of Coleophoma empetri could impact ornamental plantings. Under suitable conditions that result in severe disease, threatened or endangered plant species, namely, manzanita (Arctostaphylos spp.) could be affected and disrupt critical habitats.

Consequences of Introduction to California for Coleophoma empetri:

Add up the total score and include it here:

-Low = 5-8 points

–Medium = 9-12 points

-High = 13-15 points

Total points obtained on evaluation of consequences of introduction to California = 11 (Medium).

6) Post Entry Distribution and Survey Information: 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:

Score: 0

–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.

Evaluation is Not Established (0). Coleophoma empetri is not established in California.

Final Score:

7) The final score is the consequences of introduction score minus the post entry distribution and survey information score: (Score)

Final Score: Score of Consequences of Introduction – Score of Post Entry Distribution and Survey Information = 11 (Medium).

Uncertainty:

None.

Conclusion and Rating Justification:

Based on the evidence provided above the proposed rating for Coleophoma empetri is B.

References:

Agrios, G. N. 2005. Plant Pathology (Fifth Edition). Elsevier Academic Press, USA. 922 p.

CDFA. 2016. Santa Barbara County Dog Team Interception. CDFA AQW Pest Report No. 18-2016, weekly AQW report: for the week of April 28 to May 04, 2016.

Duan, J. X., W. P. Wu, and X. Z. Liu. 2007. Reinstatement of Coleonaema for Coleophoma oleae and notes on Coleophoma. Fungal Diversity 26: 187-204.

Farr, D. F. and A. Y. Rossman. 2016. Fungal databases, Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved August 24, 2016 from http://nt.ars-grin.gov/fungaldatabases/.

Kusek, C. C. 1995. Cranberry Ripe Rot. In Compendium of Blueberry and Cranberry Diseases Edited by F. L. Caruso and D. C. Ramsdell. APS Press, The American Phytopathological Society, page 43.

Sutton, B. C. 1980. The Coelomycetes. Fungi Imperfecti with pycnidia, acervuli and stromata. Commonwealth Mycological Institute, Kew, Surrey, England, 696 pages

Responsible Party:

John J. Chitambar, Primary Plant Pathologist/Nematologist, California Department of Food and Agriculture, 3294 Meadowview Road, Sacramento, CA 95832. Phone: 916-262-1110, plant.health[@]cdfa.ca.gov.

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