California Pest Rating for
Armored scale | Melanaspis leivasi (Costa Lima)
Hemiptera: Diaspididae
Pest Rating: A
PEST RATING PROFILE
Initiating Event:
Melanaspis leivasi was found on Florida stranger fig (Ficus aurea Nutt.) at a residence in West Palm Beach by the Florida Department of Agriculture and Consumer Resources and identified by USDA APHIS on 11/9/2017 (USDA/APHIS/PPQ, 2017). This is the first domestic record for this pest in the United States. In California, it currently has a “Q” rating. Due to its potential economic and environmental impacts, a permanent rating is proposed
History & Status:
Background: Melanaspis is a genus of armored scales that includes 64 described species, of which M. leivasi is the largest, adult females measuring up to 2.4 millimeters in length (Deitz and Davidson, 1986). Melanaspis leivasi has been associated with Anacardium excelsum (Anacardiaceae), Bursera sp. (Burseraceae), Ficus sp. (Moraceae), and Vitis sp. (Vitaceae) (Claps et al., 1999; Garcia Morales et al., 2016).
Worldwide Distribution: Melanaspis leivasi is reported from South America (Brazil and Colombia), Central America (Guatemala and Panama), and Mexico. This species is not known to occur in the continental United States (Garcia Morales et al., 2016).
Official Control: Melanaspis leivasi is not known to be under official control anywhere.
California Distribution: Melanaspis leivasi is not known to occur in California (Symbiota Collections of Arthropods Network).
California Interceptions: Melanaspis leivasi has been intercepted three times in California; all three interceptions were in San Diego on tropical apricot (Mammea americana) from Mexico.
The risk Melanaspis leivasi would pose to California is evaluated below.
Consequences of Introduction:
1) Climate/Host Interaction: Of the four genera of plants that M. leivasi has been associated with, only Vitis is widely distributed in California. The family Anacardiaceae contains other genera in California that could possibly serve as host plants. Because of the apparent restriction to a tropical or subtropical climate, it appears unlikely that M. leivasi could become established in more than a limited portion of California. Therefore, Melanaspis leivasi receives a Medium (2) 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: Melanaspis leivasi has been associated with four families of plants: Anacardiaceae, Burseraceae, Moraceae, and Vitaceae (Garcia Morales et al., 2016). 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: Natural dispersal in diaspidids is limited, because adult females do not fly. They can, however, be artificially dispersed via movement of infested plant material. 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: There is little information available on the biology of Melanaspis leivasi. The genus Melanaspis includes several pest species. Some species are pests in their native range. One, M. deklei, is not known to be a pest in its native range, but became a pest of ornamental wax myrtle trees in South Carolina after it was introduced there (Chong et al., 2009). It is possible that M. leivasi could become an agricultural pest of grapes in California if it became established here; if so, this could lower crop yield, increase production costs, and negatively change normal cultural practices. Therefore, it receives a High (3) in this category.
Economic Impact: A, B, D
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: 3
– 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 genus Melanaspis has a demonstrated pest potential, as several species are economic pests. In addition, M. leivasi apparently feeds on at least four families of plants; some of these families include species native to California. Three members of the Anacardiaceae, Rhus ovata, R. ovatifolia, and Malosma laurina, are prominent or dominant members of shrub-dominated communities in southern California. If this pest were to attack these species and reduce their fitness, then it could cause modification of habitat types including coastal strand, southern sagebrush scrub, sumac scrub, and various types of chaparral. As these plant communities serve as habitat for the federally endangered Least Bell’s vireo (Vireo bellii pusillus), then this pest could indirectly affect this endangered species. Therefore, it receives a High (3) in this category.
Evaluate the environmental impact of the pest on California using the criteria below.
Environmental Impact: A, C
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.
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.
Consequences of Introduction to California for Melanaspis leivasi: 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: Melanaspis leivasi is not known to be present 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:
The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (13)
Uncertainty:
There is significant uncertainty. Little information is available on the biology of M. leivasi. For example, the breadth of its feeding habits is apparently broad, but this is based on a small number of literature records. It is possible that it would feed on a far wider range of host plants. It is also possible that M. leivasi would not be capable of becoming established in California because it requires a tropical climate, although there are areas of subtropical climate in southern California.
Conclusion and Rating Justification:
Melanaspis leivasi is a scale insect with apparently broad feeding habits. It is possible that it could become established in California. This species belongs to a genus with several economic pests, and it is not known to be present in California. However, if this species gets established in California, it could cause significant economic and environmental impacts. For these reasons, an “A” rating is justified.
References:
Chong, J.-H., Hodges, G.S., and M. Samuel-Foo. 2009. First record and management of the armored scale, Melanaspis deklei Dietz & Davidson (Hemiptera: Diaspididae), in South Carolina. Journal of Agricultural and Urban Entomology. 26(2): 63-75.
Claps, L.E., Wolff, V.R.S, and R.H. González. 1999. Catálogo de las especies de Diaspididae (Hemiptera: Coccoides) nativas de Argentina, Brasil y Chile. Insecta Mundi. 13(3-4): 239-256.
Deitz, L.L. and J.A. Davidson. 1986. Synopsis of the armored scale genus Melanaspis in North America (Homoptera: Diaspididae). North Carolina State University, Technical Bulletin No. 279. 92 pp.
García Morales, M., Denno, B.D., Miller, D.R., Miller, G.L., Ben-Dov, Y., and N.B. Hardy. 2016. ScaleNet: A literature-based model of scale insect biology and systematics. Database. doi: 10.1093/database/bav118. http://scalenet.info. Accessed 15 November 2017
http://scalenet.info/catalogue/Melanaspis%20leivasi/
Symbiota Collections of Arthropods Network. Accessed 15 November 2017.
USDA/APHIS/PPQ 2017. PestID record APEMD173124536001
Author:
Kyle Beucke, 1220 N Street, Room 221, Sacramento, CA, 95814, 916-403-6741, plant.health[@]cdfa.ca.gov
Responsible Party:
Jason Leathers, 1220 N Street, Sacramento, CA, 95814, (916) 654-1211, plant.health[@]cdfa.ca.gov.
Comment Period:* CLOSED
12/12/17 – 1/26/18
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Pest Rating: A
Posted by ls
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