California Pest Rating Proposal for
Chrysodeixis includens (Walker): soybean looper
Current Pest Rating: Q
Proposed Pest Rating: A
Comment Period: 10/19/18 – 12/03/18
Chrysodeixis includens (Walker) is reported as a key pest of soybean in parts of North and South America, and all Central America. It is often confused with the cabbage looper [(Trichoplusia ni (Hubner)] which is similar in size and appearance. It was recently intercepted on a shipment of cut foliage from Florida. This species has a temporary Q rating. A pest rating proposal is required to assign a permanent rating.
Pseudopulsia includens (Goater et.al. 2003)
History & Status:
Background Chrysodeixis includens is primarily a foliage feeder but it also feeds on pods or fruits (Carter et.al. 2017). The most destructive stage of this pest is the larval or caterpillar stage. Caterpillars are light green in color with white lines running along their body length (Grains SA, 2017). Larger larvae feed on entire plants, can completely defoliate plants; their damage continues by feeding on soybean pods later. Adult moths feed solely on flower nectar. Although it’s a major pest of soybean, C. includens feeds on many other agronomic, vegetable and floricultural crops. (Carter et.al., 2017)
The soybean looper attacks the lower canopy after hatching. Feeding generally starts from inside the canopy and moves up and outward. This feeding pattern can be easily overlooked when scouting for pests as the outer canopy appear undamaged. Most foliage is consumed by later instars during the last 4-5 days of the larval stage.
Chrysodeixis includens is widely distributed throughout North America. In addition, it is present in Central America, the Caribbean, South America and Oceania and the Unites States (CABI, 2018).
Chrysodeixis includens occurs throughout the United States. However, the worst infestations of this pest on soybean occur in Texas, Arkansas, Mississippi, Alabama, Georgia, and South Carolina (Herzog, 1980).
Official Control: Chrysodeixis includens has been listed as a harmful organism in Guatemala, India, Japan, Panama and Philippines (PCIT, 2018).
California Distribution: Chrysodeixis includens has never been found in the natural environment of California.
California Interceptions: Chrysodeixis includens has been intercepted by CDFA through border stations inspections, state exterior quarantine and high risk pest exclusion activities (CDFA Pest and Damage Report Database, 2018)
The risk Chrysodeixis includens (soybean looper) would pose to California is evaluated below.
Consequences of Introduction:
1) Climate/Host Interaction: Chrysodeixis includens is active throughout the winter in tropical areas of the New World. It overwinters in sub-tropical regions of North and South America. In the United States, it overwinters in south Florida and south Texas. Host plants at the time of flowering or fruiting, are most attractive to ovipositing adults (CABI, 2018). Broad climatic tolerances of this species and the presence of many potential host plants throughout California suggests that includens could become established much over California. It receives a High (3) in this category.
Evaluate if the pest would have suitable hosts and climate to establish in California:
– 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: Chrysodeixis includens has been recorded on 174 host plants across 39 plant families; with most hosts belonging to the families Asteraceae Solanaceae, Fabaceae, Lamiaceae, Brassicaceae, Poaceae, Amaranthaceae, Euphorbiaceae, and Malvaceae (Specht, 2015). It is considered a major pest of soybean but also attacks cotton, sunflower, lettuce, cabbage, broccoli, sweet potato, cucumber, common bean, pea, sugarcane, sorghum, maize, wheat and tomato. Besides the large number of cultivated crop species, includens also feeds on weeds and native plants. It receives a High (3) in this category.
Evaluate the host range of the pest:
– 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: Chrysodeixis includens undergoes complete metamorphosis (egg, larva, pupa and adult life stages). Adult female deposits eggs on undersides of soybean leaves. It lays approximately 640 eggs over her life span. Eggs hatch in 3 days and go through 6 larval stages in about 14 days. The life cycle is completed in 27 days (Soybean Insect Guide, 2011). Dispersal can occur through flight of adult moths and migrant populations from areas where it overwinters. It receives a Medium (2) in this category
Evaluate the natural and artificial dispersal potential of the pest:
– 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: Chrysodeixis includens is mainly a foliage feeder but also feeds on pods or fruits. On soybean, it feeds from the lower, interior canopy, moving up and outward. Most foliage is consumed by later instars during the last 4-5 days of the larval stage (Smith, 1994). This species is reported to cause economic damage on table legumes, floriculture crops, sweet corn ears, yam and passion flower (Spelch et.al, 2015). All these crops are cultivated in California. More than 90% damaged tomato crop has been reported during heavy infestations in Puerto Rico (Plant Wise Knowledge Bank, 2018). This species has been shown to develop resistance to commonly-used insecticides. It receives a High (3) in this category.
Evaluate the economic impact of the pest to California using the criteria below:
Economic Impact: A, B, C, 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: Chrysodeixis includens is not likely to lower biodiversity and disrupt natural communities. It is also not likely to impact major endangered and threatened species in California. If this species gets introduced from southern states to California, it would trigger private treatments in garden plantings. 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.
Score the pest for Environmental Impact:
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 Chrysodeixis includes (soybean looper): 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: Chrysodeixis includens (soybean looper) has never been found in the environment 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.
The final score is the consequences of introduction score minus the post entry distribution and survey information score: High (13).
Chrysodeixis includens has been intercepted over the years by CDFA however it has not been able to spread and get established. Since it overwinters in south Florida and south Texas, the possibility of its introduction as a migrant moth cannot be underestimated, however there are not many well documented studies of its life history. The wide range of host availability in California can likely serve as source for its establishment once it gets introduced. Since soybean is not cultivated in large areas of the California, the economic impacts would be likely concentrated to tomato and other widely grown host plants.
Conclusion and Rating Justification:
Chrysodeixis includens has not been reported in California. If this species gets introduced and established in the state, it may likely have significant economic and environmental impacts, mainly due to the wide range of plants it attacks , being cultivated in California. An “A”-rating is justified.
CABI 2018. Crop Protection Compendium. Datasheet: Chrysodeixis includens (soybean looper). Accessed 6/25/2018: https://www.cabi.org/cpc/datasheet/13245
Carter, E and Gillett-Kaufman, J.L. 2017. Featured Creatures: Soybean Looper Chrysodeixis includens (Walker). Entomology and Nematology Department, University of Florida. Accessed 6/25/2018. http://entnemdept.ufl.edu/creatures/field/soybean_looper.htm
Goater, B., Ronkay, L. and Fibiger, M., 2003. Noctuidae Europaeae. Catocalinae, Plusiinae,vol. 10. Entomological Press, Sorø
Grain SA, 2017. Pseudoplusia includens (Walker): Soybean Looper. Association of Grain farmers in South Africa. Accessed 6/26/2018 http://www.grainsa.co.za/pages/grain-research/crop-protection/economically-important-pest-and-diseases/soybean-looper
Herzog D.C. 1980. Sampling soybean looper on soybean. pp. 141-168. In Kogan M, Herzog DC (Eds.) Sampling Methods in Soybean Entomology. Springer, New York, USA. Assessed 6/26/2018 https://link.springer.com/chapter/10.1007/978-1-4612-9998-1_7
Pest and Damage Record Database. Pest Prevention and Plant Health Services. California Department of Food and Agriculture. Accessed 6/25/2018: http://phpps.cdfa.ca.gov/user/frmLogon2.asp
CABI Plantwise, 2018. Plantwise Knowledge Bank. Plantwise Technical Factsheet. Soybean looper (Chrysodeixis includens). Accessed 6/27/2018:
Soybean Insects Guide, 2011. Soybean looper: Biology and Ecology. Department of Entomology. Iowa State University. Accessed 6/27/2018: https://www.ent.iastate.edu/soybeaninsects/node/338
Smith R.H., Freeman B and Foshee W. 1994. Soybean loopers: Late season foliage feeders on cotton. Alabama Extension. Circular ANR-843.
Specht A, de Paula-Moraes S.V. and Sosa-Gomez, D.R. 2015. Host plants of Chrysodeixis includens (Walker) (Lepidoptera, Noctuidae, Plusiinae). Revista Brasileira de Entomologia 59: 343-345.
USDA Phytosanitary Certificate Issuance & Tracking System (PCIT) Phytosanitary Export Database (PExD). Accessed 6/25/2018. https://pcit.aphis.usda.gov/PExD/faces/PExDReport.jsp
Raj Randhawa, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 403-6617, plant. health[@]cdfa.ca.gov.
Kyle Beucke, 1220 ‘N’ Street, Room 221, Sacramento CA 95814, (916) 654-1211, plant.health[@] cdfa.ca.gov.
10/19/18 – 12/03/18
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Proposed Pest Rating: A
Posted by ls