2009 - Florida CAPS Small Grain Survey Report
Florida CAPS/DPI Small Grain Survey Trapping Initiative for the Wheat Bug Nysius huttoni White, the Rice Cutworm, Spodoptera litura (F.), the Old World Bollworm, Helicoverpa armigera (Hübner) and the rust Puccinia graminis tritici race Ug99. Leroy Whilby, DPI-CAPS Pest Survey Specialist, and Trevor R. Smith, CAPS State Survey Coordinator Introduction Some of the most important food and feed crops in the United States include wheat, barley, oats and rye. These crops are all important grasses in the family Poaceae and are cultivated worldwide. They are of extreme economic importance to the United States having contributed approximately $8 billion for usage as human food, animal food or forage and fermentation as reported in 2006. Florida’s 2008 wheat acreage was almost double that of 2007 going from 13,000 to 25,000 acres. The value of the 2007 wheat crop was $2,206,000. Florida’s wheat is produced mostly in the northern tier of counties from approximately the Suwannee River to the western border near Pensacola. This 300-plus-mile span encompasses about 14 counties. Figures 1 and 2 show the counties that have wheat and oat producing farms, highlighting the higher producing counties. Several pests represent a threat to the entire industry. These pests include Autographa gamma, Cernuella virgata, Cochlicella barbara, Copitarsia spp., Helicoverpa armigera, Heterodera filipjevi, Heterodera latipons, Heteronychus arator, Lobesia botrana, Meloidogyne artiellia, Nysius huttoni, Peronosclerospora philippinensis, Spodoptera littoralis, and Spodoptera litura. In Florida, there are three commodities mentioned above (wheat, oats and rye) that are grown in quantity. Wheat and oats are more commonly grown followed by small acreages of rye. Most small grains in Florida are grown in the northwest counties of the state located near the Georgia, Alabama state line. Of these counties, the highest producing are Jackson, Escambia and Calhoun. A map of the state delineating these counties can be seen in Fig.1. Although Florida’s acreage is relatively small compared to other states to the north, Florida wheat can serve as a springboard for exotic wheat pests to move northward throughout the wheat production areas, which for 2008 was estimated to be approximately 63.5 million acres. The Florida CAPS program chose to survey for four small grain pests with likely pathways into the state. These pests were the wheat bug Nysius huttoni White, the rice cutworm, Spodoptera litura (F.), the old world bollworm, Helicoverpa armigera (Hübner) and the rust disease caused by Puccinia graminis tritici race Ug99. These four pests pose a serious threat to small grain production in Florida. The objective of this survey was to detect potential populations of these serious exotic plant pests currently not known to occur in the United States. Planting and Harvesting Dates Small grains in Florida are planted from November to December. Wheat is harvested as soon as the wheat is dried down adequately (about 12% moisture) to prevent lodging and weathering losses (yield and lower test weight). The harvest period depends upon the variety with most ready for harvest by mid-May in Florida.
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Target Pests The wheat bug, Nysius huttoni (Fig. 3), is not known to occur in the western hemisphere. This pest is native to New Zealand and has been introduced into several countries in Europe. It is highly polyphagous and can be found on alfalfa, clover, Brassica spp. and many weed species. However, the greatest economic impact these insects have is on small grain crops such as rye, wheat, oat and barley. Both the adult and nymph feed on sap and can attack many parts of the plant including seeds. The saliva produced by this pest affects the gluten proteins. Under outbreak conditions, this pest is known to have damaged over 10,000 tons of wheat in one year and can cause up to 70% mortality in young plants. The wheat bug is typically spread by hitchhiking on fruit and vegetable shipments. The rice cutworm, Spodoptera litura (Figs. 4 and 5), can be found in Southeast Asia, the Pacific Islands and Australia. This pest has the potential to establish and spread across vast tracks of land in the United States. The rice cutworm is a serious pest feeding on a wide range of host plants including wheat, cotton, corn, rice, soybeans, tobacco, vegetables and many ornamentals. Orchid nurseries that have received periodic shipments of Dendrobium spp. or Oncidium spp. from Asia are potential pathways for the introduction of S. litura. The old world bollworm, Helicoverpa armigera (Fig. 6,) occurs on wheat in various parts of the world including Africa, the Mediterranean, Asia, Australia and Oceania. It has been detected in at least 150 countries. Although the primary hosts of H. armigera are thought to be cotton, tomato and maize, the potential host range covers many unrelated plant species. The detection and monitoring of the spread of Puccinia graminis tritici race Ug99 (Fig. 7) is of the utmost importance as most wheat cultivars currently grown in its likely migration path (North Africa to the Arabian Peninsula and then to Middle East and Asia) are highly susceptible to this race. According to the United Nations Food and Agriculture Organization 29 countries in East and North Africa, the Near East, Central and South Asia, account for 37 percent of global wheat production, and are already affected by Ug99 or at potential risk. This pathogen has been detected most recently in Iran. The introduction of Nysius huttoni, Spodoptera litura, Helicoverpa armigera or Ug99 into Florida would have national significance as Florida would be a gateway for these pests to move into other large wheat-growing regions in the northern or western U.S. Survey methods and collection On May 14, 2009, bucket traps were placed at the edge of fields in Escambia, Calhoun and Jackson Counties with two types of lures (Spodoptera litura and Helicoverpa armigera). Moth samples were collected and lures were changed every two weeks until time of crop harvest and sent to the laboratory for analysis. Samples were screened and then analyzed for the two Lepidoptera species of concern. Each time the traps were checked a survey was made of wheat in the environs for symptoms of rust or any other pathogen or insect damage. This was carried out by examining seed heads for Nysius huttoni or any lygeaids that were present, while the leaves and stems were examined for UG 99. Physical surveys were done the last week before crop harvest. A GPS point was recorded at a location on the edge of the field and sweeping to the left of the recorded point along the border of the field and beating to the right of the recorded point (Fig. 8). The sweeping and beating was 3
done every three meters for 30 meters resulting in 10 sweeps per sample and 10 beats per sample. Weeds along the edges of the fields were also swept when present. The sweeping and beating material were placed on white trays for visibility and aspirators used to collect the insects as quickly as possible. The surface of the soil was also examined for insect families with a large pest component and were selectively sampled. The number and type of samples collected were based on the size of the fields and access to the border of the fields. Photographs taken during the survey can be seen in Fig. 9. Aerial maps were prepared for most of the fields surveyed allowing the survey teams to easily locate access points into the fields and to locate the field borders (Fig. 10). Results All samples collected during this survey were submitted to the appropriate laboratories at the Division of Plant Industry for screening and proper identification. All samples were negative for the target species. From the counties surveyed (Escambia, Calhoun, Jackson, Columbia) approximately 2,400 acres of small grains including wheat, oat and rye were surveyed. A total of 2,353 arthropods were screened consisting of 905 specimens from bucket traps, 832 specimens from sweeping/beating and 616 specimens from blacklight traps. This survey resulted in 35 New County Records (NCR) and two New State Records (NSR) one of which was an arachnid. Of the 35 NCR, 31 were considered to be pests. Acknowledgements Dr. Adam Silagyi, USDA-CAPS – Pest Survey Specialist; Julieta Brambila, USDA – Eastern Region Identifier; Katherine Okins FDACS-CAPS – Laboratory Technician; Libbie Johnson, IFAS Extension, Pensacola, Escambia County; Judith Ludlow, IFAS Extension, Blountstown, Calhoun County; Clyde Smith, IFAS Extension, Mariana, Jackson County; Bill Thomas, IFAS Extension, Lake City, Columbia County; Robbie Robinson, FDACS-DPI – Plant Inspector; Dr. Edward Hung, FDACS-CAPS - Pest Survey Specialist; Cynthia Moncrief, CAPS – Public Information Specialist & NAPIS data manager; David Saeger, CAPS – GIS/Mapping Specialist.
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Figure 1. Wheat production by acreage and number of farms in 2007.
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Figure. 2. Oat production by acreage and number of farms in 2007.
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Figure 3. Dorsal view of Nysius huttoni. Photography credit: N. Wright, DPI.
Figure 4. Lateral view of Spodoptera litura. Photography credit: E. Neering CAB.
Figure 5. Dorsal view of Spodoptera litura. Photography credit: N. Wright, DPI. 7
Figure. 6. Dorso-lateral view of Helicoverpa armigera. Photography credit: Paolo Mazzei, Bugwood.org.
Figure. 7. Close-up of stem rust on wheat. (Photography credit: Cereal Disease Lab, USDA). Field Border
Grain Field
GPS Sweep
Beat
Figure.8: Sweeping and beating sampling procedure. 8
A.
B.
D.
E.
G.
C.
F.
H.
Figure 9. A.) Dr. Adam Silagyi setting bucket trap; B.) Dr. Leroy Whilby recording GPS coordinates for light trap; C.) Libbie Johnson preparing sampling bottles; D.) Robbie Robinson inspecting wheat leaves; E.) Julieta Brambila collecting surface samples with aspirator; F.) Dr. Adam Silagyi collecting beat sample. G.) Dr. Leroy Whilby collecting a sweep sample; H.) Dr. Edward Hung examining sweep sample. Photography credit: Dr. Leroy Whilby and Dr. Adam Silagyi. 9
Figure 10. Map of a wheat field selected for survey in 2009 CAPS small Grains Survey.
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Target Pests The wheat bug, Nysius huttoni (Fig. 3), is not known to occur in the western hemisphere. This pest is native to New Zealand and has been introduced into several countries in Europe. It is highly polyphagous and can be found on alfalfa, clover, Brassica spp. and many weed species. However, the greatest economic impact these insects have is on small grain crops such as rye, wheat, oat and barley. Both the adult and nymph feed on sap and can attack many parts of the plant including seeds. The saliva produced by this pest affects the gluten proteins. Under outbreak conditions, this pest is known to have damaged over 10,000 tons of wheat in one year and can cause up to 70% mortality in young plants. The wheat bug is typically spread by hitchhiking on fruit and vegetable shipments. The rice cutworm, Spodoptera litura (Figs. 4 and 5), can be found in Southeast Asia, the Pacific Islands and Australia. This pest has the potential to establish and spread across vast tracks of land in the United States. The rice cutworm is a serious pest feeding on a wide range of host plants including wheat, cotton, corn, rice, soybeans, tobacco, vegetables and many ornamentals. Orchid nurseries that have received periodic shipments of Dendrobium spp. or Oncidium spp. from Asia are potential pathways for the introduction of S. litura. The old world bollworm, Helicoverpa armigera (Fig. 6,) occurs on wheat in various parts of the world including Africa, the Mediterranean, Asia, Australia and Oceania. It has been detected in at least 150 countries. Although the primary hosts of H. armigera are thought to be cotton, tomato and maize, the potential host range covers many unrelated plant species. The detection and monitoring of the spread of Puccinia graminis tritici race Ug99 (Fig. 7) is of the utmost importance as most wheat cultivars currently grown in its likely migration path (North Africa to the Arabian Peninsula and then to Middle East and Asia) are highly susceptible to this race. According to the United Nations Food and Agriculture Organization 29 countries in East and North Africa, the Near East, Central and South Asia, account for 37 percent of global wheat production, and are already affected by Ug99 or at potential risk. This pathogen has been detected most recently in Iran. The introduction of Nysius huttoni, Spodoptera litura, Helicoverpa armigera or Ug99 into Florida would have national significance as Florida would be a gateway for these pests to move into other large wheat-growing regions in the northern or western U.S. Survey methods and collection On May 14, 2009, bucket traps were placed at the edge of fields in Escambia, Calhoun and Jackson Counties with two types of lures (Spodoptera litura and Helicoverpa armigera). Moth samples were collected and lures were changed every two weeks until time of crop harvest and sent to the laboratory for analysis. Samples were screened and then analyzed for the two Lepidoptera species of concern. Each time the traps were checked a survey was made of wheat in the environs for symptoms of rust or any other pathogen or insect damage. This was carried out by examining seed heads for Nysius huttoni or any lygeaids that were present, while the leaves and stems were examined for UG 99. Physical surveys were done the last week before crop harvest. A GPS point was recorded at a location on the edge of the field and sweeping to the left of the recorded point along the border of the field and beating to the right of the recorded point (Fig. 8). The sweeping and beating was 3
done every three meters for 30 meters resulting in 10 sweeps per sample and 10 beats per sample. Weeds along the edges of the fields were also swept when present. The sweeping and beating material were placed on white trays for visibility and aspirators used to collect the insects as quickly as possible. The surface of the soil was also examined for insect families with a large pest component and were selectively sampled. The number and type of samples collected were based on the size of the fields and access to the border of the fields. Photographs taken during the survey can be seen in Fig. 9. Aerial maps were prepared for most of the fields surveyed allowing the survey teams to easily locate access points into the fields and to locate the field borders (Fig. 10). Results All samples collected during this survey were submitted to the appropriate laboratories at the Division of Plant Industry for screening and proper identification. All samples were negative for the target species. From the counties surveyed (Escambia, Calhoun, Jackson, Columbia) approximately 2,400 acres of small grains including wheat, oat and rye were surveyed. A total of 2,353 arthropods were screened consisting of 905 specimens from bucket traps, 832 specimens from sweeping/beating and 616 specimens from blacklight traps. This survey resulted in 35 New County Records (NCR) and two New State Records (NSR) one of which was an arachnid. Of the 35 NCR, 31 were considered to be pests. Acknowledgements Dr. Adam Silagyi, USDA-CAPS – Pest Survey Specialist; Julieta Brambila, USDA – Eastern Region Identifier; Katherine Okins FDACS-CAPS – Laboratory Technician; Libbie Johnson, IFAS Extension, Pensacola, Escambia County; Judith Ludlow, IFAS Extension, Blountstown, Calhoun County; Clyde Smith, IFAS Extension, Mariana, Jackson County; Bill Thomas, IFAS Extension, Lake City, Columbia County; Robbie Robinson, FDACS-DPI – Plant Inspector; Dr. Edward Hung, FDACS-CAPS - Pest Survey Specialist; Cynthia Moncrief, CAPS – Public Information Specialist & NAPIS data manager; David Saeger, CAPS – GIS/Mapping Specialist.
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Figure 1. Wheat production by acreage and number of farms in 2007.
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Figure. 2. Oat production by acreage and number of farms in 2007.
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Figure 3. Dorsal view of Nysius huttoni. Photography credit: N. Wright, DPI.
Figure 4. Lateral view of Spodoptera litura. Photography credit: E. Neering CAB.
Figure 5. Dorsal view of Spodoptera litura. Photography credit: N. Wright, DPI. 7
Figure. 6. Dorso-lateral view of Helicoverpa armigera. Photography credit: Paolo Mazzei, Bugwood.org.
Figure. 7. Close-up of stem rust on wheat. (Photography credit: Cereal Disease Lab, USDA). Field Border
Grain Field
GPS Sweep
Beat
Figure.8: Sweeping and beating sampling procedure. 8
A.
B.
D.
E.
G.
C.
F.
H.
Figure 9. A.) Dr. Adam Silagyi setting bucket trap; B.) Dr. Leroy Whilby recording GPS coordinates for light trap; C.) Libbie Johnson preparing sampling bottles; D.) Robbie Robinson inspecting wheat leaves; E.) Julieta Brambila collecting surface samples with aspirator; F.) Dr. Adam Silagyi collecting beat sample. G.) Dr. Leroy Whilby collecting a sweep sample; H.) Dr. Edward Hung examining sweep sample. Photography credit: Dr. Leroy Whilby and Dr. Adam Silagyi. 9
Figure 10. Map of a wheat field selected for survey in 2009 CAPS small Grains Survey.
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