Source: UNIVERSITY OF FLORIDA submitted to
POTENTIAL EFFECTS OF XYLELLA FASTIDIOSA ON SHADE COFFEE ESTABLISHMENT IN PUERTO RICO
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
SPECIAL GRANT
Reporting Frequency
Annual
Accession No.
0219406
Grant No.
2009-34135-20059
Project No.
FLA-NFC-004937
Proposal No.
2009-04424
Multistate No.
(N/A)
Program Code
AH
Project Start Date
Sep 1, 2009
Project End Date
Aug 31, 2012
Grant Year
2009
Project Director
Andersen, P. C.
Recipient Organization
UNIVERSITY OF FLORIDA
G022 MCCARTY HALL
GAINESVILLE,FL 32611
Performing Department
North Florida Research and Education Center, Quincy
Non Technical Summary
Shade coffee offers increased sustainability, prevents erosion and provides ecological diversity compared to monocultures of sun grown coffee. Marketability is substantially higher as input costs (fertilizers/pesticides) are reduced and consumers will pay higher market prices for quality shade coffee. Over 1,000 acres of shade coffee have been planted in Puerto Rico since 2001, and the industry continues to grow. Coffee leaf scorch (CLS) is a primary threat to Puerto Rico; other strains of the bacterium Xylella fastidiosa (Xf) threaten citrus in Puerto Rico and Florida via spread from South/Central America. Our recent study concluded that Xf has not yet invaded Puerto Rico, but the island is highly susceptible to Xf as it contains many Xf host plant species as well as four capable vectors (Cicadellinae) that frequent coffee/citrus plantings. Highest abundances of the most likely vector (Caribovia coffeacola) occur where a common shade plant, Inga vera, is mixed with coffee. Xylem-feeders often require multiple hosts to complete their life cycle. We have confirmed that C. caribovia utilizes I. vera as an oviposition host which may allow it to complete its life cycle with high success in coffee plantings. We have also established that coffee and common shade species in Puerto Rico contain entophytic bacteria that have been shown to be synergistic to Xf growth and establishment. Successful development of the shade plant industry requires consideration of Xf susceptibility. We have quantified the primary shade plants utilized in Puerto Rico. We propose to evaluate each of the predominant shade hosts 1) utilization by potential Xf vectors 2) ability to harbor antagonistic/synergistic endophytic bacteria and 3) direct ability to harbor Xf. This research will also allow the mandatory continued assessment of Xf status in the Caribbean essential for Puerto Rican agriculture. Monitoring Xf in the Caribbean is also essential for safeguarding Florida citrus which is susceptible to Xf; a wide variety of agricultural pests have been introduced to the US via the Caribbean Basin.
Animal Health Component
(N/A)
Research Effort Categories
Basic
50%
Applied
50%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2052232106020%
2110999113010%
2112232113030%
2120999110010%
2122232110030%
Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants; 205 - Plant Management Systems; 212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
2232 - Coffee; 0999 - Citrus, general/other;

Field Of Science
1060 - Biology (whole systems); 1130 - Entomology and acarology; 1100 - Bacteriology;
Goals / Objectives
Shade coffee offers increased sustainability, prevents erosion and provides ecological diversity compared to monocultures of sun grown coffee. Marketability is substantially higher as input costs (fertilizers/pesticides) are reduced and consumers will pay higher market prices for quality shade coffee. Over 1,000 acres of shade coffee have been planted in Puerto Rico since 2001, and the industry continues to grow. Coffee leaf scorch (CLS) is a primary threat to Puerto Rico; other strains of the bacterium Xylella fastidiosa (Xf) threaten citrus in Puerto Rico and Florida via spread from South/Central America. Our recent study concluded that Xf has not yet invaded Puerto Rico, but the island is highly susceptible to Xf as it contains many Xf host plant species as well as four capable vectors (Cicadellinae leafhoppers) that frequent coffee/citrus plantings. Our preliminary surveys show the highest abundances of the most likely vector species occur where a common shade plant, Inga vera, is mixed with coffee. Xylem-feeders often require multiple hosts to complete their life cycle. We have confirmed that these vectors utilize I. vera as an oviposition host which may allow it to complete its life cycle with high success in coffee plantings. We have also established that coffee and common shade species in Puerto Rico contain entophytic bacteria that have been shown to be synergistic to Xf growth and establishment. The primary goal of this project is development of a database to assess Xf susceptibility of potential shade species. This will be done by assessing the following objectives; 1) quantifying each shade plant species abilities to directly harbor Xf. Many species of plants harbor Xf asymptomatically and the susceptibility of many potential shade species is currently unknown; 2) assessing potential vector utilization of each host species, including field abundances as well as establishment of how each host is used by primary vectors (i.e. adult feeding, development and/or oviposition); 3) quantify endophytic bacteria on each shade species as these have often been shown to be antagonistic or synergistic to Xf. The fourth and final objective of this study is continued assessment of the Xf status within Puerto Rico. This is paramount for the coffee and citrus industry in Puerto Rico as well as neighboring islands within the Caribbean Basin. Results of the developed database concerning potential shade hosts susceptibility to Xf will be published and be of value throughout the Caribbean Basin as well as Central America where Xf is already problematic. The potential finding of Xf in Puerto Rico as an invasive species will be immediately reported to appropriate agencies as well as to growers, and we will begin research on control measures based on our experience with these diseases in North America.
Project Methods
Objective 1): Direct ability of shade species to harbor Xf. These experiments will all be conducted in Florida where Xf is already present. All experiments will be conducted in a leafhopper-proof screenhouse at the NFREC-Quincy. We have nursery sources from south Florida for purchasing eight of the ten species that are the most commonly used for shade in Puerto Rico, and are currently searching for the other two species. All species of shade hosts will be inoculated with Xf and the progress of Xf growth will be assessed by PCR at 3 month intervals for a year. Objective 2) Vector use of shade species. Field abundances of vectors will be monitored on shade species that are currently dominant in Puerto Rico. Abundances will be quantified by sticky traps as well as sweeps. Sticky traps assess what leafhoppers are in a planting, whereas sweeps establish exactly what hosts the vectors are residing upon. We will also collect and cage the 4 vector species; choice and no-choice experiments will determine feeding and oviposition preference, adult feeding hosts, and developmental hosts. Objective 3. Endophytic populations within shade plants and adjacent coffee plants. At the farms used in Objective 2, isolations will be made from the major shade species to determine endophytes prevalent in these species. Endophytic populations in adjacent shade coffee and in nearby sun coffee will also be isolated and identified. Comparisons will identify endophytes in each shade host, examine effects on adjacent coffee and provide a general comparison of endophyte populations between sun and shade coffee. Endophytic bacteria will be purified, characterized and identified by traditional, microscopic and biochemical methods. Objective 4): Assessment of Xf in Puerto Rico. One of our most important objectives is to continue to monitor the status of Xf in Puerto Rico. Our designed protocol will allow us to examine the important commodities citrus, avocado, and mango (monitored as shade plants) as well as coffee at a wide variety of sites. At each of the sites collected for Objective 2 (Endophytes) we will collect petioles in a similar fashion for Xf sampling. Xf isolation and analyses will be performed by molecular (PCR) and biochemical methods. One of the primary successes of our previous research was the transfer of knowledge in identifying Xf to researchers in Puerto Rico. We will continue to utilize these skills. Our monitoring of a wide variety of shade coffee farms will allow us to examine a great many coffee and citrus plants in the field, as well as monitoring shade species.

Progress 09/01/09 to 08/31/12

Outputs
OUTPUTS: Shade coffee offers increased sustainability, prevents erosion and provides ecological diversity compared to monocultures of sun grown coffee. More importantly for Puerto Rico, it offers a market window for high-end coffee; Puerto Rican farmers are at a competitive disadvantage for typical sun coffee within the Caribbean Basin due to high labor costs. Diseases caused by the bacterium Xylella fastidiosa (Xf) include coffee leaf scorch (CLS) and citrus variegated chlorosis (CVC); these diseases threaten two of the major agricultural commodities within Puerto Rico. Our research established that four Cicadellinae leafhoppers are capable vectors and frequent coffee/citrus plantings, with Caribovia coffeacola being the most problematic vector. Cicadellinae leafhoppers are highly polyphagous and often utilize multiple host species during their lifecycle. We also established that both coffee and shade species host a diversity of endophytic bacteria that have been shown to antagonize or stimulate Xf growth, depending on bacterial species. Successful development of the shade coffee industry requires consideration of Xf susceptibility, and thus an understanding of shade hosts utilization by both insect vectors and endophytic bacteria. We have quantified the primary shade hosts in Puerto Rico and determined how each host is utilized by both vectors and endophytic bacteria, as well as documenting the effects of shade hosts on vector and bacterial populations within adjacent plantings of coffee. This research has also allowed us to continue to monitor Xf in Puerto Rico. Continued monitoring is required for safeguarding citrus from CVC in Florida. A priority of this research was to transfer the technology for Xf identification to Puerto Rico, so that there now is a mechanism and personnel for monitoringXf within the Caribbean. This research project also served as the basis for the research project for a graduate student to recieve his Masters of Science (December 2012). Additionally, an undergraduate student also conducted an independent project (published) under the guidance of this project. Results from our research have been dissemated at international (Caribbean Food Crop Society) and national (Entomological Society of America, American Phytopahology Society) meetings as well as at local and regional meetings within Puerto Rico (i.e. SOPCA annual meeting and various meetings of coffee producers). Our work involved repeated sampling for 3 years at a dozen on-farm locations, and thus local producers were heavily involved with this project. We also met with other producers to lay the ground work for future research on low-input coffee in Puerto Rico. The final results will also be included in the NFREC-Quincy website. PARTICIPANTS: Peter Andersen (PI; University of Florida) was responsible for planning and coordinating all aspects of research. Mildred Zapata (co-PI; University of Puerto Rico-Mayaguez) responsibilities included coordinating and overseeing all plant pathology portions of this study. Eduardo Schroeder (Co-PI; University of Puerto Rico-Mayaguez) is a specialist in shade coffee production in Puerto Rico and was instrumental in selecting the variety of on-farm sites utilized in these experiments. Brent Brodbeck (collaborator; University of Florida) collected and analyzed the majority of data in entomological experiments. Carlos Bolanos (graduate student; University of Puerto Rico-Mayaguez) conducted field and laboratory experiments on endophytic bacteria found in shade coffee; Mr. Bolanos will graduate with his Masters of Science based on this research project in December, 2012. Alexis Cruz-Gonzales (undergraduate stucdent; University of Puerto Rico-Mayaguez) conducted an independent undergraduate project (published) concerning sharpshooter leafhopppers on weed species in shade coffee plantings. Manuel Cordero (Extension Agent; Jayuya, Puerto Rico) assisted greatly with research at on-farm locations in Jayuya, Puerto Rico. TARGET AUDIENCES: The principal target audience is the coffee producers/consumers of Puerto Rico. The population of coffee farm owners as well as consumers is largely Hispanic/Latino. Data was taken at a dozen on-farm locations throughout the 3 year experiment, and thus required extensive involvement by local producers. The Federal program Coral Reef Initiative is now investing over $1 million in protecting Puerto Rico's coral reefs, and one of the four priority areas is development of the environmentally friendly shade coffee industry. Findings from our experiments will help producers develop coffee shade farms in a manner that minimizes risks of insect pests and plant diseases. A secondary group benefitting from this research is citrus producers in Florida. This research was used to do the first systematic monitoring for the pathogen Xylella fastidiosa in the Caribbean Basin. This pathogen has caused multi-million dollar losses to the citrus industry in South America, and potential movement north threatens the citrus industry in Florida. Thus it is essential that movement of the pathogen into and through the Caribbean Basin is monitored. PROJECT MODIFICATIONS: The only major change in methodology results from technological advances at the molecular level in identification of plant pathogens. We expanded our methodology to include newly developed techniques in PCR as well as DNA sequencing. We also expanded our research concerning endophytic bacteria, as these have been found to have potential impacts on the pathogen Xylella fastidiosa.

Impacts
Our work has established that Caribovia coffeacola is the primary potential vector of Xf in Puerto Rico, distribution is much higher on coffee than citrus, and that C. coffeacola are more abundant at high elevations. Caged choice tests showed that insect vectors utilized shade species variably dependent on host species, with the common shade species Inga vera being a preferred feeding host. Other common shade species such as Andira inermis, Gliricidia sepium or Citrus spp. were much less utilized by vectors. Field populations of vectors in shade plantings mirrored these responses, with vectors being most abundant in shade coffee plantings where I. vera was the only shade species compared to other single shade species or to sun coffe controls. However, vector populations were also low in high diversity plantings where a diversity of shade plants were utilized, even when I. vera was present. Endophytic bacteria showed a variable response with shade treatment, and tended to have higher diversity in shade versus sun coffee. Coffee at higher altitudes (where vectors are present) were 14 times more likely to exhibit symptoms similar to CLS. Tissue from some of these plants tested positive to both CLS Elisa tests and PCR tests. However, molecular sequencing of these bacteria failed to confirm that they were Xf. Until we have positive sequencing confirmation, we regard these symptoms as a result of an unknown disease associated with xylem feeding vectors. Regardless of pathogen identification, Puerto Rico is now investing heavily in development of shade coffee due to economic as well as environmental considerations. This research will help growers to design shade coffee plantings with minimal likelihood of disease infection from xylem feeding vectors. We are working to procure additional funding to further understand how farm landscape and cultural practices impact vector populations, endophytic bacteria and disease presence so that shade plantings resistant to plant pathogens may be developed.

Publications

  • Cruz-Gonzales, A.G., Zapata, M., Brodbeck, B.V. (2011) Weeds and Insects with potential hosts and vectors of disease agents prevalent on shade coffee plantations in two localites in Puerto Rico. Phytopathology 101:276-277.
  • Bolanos, C., Zapata, M., Brodbeck, B.V., Andersen, P.C. (2013) Cluster analysis of coffee trees suspected of Coffee leaf scorch disease in Puerto Rico. Journal of Agriculture of the University of Puerto Rico (pending).
  • Bolanos, C., Zapata, M., Brodbeck, B.V. Andersen, P.C. (2013) Effect of season, shade management and location on endophytic bacteria prevalent in Coffea arabica in Puerto Rico. Journal of Agriculture of the University of Puerto Rico (pending).
  • Zapata, M., Brodbeck, B.V. Andersen, P.C. (2013). Endophytic bacteria from the vascular tissue of coffee (Coffea arabica) and citrus (Citrus sinensis) found during the attempt to isolate the pathogen, Xylella fastidiosa in Puerto Rico. J.Basic Microbiol. (pending) Brodbeck, B.V., Andersen, P.C., Oden S.M., Mizell,R.F. III, McKamey S.M., Zapata, M. (2013) Potential vectors of Xylella fastidiosa and other Auchenorrhyncha on coffee and citrus in Puerto Rico. Brent V. Brodbeck, Peter C. Andersen, Steve Oden, Russell F. Mizell III, Stuart McKamey and Mildred Zapata. Florida Entomologist. (pending)
  • Brodbeck, B.V., Andersen, P.C., Bolanos, C., Zapata, M. (2013) Effects of shade coffee species on the distribution of Cicadellinae leafhoppers. 2013. Environmental Entomology (pending).
  • Andersen, P.C., B.V. Brodbeck, Zapata, M., 2011. Sharpshooter leafhoppers (Cidadellinae:Cicadellidae) and other Hemiptera on coffee and citrus in Puerto Rico. Proc. Southeastern Entomol. Soc. 19-22 March.
  • Brodbeck B.V., Andersen P.C., Schroder E., Bolanos C., Zapata, M. 2011. Proc. Potential Effects of Cicadellinae leafhoppers (Homoptera:Cicadellidae) and other Hemoptera on coffee and citrus in Puerto Rico. 2011. Southeastern Entomol. Soc. 19-22 March.


Progress 09/01/10 to 08/31/11

Outputs
OUTPUTS: Shade coffee offers increased sustainability, prevents erosion and provides ecological diversity compared to monocultures of sun grown coffee. More importantly for Puerto Rico, it offers a market window for high-end coffee; Puerto Rican farmers are at a competitive disadvantage for typical sun coffee within the Caribbean Basin due to high labor costs. Diseases caused by the bacterium Xylella fastidiosa (Xf) include coffee leaf scorch (CLS) and citrus variegated chlorosis (CLS); these diseases threaten two of the major agricultural commodities within Puerto Rico. This bacterium is solely vectored by Cicadellinae leafhoppers that feed on xylem fluid. Our previous research established that four capable vectors frequent coffee/citrus plantings, with Caribovia coffeacola being the most problematic vector. Cicadellinae leafhoppers are highly polyphagous and often utilize multiple host species during their lifecycle. Successful development of the shade coffee industry requires consideration of Xf susceptibility, and thus an understanding of how shade hosts may be utilized by Cicadellinae leafhoppers. We have quantified the primary shade hosts in Puerto Rico and will now determine how each shade host's 1) direct ability to harbor Xf, 2) utilization by Cicadellinae vectors, and 3) presence or absence or bacteria antagonistic or synergistic to Xf in the xylem fluid of each shade species. This research will also allow us to further monitor and quantify the spread of Xf in Puerto Rico. Monitoring Xf in Puerto Rico is also mandatory for safeguarding citrus in Florida. PARTICIPANTS: Peter C. Andersen. PI. Coordinated Project, and assisted in collection of entomological data. Professor of Horticulture. University of Florida. NFREC-Quincy, 155 Quincy, Florida. Mildred Zapata. Co-PI. Responsible for plant pathology aspects of this project. Professor of Plant Pathology. University of Puerto Rico, Mayaguez. Eduardo Schroeder. Co-PI. Extensive experience with coffee in Puerto Rico resulted in contacts for all farm research sites used in this project. Professor of Soil Science. University of Puerto Rico, Mayaguez. Brent V. Brodbeck. Senior Biological Scientist. Conducted insect collections throughout the project. Univeristy of Florida. Carlos Bolanos. Graduate Student. Assisted in plant pathology work on this project. Univesity of Puerto Rico, Mayaguez. TARGET AUDIENCES: Target audiences include all coffee and citrus producers in Puerto Rico. Also all citrus producers in Florida, as Xylella fastidiosa is a potential threat to Florida. Efforts include dissemination of information at the annual meetings of the American Plant Pathology Assiation and the Southeastern Branch of the Entomological Soceity of America held in San Juan, Puerto Rico in May 2011 as well as the annual SOPCA meeting held in Ponce, Puerto Rico in November, 2011. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our work has established that Caribovia coffeacola is the primary potential vector of Xf in Puerto Rico, distribution is much higher on coffee than citrus, and that C. coffeacola are more abundant at high elevations. We note that these results parallel our examination of Xf-like symptoms in Puerto Rico with Xf symptoms being more abundant on coffee than citrus, and most abundant in coffee grown at high elevations. Current molecular work is confirming if this is Xf, identifying the potential subspecies of Xf (subspecies relates to the pathenogenecity in different crop species) or if we are dealing with a new xylem-inhabiting pathogen. We are continuing to monitor potential vectors on different shade plant species (studies to be completed in the summer of 2012) but initial results strongly suggest that different types of shade hosts greatly impact the distribution of potential vectors. High populations of C. coffeacola are often found when the common shade legume Inga vera is used as a dominant shade species. Cicadellinae populations are much lower when other shade hosts such as citrus or moca, or a mixture of shade hosts are present. Insect caging tests confirmed the preference of I. vera as a feeding host for C. caribovia. We have also found that the presence of endophytic bacteria antagonistic to Xf varies greatly with shade host and location. Further understanding of how leafhopper and endophytic bacteria distribution are impacted by shade species are necessary for developing Xf tolerant shade coffee plantings in Puerto Rico.

Publications

  • Marino-Cardenas, Y., M. Zapata, B.V. Brodbeck S. McKamey and P.C. Andersen. 2010. Biodiversity of potential vectors (Insecta:Hemiptera:Auchenorryncha) of Xylella fastidiosa Wells et al. in coffee plants in Puerto Rico. J. of Agric. of Puerto Rico 94:147-164.


Progress 09/01/09 to 08/31/10

Outputs
OUTPUTS: Shade coffee offers increased sustainability, prevents erosion and provides ecological diversity compared to monocultures of sun grown coffee. Marketability is substantially higher as input costs (fertilizers/pesticides) are reduced and consumers will pay higher market prices for quality shade coffee. Over 1,000 acres of shade coffee have been planted in Puerto Rico since 2001, and the industry continues to grow. Coffee leaf scorch (CLS) is a primary threat to Puerto Rico; other strains of the bacterium Xylella fastidiosa (Xf) threaten citrus (citrus variegated chlorosis, CVC) in Puerto Rico and Florida via spread from South/Central America. We have recently confirmed that Xf occurs in Puerto Rico, and we are currently working on Xf strain differentiation. Puerto Rico contains many Xf host plant species as well as four capable vectors (Cicadellinae) that frequent coffee/citrus plantings. Highest abundances of the most likely vector (Caribovia coffeacola) occur where a common shade plant, Inga vera, is mixed with coffee. Xylem-feeders often require multiple hosts to complete their life cycle. We have confirmed that C. caribovia utilizes I. vera as an oviposition host which may allow it to complete its life cycle with high success in coffee plantings. We have also established that coffee and common shade species in Puerto Rico contain entophytic bacteria that have been shown to be synergistic to Xf growth and establishment. Successful development of the shade plant industry requires consideration of Xf susceptibility. We have quantified the primary shade plants utilized in Puerto Rico. We propose to evaluate each of the predominant shade hosts 1) utilization by potential Xf vectors 2) ability to harbor antagonistic/synergistic endophytic bacteria and 3) direct ability to harbor Xf. This research will also allow the mandatory continued assessment of Xf status in the Caribbean essential for agriculture in Puerto Rico. Monitoring Xf in the Caribbean is also essential for safeguarding Florida citrus from CVC since a wide variety of agricultural pests have been introduced to the US via the Caribbean Basin. PARTICIPANTS: Peter C. Andersen, Professor of Horticulture, University of Florida NFREC-Quincy, 155 Research Rd. Quincy FL 32351. Phone: (850) 875-7122. Email: pcand@ufl.edu Mildred Zapata-Serrano, Professor of Plant Pathology, Univerity of Puerto Rico, Crop Protection Dept., PO Box 9030, Mayaguez, Puerto Rico, 00681-9030. Emial: mzapata@uprm.edu Eduardo Schroder, Professor of Plant Pathology, Univerity of Puerto Rico, Crop Protection Dept., PO Box 9030, Mayaguez, Puerto Rico, 00681-9030. Email: escroder@uprm.edu John S. Hartung, Research Leader and Research Plant Pathologist, United States Department of Agriculture Agricultural Research Service, Phone: (301) 504-6374. Email: john.hartung@ars.usda.gov Stuart McKamey, Entomology, Smithsonian National Museum of Natural History. Phone: (202) 633-4562. Email: stuart.mckamey@ars.usda.gov TARGET AUDIENCES: The target audience involves coffee and citrus growers in Puerto Rico. The Carribean basin is the gateway to many insect and disease pests that arrive in Florida. If citrus variegated chlorosis is identified in Puerto Rico then the Florida citrus industry will be alerted to this increased risk. PROJECT MODIFICATIONS: The only major change associated with this project involves the identification of Xylella fastidiosa (Xf) in Puerto Rico. We are currently elucidating the specific strains. If the citrus variegated chlorosis strain is identified in Puerto Rico, it will have a great potential impact on the spread on this disease to Florida.

Impacts
Two of Puerto Rico's principal agricultural commodities, coffee and citrus, are highly susceptible to diseases caused by the xylem-limited bacteria Xylella fastidiosa (Xf). The Xf diseases coffee laef scorch (CLS) and citrus variegated chlorsis (CVC) have been reported in South America and Central America. We have recently confirmed the presence of Xf in Puerto Rico, and we are currently involved in the identification of strains. The Caribbean Basin is a potential gateway for CVC for Florida citrus via northern spread from South America. We surveyed Homoptera in citrus and coffee plantings for 18 months at 3 month intervals throughout western Puerto Rico to detect potential vectors of Xf. Sampling was done by sweep and trap sampling of coffee, citrus and adjacent habitats. Only insects that feed on xylem fluid, sharpshooter leafhoppers (Cicadellidae:Cicadellinae) and froghoppers (Cecropidae), can vector Xf. Over 5,000 Homoptera were collected; roughly 5% of these were xylem feeding insects. However, 4 of the 6 sharpshooter species that have been previously documented in Puerto Rico were shown to be insects frequently collected in citrus and coffee plantings. Two of these species, Hortensia similis and Caribovia coffeaphila, are primarily grass feeders and rarely feed directly on coffee and citrus. Apoganallia sp. were infrequently collected, and often on herbaceous host plant species. Caribovia coffeacola poses the greatest potential threat, commonly being found feeding directly on coffee in plantings at high elevations. Citrus had many fewer potential vectors, as C. Caribovia and H. similis were only rarely found on citrus. Cecropidae were rarely collected feeding on coffee or citrus. Locally high populations of C. coffeacola occurred on coffee grown in proximity to the common shade legume Inga vera, including high populations of immatures rarely noted on coffee. Within farms, we documented that populations of C. coffeacola increased with proximity to I. vera. Field collected C. coffeacola were subjected to choice and no-choice tests to establish insect preference and performance. Caribovia coffeacola preferred both coffee and I. vera over other hosts on which they had been collected including citrus, milkweed (Asclepsia spp.) and grasses. In no-choice tests, C. coffeacola confined on I. vera outperformed similar insects with survivorship, male and female weights significantly exceeding C. coffeacola confined to other hosts including coffee. We are currently investigating the utilization of I. vera and other shade species in order to develop management strategies for shade coffee that do not increase the possibility of Xf infection.

Publications

  • Marino-Cardenas, Y., M. Zapata, B.V. Brodbeck, S. McKamey and P.C. Andersen. 2010. Biodiversity of potential vectors (Insecta: Hemiptera: Auchenorryncha) of Xylella fastidiosa Wells et al. in coffee plants in Puerto Rico. J. of Agric. of Puerto Rico 94:147-164.