Increasing Ecological Insect Pest Management on Guam Through Building Agriculture Professionals' Understanding of Semiochemicals

Final Report for EW09-012

Project Type: Professional Development Program
Funds awarded in 2009: $59,990.00
Projected End Date: 12/31/2011
Region: Western
State: Guam
Principal Investigator:
Gadi V.P. Reddy, Ph.D.
University of Guam
Co-Investigators:
Dr. Michael Ivie
Montana State University-Bozeman
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Project Information

Abstract:

Phase 1 Course Development: over the course of 18 months, semiochemical-based trapping methods were developed for the control of the banana weevil, Cosmopolites sordidus, the New Guinea sugarcane weevil, Rhabdoscelus obscurus, and the sweetpotato weevil, Cylas formicarius (Coleoptera: Curculionidae). Photos of trapping systems as well as trapping dates were collected and developed into an instruction manual titled: SEMIOCHEMICAL-BASED TRAPPING METHOD FOR WEEVIL PESTS ON GUAM. This manual was supplied to the Agricultural Professionals on Guam and the Northern Marianas Islands. During the second year, the Instruction, Field day and Evaluation were carried out.

Project Objectives:

Phase 1 Course Development: During this phase of the project, general trapping methods on Guam will be subjected to various semiochemical-based lures, which characterizes local production. The semiochemical-based trapping method will be photographed and lures will be evaluated for use. A survey of 10 farms will be conducted to evaluate current growers’ knowledge and farm practices. Crops will be evaluated for the nature of pest damage and symptoms based on the semiochemical-based trapping method. A follow-up survey will be conducted on these same farms at the end of the project to evaluate the impact of the capacity building on agriculture professionals and the impact the field day had on their knowledge and practices. The guide will cover the relationship between semiochemicals and overall crop production/health on Guam for the four different methods.
Phase 2 Instruction: For four months, 10 agriculture professionals using material developed in phase one of this project, will be instructed in the benefits and method of use of the trapping method for all the four weevil pests. Class will meet twice a month for three hour sessions. Participants from each of the agencies that advise farmers on semiochemical issues will be selected: University Cooperative Extension Service, Guam Department of Agriculture, National Resource Conservation Service, and University faculty and staff. The pool of participants will be drawn from various disciplines: entomology, horticulture, agronomy, and 4-H. At least one of the participants will be from the private sector, an individual that is directly involved with application and evaluation of the requirements on a daily basis for clientele. A holistic approach to instruction will be taken. First, the instruction manual will be thoroughly studied. Students will be given hands-on field experience and tested with real world problems. Finally, at the end of the 4 month program, the students will host a field day where they will have an opportunity to demonstrate their skills to the growers and the general public. Different trap designs and semiochemical lures as well as appropriate trapping methods will be used. Participants will develop, maintain, and collect data on field demonstration plots that simulate real problems on Guam. Plots amended with various traps will be evaluated for crop health, symptoms, and insect pests. These plots will be a part of the field day demonstration, which the participants will host for growers and the public.
Phase 3 Field Day and Evaluation: Agriculture professional trainees will host a field day for growers and the general public. The inclusion of the field day into this project provides a form by which the agriculture professionals demonstrate their new found knowledge and can begin the process of educating the farming community and the general public. The field day also provides the farming community a chance to see firsthand the benefits and cost savings of proper trap designs. Funds will be dedicated within the project to bring one agriculture professional from Saipan and Rota, which are two of Guam’s largest neighboring islands. Additionally, Dr. Robert K. Vander Meer, Research Leader at USDA-ARS, Gainesville will be invited to give a special lecture on the use of semiochemicals in monitoring and more effective control of invasive pest ants and Rhinoceros beetles (Oryctus rhinoceros (Coleoptera: Scarabaeidae) that threaten agriculture and the ecology of Guam. The project will be evaluated by means of a farm survey and testing by participating agriculture professionals. Two months after the field day, a follow-up survey of the farms visited during the course development phase of the project will be conducted to evaluate the impact of the capacity building of Guam’s agriculture professionals and the impact the project’s field day had on their knowledge and practices. Also, within this period of time the agriculture professionals will meet one more time to provide feed-back on the effectiveness of the program and to evaluate long term gains in their knowledge of semiochemicals and weevil control.

Introduction:

Guam is the western most territory of the United States. It is located south of Japan and east of the Philippines at approximately 144? E and 13? N. Its climate is maritime tropical and it is seasonally subject to frequent passages of tropical low-pressure areas and occasional typhoons. Its population is ethnically diverse, consisting primarily of Chamorro, Filipinos, US mainland Americans, Koreans, Japanese, Chinese, Indians and Carolinian Islanders. Its economy is based on Asian tourism and the presence of US military facilities on the island (Osman, 1995).
Agriculture has played a relatively minor role in the island’s economy since the drastic changes that took place at the end of the Second World War (WWII) and during the post-WWII military build-up of the island. More than 90 percent of the island’s food supply is imported. By value, the major component of agriculture on Guam is the production of fresh produce for local markets. Fruits and vegetables accounted for 81.3 percent of the value of agricultural production on Guam.
In the past years, most banana produce found in the local markets were imported from other countries. Today, banana growing has become increasingly popular among local farmers in Guam and other neighboring islands. Banana plantations continue to be on the rise and can be seen throughout the island. The fact that the banana weevil is present on Guam and other Pacific Islands raises concern among local growers, consumers, and scientists alike. The weevils are causing yield reductions through the impeding of banana sucker establishment in newly planted crops resulting in loss of plant vigor and reduction in bunch size. It can cause a yield loss of up to 100% if left uncontrolled.
Guam (and the whole of Micronesia, for that matter) is in the midst of a decline of banana production. Thousands of trees are dying in this region due to the banana weevil, Cosmopolites sordidus (Coleoptera: Curculionidae). The banana root borer Cosmopolites sordidus, is considered one of the major pests in most banana growing regions of the world, particularly on dessert bananas, those that can be eaten only when fully ripe, and plantains, those generally known as cooking bananas (Sikora et al., 1989). While various control methods do exist, chemical application is both undesirable and expensive and biological control plays a limited role. Therefore, other means to control the banana weevil population must be further looked into. The existing pheromone-based trapping method using mahogany-brown ground traps 40 × 25 cm appears to be the most efficient at catching C. sordidus adults and has the greatest potential for use in mass trapping and programs for eradication of this pest (Reddy et al. 2008). Without taking appropriate effective control or implementing eradication methods, the banana borer is likely to cause huge or complete loss of banana production in Guam and other Micronesian Islands.
The New Guinea sugarcane weevil, Rhabdoscelus obscurus (Coleoptera: Curculionidae), originated in New Ireland, Papua New Guinea. It was reported that the original habitat of this weevil was New Guinea and the adjoining islands (Reddy et al. 2005). It has since spread to most islands in the Pacific, including Australia and Indonesia. Dispersal of the weevil was almost certainly associated with inter-island trading of sugarcane in earlier years, but in recent years, palms introduced for the ornamental horticultural industry have become the most favored host for this weevil. Especially evident on Guam, R. obscurus has become a major pest of ornamental palms, betel nut palm (Areca catechu), coconut palm (Cocos nucifera) and sugarcane (Saccharum officinarum). The most affected plants are coconut, betel nut, champagne palm (Hyophorbe lagenicaulis), pritchardia palm (Pritchardia pacifica), pygmy date palm (Phoenix roebelenii), Alexander palm (Archontophoenix alexandrae), royal palm (Roystonea regia) and date palm (Phoenix canariensis). Plant nurseries, hotels and gardens containing various ornamental palms are affected considerably by this pest weevil. The damage caused by the boring of this insect is evident on the trunks of the palms. If the damage becomes severe, it can ultimately cause death. More recently, local farmers on Guam have been complaining of noticeable damage occurring on coconut trees on their lands. While conducting a routine survey on R. obscurus throughout the island, our research team had stopped by a particular farmers home to find not only what appeared to be damage caused by R. obscurus on the trunk, but also damage beneath the fibrous sheaths, with adult weevils being found present as well. The coconut tree is extremely valuable to Guam and the Northern Marianas, as it has many different uses. With the recent introduction and attack of the rhinoceros beetle Xyloryctes jamaicensis (Coleoptera : Scarabaeidae) on the coconut tree, any secondary infestation, particularly that more recently seen on Guam by R. obscurus could prove fatal for coconut trees in this region. It is therefore vital that steps be taken to control or eradicate this weevil before it is too late. The chemical ecology laboratory in Guam has developed a trapping method to suppress the R. obscures (Muniappan et al. 2004; Reddy et al. 2005).
The major crop on Guam and the Commonwealth of the Northern Mariana Islands (CNMI) that experiences extensive insect damage is the sweet potato, Ipomoea batatas. Infestations of the sweet potato weevil are so severe on Guam and the Northern Mariana Islands (Saipan, Rota, and Tinian) that many local producers have considered giving up growing sweet potato, which for some may mean abandoning the crop entirely. In fact, there is not just one, but three different species (one which is so far unidentified) of sweet potato weevils already occurring on sweet potato crops in the Northern Mariana Islands. The extensive damage caused by the two sweet potato weevils, Cylas formicarius and West Indian sweet potato weevil Euscepes postfasciatus (Coleoptera: Curculionidae) upon these crops can be devastating to farmers and their workers alike, as it is clear by the numerous sweet potato stands seen alongside the road, that many depend exclusively on this crop for their livelihood. The situation in these regions is made worse by the lack of information and familiarity among growers concerning newer pesticide chemistries, such as imidacloprid and spinosid, and also semiochemical-based trapping methods and new bio-insecticides such as Bacillus thuringiensis. Less-toxic alternatives such as soaps and oils have likewise not been widely promoted on the islands. There is a dire need not only to control the sweet potato weevil but also to educate both farmers and the public alike, otherwise, both Guam and the CNMI will possibly lose another very important crop. The semiochemical-based trapping method has been very effective in reducing pest population and increasing the yield (Heath et al. 1986; Hwang et al. 1991; Yasuda, 1998).
Finally, there is a lack of local knowledge about the role of semiochemicals in pest management. Therefore, there is an urgent need to train the agricultural professionals on the semiochemical-based trapping method for the control of important weevil pests (C. sordidus, R. obscurus, C. formicarius and E. postfasciatus) on Guam.
The purpose of this project is to build agriculture professionals’ understanding of the role of semiochemicals in insect control and pest management and to assist agriculture professionals in passing their knowledge to growers. Guam’s agriculture professional are generally locally trained with minimal exposure to the finer nuances of semiochemicals. Guam College of Natural and Applied Sciences/Cooperative Extension currently has a chemical ecology laboratory that can provide information about various semiochemical availability and methods of use (Reddy and Guerrero, 2004). The laboratory has been very active in conducting research in the area of chemical ecology and has published several scientific papers (for example: Muniappan et al. 2004; Reddy et al. 2005; Reddy et al. 2008). These publications,along with many others, would serve as this project’s training material and would include discussions on semiochemicals of the banana weevil, Cosmopolites sordidus, the New Guinea sugarcane weevil, Rhabdoscelus obscures, and two sweet potato weevils, Cylas formicarius and West Indian sweet potato weevil, Euscepes postfasciatus (Coleoptera: Curculionidae) with accompanying photographs of trapping materials. The publications would also discuss the purchase and use of various traps and lures and general trapping method.

Cooperators

Click linked name(s) to expand
  • Jesse P. Bamba
  • Jack A. Tenorio, Ph.D.
  • Robert K. Vander Meer, Ph.D.

Education & Outreach Initiatives

Objective:
Description:

Methods

Phase 1 Course Development: The development of the guide took 18 months and involved faculty and students from University of Guam Western Pacific Tropical Research Center and College of Natural and Applied Sciences/Cooperative Extension and the United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Gainesville. Of all the mainland US agriculture areas, Florida had the most in common with Guam with respect to climate, crops, insect pests, and soils. During this phase of the project, general trapping methods on Guam was subjected to various semiochemical-based lures, which typifies Guam’s production. The semiochemical-based trapping method has been developed and photographed and its lures have been evaluated for Guam’s use. A survey of 10 farms was conducted to evaluate current growers’ knowledge and farm practices. Crops have also been evaluated for the nature of pest damage and symptoms based on the semiochemical-based trapping method. A follow-up survey was conducted on these same farms at the end of the project to evaluate the impact of the capacity building on Guam’s agriculture professionals and the impact the project’s field day had on their knowledge and practices.
The guide is to cover the relationship between semiochemicals and overall crop production/ health on Guam for the four different methods.
Phase 2 Instruction: For four months, 10 agriculture professionals using material developed in phase one of this project, was instructed in the benefits and method of use of the trapping method for all the three weevil pests. Participants from each of the agencies that advise farmers on semiochemical issues were selected: University Cooperative Extension Service, Guam Department of Agriculture, National Resource Conservation Service, and University faculty and staff. The pool of participants was from various disciplines: entomology, horticulture, agronomy, and 4-H.
A holistic approach to instruction was taken. First, the instruction manual was thoroughly studied. Students were given hands-on field experience and tested with real world problems. Finally, at the end of the 4 month program, the students hosted a field day where they will have an opportunity to demonstrate their skills to the growers and the general public.
Different trap designs and semiochemical lures as well as appropriate trapping methods have been used. Participants have developed, maintained, and collected data on field demonstration plots that simulate real problems on Guam. Plots amended with various traps were evaluated for crop health, symptoms, and insect pests. These plots are a part of the field day demonstration, which the participants will host for growers and the public.
Phase 3 Field Day and Evaluation: Agriculture professional trainees hosted a field day for growers and the general public. The inclusion of the field day into this project provided a form by which the agriculture professionals demonstrate their new found knowledge and begin the process of educating the farming community and the general public. The field day also provided the farming community a chance to see firsthand the benefits and cost savings of proper trap designs. Funds are dedicated within the project. One agriculture professional was brought in from Saipan and Rota, two of Guam’s largest neighboring islands. Additionally, Dr. Robert K. Vander Meer, Research Leader at USDA-ARS, Gainesville attended the workshop to give a special lecture on the use of semiochemicals in monitoring and more effective control of invasive pest ants and Rhinoceros beetles (Oryctus rhinoceros (Coleoptera: Scarabaeidae) that threaten agriculture and the ecology of Guam.
The project was evaluated by means of farm surveying and testing by participating agriculture professionals. Two months after the field day, a follow-up survey of the farmers visited during the course development phase of the project is conducted to evaluate the impact of the capacity building of Guam’s agriculture professionals and the impact the project’s field day had on their knowledge and practices. Also within this period of time, the agriculture professionals are to meet one more time to provide feed-back on the effectiveness of the program and to evaluate long term gains in their knowledge of semiochemicals and weevil control.

Outreach and Publications

The following publications are yielded from the project.

Reddy, G. V. P. 2011. Semiochemical-based Trapping Methods for Weevil Pests on Guam, Western pacific Tropical Research Center, University of Guam, 19p.

Reddy, G. V. P., S. Balakrishnan, J. E. Remolona, R. Kikuchi and J.P. Bamba. 2011.Influence of trap type, size, color, and trapping location on the capture of the New Guinea sugarcane weevil, Rhabdoscelus obscurus (Coleoptera: Curculionidae). Annals of the Entomological Society of America 104: 594–603.

Reddy, G.V.P., and A. Raman. 2011. Visual cues are relevant in behavioral control measures for Cosmopolites sordidus (Coleoptera: Curculionidae). Journal of Economic Entomology 104: 436–442.

Reddy, G.V.P. 2012. Recent trends in the olfactory responses of insect natural enemies to plant volatiles, In: Biocommunication of Plants (Editors: G. Witzany and F. Baluska), Springer-Verlag Berlin Heidelberg, Germany.

The Professional Development Program (PDP) of the USDA-WSARE workshop on “Semiochemicals”, Western Pacific Tropical Research Center, University of Guam, February 16th, 2011.

Outcomes and impacts:

Demonstrable impacts of the project: The semiochemicals trapping techniques have been developed and demonstrated successfully to the agricultural professionals. The individuals learned the techniques with interest.
Demonstrable impacts expected in the future: We expect that the agricultural professionals will disseminate the information on the trapping techniques to the growers in the Marianas. Also, it is expected that the growers will follow and adopt the techniques safe our environment.

Project Outcomes

Project outcomes:

1. Pheromone trapping technique was optimized for the banana root weevil Cosmopolites sordidus, the New Guinea sugarcane weevil, Rhabdoscelus obscurus, the sweetpotato weevils, Cylas formicarius (Coleoptera: Curculionidae).
2. Photos of trapping systems, pest damage symptoms as well as trapping dates were collected and developed into an instruction manual titled SEMIOCHEMICAL-BASED TRAPPING METHOD FOR WEEVIL PESTS ON GUAM.

3. This manual was supplied to the Agricultural Professionals on Guam and the Northern Marianas Islands.

Additionally, three papers published in peer reviewed journals. The copies of the publication are enclosed/attached.

4. New collaborative partnership has been formed with Dr. Robert K. Vander Meer as a collaborator on the new projects.

Recommendations:

Potential Contributions

Ecological pest management through semiochemicals is an area of agricultural production in which Guam’s agriculture professionals need additional training. There is a lack of local knowledge about the role of semiochemicals in pest management. The manual prepared under this project titled SEMIOCHEMICAL-BASED TRAPPING METHOD FOR WEEVIL PESTS ON GUAM distributed to the Ag Professionals, had significantly improved their knowledge on the weevils attacking on various crop plants and trapping techniques. Further training during the workshop conducted on Wednesday November 16th, 2011 covered the relationship between semiochemical-based trapping methods and overall crop production on Guam for important weevil pests. Ag. Professionals have already disseminated the information to the growers and understand the topic well. In fact, the techniques are easy to follow.

Future Recommendations

    1. The following techniques are environmentally friendly control tactics to control the weevil pests. Therefore, these techniques should be popularized among the growers from other regions as well.
    2. 1. We have shown that 40- × 25-cm mahogany brown ground traps baited with pheromone lures and placed in shaded areas of the banana plantation are an efficient tool for catching adult male and female banana borers. Although our experiments were conducted on a small Pacific island, we expect the new trap design to be useful for monitoring and mass trapping of this important pest in larger banana plantations in the mainland and other banana growing areas.
    3. 2. Similarly, the trap design, size, color, and trapping location are important factors affecting the response of New Guinea sugarcane weevil to pheromone-baited traps. In particular, the 40 × 25-cm russet brown ground traps baited with pheromone lures and strapped to the trees are an efficient tool for catching the adults in the field. Indoors, black, but otherwise identical, traps were most effective.
    4. 3. Trap design, size, color, and height are important factors affecting the response of sweetpotato weevils to pheromone-baited traps. In particular, the 13 × 75-cm light red unitraps baited with pheromone lures and installed at 50 cm above the crop canopy is an efficient tool for catching the adults in the field.
    5. All the above findings should be taken into consideration when mass trapping techniques are developed for this important borer pest.
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.