DEVELOPMENT OF EFFICIENT SEMIOCHEMICAL-BASED CONTROL METHODS FOR WEEVIL PESTS ON GUAM.

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0215448
• Project No.: GUA0561
• Project Start Date: Oct 1, 2008
• Project End Date: Sep 30, 2013

Project Director
Reddy, G.

Recipient Organization
UNIVERSITY OF GUAM UOG STATION
(N/A)
MANGILAO,GU 96913

Performing Department
EXPERIMENT STATION

Non Technical Summary
The chemical ecology laboratory at the University of Guam was originally set up in the college in 2005 as a facility designed to carry out research in chemical ecology and to help other departments in the college. The experiments will be conducted on the (1) To develop a semiochemical-based trapping method to reduce various insect pests with minimal use of insecticides; (2) To be the center for public information on chemical ecology, its products and its potential; (3) To serve the needs of the farmers regarding technology transfer and extension service; (4) To conduct research on chemical ecology in support of the industry; (5) To develop IPM practices with special emphasis on chemical ecology. Moreover, the chemical ecology laboratory is actively working on the development of trap types, size, lures, color, and effect of shade or sunlight on the capture efficiency. We are also in the process of getting import permits for entomopathogens such as Beauveria bassiana and Metarhizium anisopliae from APHIS-USDA.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	0199	1070	100%

Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
0199 - Soil and land, general;

Field Of Science
1070 - Ecology;

Keywords

banana weevil

new guinea sugarcane weevil

sweet potato weevils

west indian sweet potato weevil semiochemicals

trapping

Goals / Objectives
The goal is to continue a well rounded research program to conduct on the development of efficient semiochemical-based control methods for weevil pests on Guam. Work will continue over the next five years. The new project on the Control of the banana borer Cosmopolites sordidus by integrating pheromones and two entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae is recently being submitted to the Western Region SARE program. In the near future, we will work on optimizing semiochemical-based dispensers for the fruit piercing moth, Eudocima fullonia and to develop its trapping method, we will develop an integrated control method for the phytophagous mites on Guam and we will develop a biological control method for the banana skipper, Erionota thraxon (Lepidoptera: Hesperiidae) on Guam.

Project Methods
Methods Three different types of traps ground, ramp, and pitfall will be evaluated. Ground, ramp, and pitfall traps with synthetic pheromone lures will be placed at randomly chosen locations on the ground of banana plantations in the villages of Dededo, Yigo, Agana, and Yona (Guam, USA). Every week, during this experiment and in all the others described below, the banana root borers trapped will be removed and counted. Traps without lure will be used as controls. The efficacies of four different sizes (60 x 40, 50 x 30, 40 X 25, and 30 x 15 cm) of traps will be investigated. Brown, black, gray, yellow, red, white, green, and blue colored vinyl tape will be adhered to all sides of 40 x 25 cm ground traps and will be tested independently (four replicates per color) at the same villages. Color characteristics will be measured with a Konica Minolta CR 410 Chromameter (Minolta Instrument Systems, Ramsey, NJ). For each color the hue angle and chroma will be determined, and the average of three determinations for each color will be recorded. The hue angle indicates the sample color, whereas the chroma provides a measure of the color intensity. The hue angle will be calculated as arc tan (b/a) and chroma as (a x 2 + b x 2)1/2, where a and b are color coordinates. The hue angle is expressed on a 360o grid where 0 o = red, 90o = yellow, 180o = green, and 270o = blue, respectively. Further different shades of effective color will be evaluated. Traps baited with pheromone lures will be placed in the shade and in sunlight at each of the four villages. Each treatment will be replicated four times. Because all the response variables in the experiments will be count variables, a One-way Poisson ANOVA model will be fitted using The GLIMMIX Procedure SAS Version 9.13. The Least Square Means test will be used to make multiple comparisons for significant differences between treatments.

Progress 10/01/08 to 09/30/13

Outputs
OUTPUTS: Research progressed until P.I. resigned in 2012. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Research benefited pest control on Guam.

Publications

• No publications reported this period

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: The sweetpotato weevil, Cylas formicarius (Fabricius) (Coleoptera: Curculionidae), is the most serious pest of sweetpotato around the world. It causes damage in the field and in storage and is of quarantine importance. Because the larval period is spent hidden within vines or tubers and the adults are nocturnal, chemical control is not effective in many cases. In addition, natural enemies are limited, and pheromone-based trapping does not reduce the damage level. In the present study, we evaluated numerous characteristics that affect pheromone-based catches, including trap design, trap size, trap color, and height of the traps. PARTICIPANTS: The Professional Development Program (PDP) of the USDA-WSARE workshop on "Semiochemicals", Western Pacific Tropical Research Center, University of Guam, February 16th, 2011. TARGET AUDIENCES: Reddy, G.V.P. 2011. 59th Annual Meeting of the Entomological Society of America, Reno, NV, November 13-16, 2011. Reddy, G.V.P. 2011. International Symposium on the Two Weevil Pests of Sweetpotato: Strategic Studies for the Eradication of These Pests, Okinawa Prefectural Agricultural Research Center, Okinawa, Japan, 30 November to 1 December, 2011 (Plenary Lectured). Pacific News Center: UOG'S Dr. Reddy to Give Keynote Address at Okinawa Ag Research Center, December 07, 2011. Saipan Tribune: Important int'l collaboration with UOG researcher, December 08, 2011. Eurekalert: Biocontrol of sweetpotato weevils, http://www.eurekalert.org/pub_releases/2011-08/uog-bos080311.php. Pacific News Center: UOG's Dr. Gadi Reddy gets grant to control sweetwotato weevil, August 04th, 2011. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Pherocon unitraps caught significantly higher numbers than ground, funnel water, or delta traps. Medium-sized traps (13 by 17.5 cm) were more efficient than 18, 13, 9, and 7.5 cm traps. In a color-choice test, C. formicarius preferred red traps over gray, brown, blue, white, yellow, black, or red ones; light red was more attractive than other shades of red. Maximum catches were obtained when the traps were set 50 cm above the crop canopy. Light-red unitraps traps with pheromone lures caught significantly more adults than identical traps without pheromone lures. Pheromone-baited light-red unitraps 13 by 17.5 cm installed 50 cm above the crop canopy proved to be the most efficient at catching C. formicarius adults and have the greatest potential for use in trap-and-kill strategies and eradication programs.

Publications

• Reddy, G.V.P. 2012. Recent trends in the olfactory responses of insect natural enemies to plant volatiles, In: Biocommunication of Plants, G. Witzany and F. Baluska (eds.), Springer-Verlag, Germany, pp. 281 to 301.
• Reddy, G. V. P. 2011. Semiochemical-based trapping methods for weevil pests in Guam. Manual. 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: in press.
• 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 to 442.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: The New Guinea sugarcane weevil (Rhabdoscelus obscurus) (Boisduval) (Coleoptera: Curculionidae) is a pest of palm plantations, ornamental nurseries, and sugarcane. Field and laboratory studies have explored the effects of trap characteristics such as design, size, color, visual and olfactory cues, and location on capture of R. obscurus in date palm plantations and ornamental nurseries at five locations (Dededo, Mangilao, Malojloj, Inarajan, and Yigo) on Guam, USA. PARTICIPANTS: The Professional Development Program (PDP) of the USDA-WSARE workshop on "Semiochemicals", Western Pacific Tropical Research Center, University of Guam, February 16th, 2011. TARGET AUDIENCES: Micronesian Palms Face New Threats; Article appeared in "Marianas Variety", August 18, 2009, (http://guam.mvarietynews.com). Reddy, G.V.P. 2010. The 95th Ecological Society of America Annual Meeting, Pittsburgh, PA, August 1-6, 2010. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Ramp and ground traps captured similarly, and both captured significantly more adults than bucket and pitfall traps. For economy and ease of handling, the ground trap was used for all further experiments. Larger ground traps (40 by 25 cm and above) were more efficient than smaller ones (30 by 15 cm) in capturing adults in the field. Of the eight trap colors tested in the field, brown proved most effective, followed by, in order, yellow, red, gray, blue, black, white, and green; russet was more effective than other shades of brown. Mixing paint of the other colors with brown paint did not significantly improve its performance. In contrast, laboratory color-choice tests indicated R. obscurus preferred black traps over those of other colors and showed no preferences among different shades of black. Again, mixing paint of the other colors with black paint did not significantly improve their performance. Russet brown ground traps baited with pheromone lures caught significantly more adults than did identical traps without lures. Traps strapped to trees caught significantly more individuals than traps placed between trees or away from trees. Russet-brown ground traps 40 by 25 cm appeared to be the most effective at catching R. obscurus in the field, whereas otherwise identical black-colored traps were more efficient indoors.

Publications

• Reddy, G. V. P. 2011. Semiochemical-based trapping methods for weevil pests in Guam. Manual. Western Pacific Tropical Research Center, University of Guam, 19p.
• Reddy, G.V.P., and A. Guerrero. 2010. New pheromones and insect control strategies. Vitam. Horm. 83: 493-519.
• 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: in press.

Progress 10/01/08 to 09/30/09

Outputs
OUTPUTS: The banana root borer Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) is a major pest of bananas throughout the world. Chemical control is both undesirable and expensive, where biological control alternatives are limited, and pheromone-based trapping results in low captures. Studies were conducted to determine the pheromone trap efficacy, effect of shade on trap catches and to monitor the population of C. sordidus using pheromones in Guam. In Guam, pheromone traps were used to monitor the population level of C. sordidus. Before monitoring began, two basic studies were carried out, which established that pheromone-baited ramp traps positioned in the shade of the banana crop canopy caught significantly more adults than those placed in sunlight and that ramp traps baited with pheromone lures caught significantly more adults than did identical traps without pheromone lures. Ramp traps baited with pheromone lures were set up at each of 10 locations throughout the island in November 2005. Weekly counts were made of the borers caught by the pheromone traps. PARTICIPANTS: farmers TARGET AUDIENCES: Cooperation with stakeholders My presentation on the banana borers was impressed by many growers and they are excited to use environmental friendly control methods using pheromone traps. I have demonstrated the semiochemical-based trapping method for the growers. I have followed up with the growers on the effectiveness and impact of this control method for the borers pests on Guam. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The data indicated higher population levels (10 per week) in the northern region and low (5 per week) to medium level (5 to 10 week) populations in the southern part of the island. These differences among sites were highly significant. Linear and quadratic effects of rainfall on the number of borers captured were statistically significant, but according to quadratic regression models, the significance was due to differences at just one site. In the second study, several important factors that affect pheromone-based catches, such as trap type, trap dimensions, and color and position of the traps, were optimized. Ground traps were found to be superior to ramp and pitfall traps, and larger traps (40 by 25 cm and above) were more efficient than smaller ones (30 by 15 cm). In a color-choice test, the banana weevil clearly preferred brown traps over yellow, red, gray, blue, black, white, and green; with mahogany being more attractive than other shades of brown. In addition, pheromone baited ground traps positioned in the shade of the canopy caught significantly more adults than those placed in sunlight. Therefore, mahogany-brown ground traps 40 by 25 cm appear to be the most efficient at catching C. sordidus adults and have the greatest potential for use in mass trapping and programs for eradication of this pest.

Publications

• Publications Reddy, G.V.P., Cruz, Z.T., and Guerrero, A. 2009. Development of an efficient pheromone-based trapping method for the banana root borer Cosmopolites sordidus. Journal of Chemical Ecology 35: 111 to 117.
• Reddy, G.V.P., Cruz, Z.T., Naz, F., and Muniappan, R. 2008. A pheromone-based trapping system for monitoring the population of Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae). Journal of Plant Protection Research 48: 295 to 300.
• Presentations Reddy, G. V. P., Cruz, Z. T., and Guerrero, A. Enhanced pheromone-based trapping method for banana weevil, Cosmopolites sordidus (Coleoptera: Curculionidae), International Society of Chemical Ecology 25th Anniversary Meeting, Penn State, State College, Pennsylvania, USA, August 17 to 22, 2008.
• Presentation on the control of banana root borer and New Guinea Sugarcane Weevil using Semiochemical-based trapping method, Farmer Rancher Program, Northern Marianas College, Rota, May, 2008.
• Media coverage of research Pacific News Center, television interview, channel 6 (10 minutes), Banana borer problem in Guam, January 09, 2009. The IPM Practitioner, Volume XXX, Number 7/8: page 13, Banana Weevil Pheromone Traps, July/August, 2008. Pacific Home Garden, Television interview, channel 6 (15 minutes), Control of Invasive Plants in Guam, February 7, 2008. Biological Control: Insects vs. Plants Article appeared in WPTRC 2008 Impact report published by the University of Guam, pp. 9 to 11.