Management of Banana Bunchy Top in Hawaii

Management of Banana Bunchy Top in Hawaii

Summary

The objective of our work is to study the ecology and epidemiology of the virus (Banana bunchy top virus) and its vector (banana aphid, Pentalonia nigronervosa) and to develop management practices for this important disease of banana in Hawaii.

Objectives/Performance Targets

Objectives of the project include:
. better understanding of the banana aphid biology and ecology
. study banana bunchy top virus spread in commercial fields
. determine disease parameters that are important to the development of virus management practices

Accomplishments/Milestones

Sampling plan for banana aphid – We are finalizing data analyses needed for the development of a sampling plan in banana for the banana aphid. The sampling plan will provide growers with information on how to best sample for the presence of banana aphids in their plantations. Over 2,500 plants have been sampled in these surveys.
Aphid distribution within plants – Although it has been widely assumed that the banana aphid occurs preferentially on cigar leaves (new unfurled leaves), our whole-plant surveys have shown that not to be true. We found that the lower leaf bracts of plants more accurately indicate the presence or absence of aphid infestation on individual banana suckers. We found that sampling only the cigar leaf provides false negatives for the presence of aphids on plants in approximately 50% of cases. We are incorporating these results into our sampling plan.
Imidacloprid tests (Provado® efficiency and persistence)- Lab trials examining the efficiency and persistency of Provado® on banana aphid mortality have been completed. This work is important because there are no insecticides currently available to control the banana aphid in Hawaii. We are now analyzing the results.
Survey of BBTV spread in commercial plantations – We have two farmers collaborating with us on this objective. They are providing GPS data on the location of infected plants. Fortunately, these farmers are among the largest growers on Oahu, and they are providing us valuable data that will help us better understand BBTV epidemiology. We have monthly data from these two farms starting January 2005. The spatial and temporal spread of BBTV in these farms will be analyzed after more more data are collected.
Aphid biology – We are conducting experiments to determine aphid fecundity, longevity and length of nymphal stage. Data will be used to develop models for population growth at different temperatures.

Impacts and Contributions/Outcomes

Our preliminary results are informally being passed on to banana growers. We have also given a talk to banana growers earlier this year, and will give another talk highlighting our results and what they mean early next year. Additionaly, we have scheduled a workshop with banana growers for March 2006.

Talks
Wright, M.G., Almeida, R.P.P., Hooks, C.R.R. and Robson, J.D. Aphids and banana bunchy top virus in Hawaii. Invited presentation. 2005 Pacific Entomology Conference, Invasive Species Symposium.
Robson, J.D., Wright, M.G. and Almeida, R.P.P. Biology and ecology of Pentalonia nigronervosa Coq. (Hemiptera: Aphididae) in Hawaii. Presentation at the 2005 Annual Meeting of the Entomological Society of America.
Manuscript
Wright, M.G., Hooks, C.R.R., Robson, J.D. and Almeida, R.P.P. Aphids and banana bunchy top virus in Hawaii. Proceedings of the Hawaiian Entomological Society. In preparation.

Our research has been highlighted by a USDA-CSREES movie. We also collaborated in the design of a BBTV awareness poster.

Collaborators: