2011 Annual Report
1a.Objectives (from AD-416)
The long-term goal of this project is to increase knowledge of the biology and ecology of the coffee berry borer, and to develop innovative user-friendly, economical, and environmentally acceptable pest management technologies that can be effectively implemented. Research will focus on finding previously unrecorded natural enemies, testing a recently discovered biocontrol agent, determining whether volatiles produced by the berry can serve as attractants or repellents, and determining whether microorganisms play a role in how the insect survives on a food source containing caffeine. Over the next 5 years we will focus on the following objectives:
Objective 1: Discover and evaluate the biological control potential of natural enemies of tropical pests, particularly the coffee berry borer.
• Sub-objective 1.A. Identify new natural enemies of the coffee berry borer through ongoing collaborations, focusing on Kenya, Ethiopia, and Uganda.
• Sub-objective 1.B. Evaluate the biocontrol potential of a recently discovered
coffee berry borer predator.
Objective 2: Develop methods for managing tropical pests (with focus on coffee berry borer) based on knowledge of pest biology (e.g., attractants and repellents, as well as microorganism-mediated mechanisms that allow the insect to thrive on coffee), and host plant-pest interactions, as deduced by studies of host gene expression in response to infestation.
• Sub-objective 2.A. Identify coffee plant volatiles that attract or repel coffee berry borers, using in planta volatile collection techniques.
• Sub-objective 2.B. Identify microorganisms associated with the coffee berry borer that contribute to insect establishment and survival inside the berry, and determine the mechanism of the interaction.
These objectives will integrate various components that we believe are essential to greatly improving our understanding of the beetle and to move the field into a new direction.
1b.Approach (from AD-416)
The project will focus on the discovery and evaluation of the biological control potential and mechanisms of natural enemies of tropical pests, in particular coffee berry borer. Through ongoing collaborations new natural enemies of the coffee Berry borer will be identified and their potential as biological control agents will be evaluated. This portion of the project will focus on natural enemies from Kenya, Ethiopia and Uganda. Further evaluations of the biological control potential of other recently discovered insect predators will be continued. The project will also focus on improving our understanding of the biology of the coffee berry borer. The project will evaluate the insect’s ability to be attracted or repelled by natural coffee volatiles. These plant attractants and/or repellents will be further evaluated for their biological control potentials. Finally microorganisms will be identified from coffee Berry borers. These organisms will be evaluated for their ability to help the insect establish itself and survive inside the coffee berry. The biology of the insect-microorganism-interaction will also be evaluated.
Sampling of coffee berries infested with the coffee berry borer in Kenya and Uganda was conducted in collaboration with scientists at the International Center of Insect Physiology and Ecology in Kenya as part of SCA 58-1275-9-186F. A total of 27 insects (divided into five taxonomically different groups) were collected and will be identified to determine their potential role as natural enemies of the coffee berry borer. Coffee berry borer specimens for research aimed at identifying microbial diversity were obtained from Hawaii, Mexico, and Guatemala. Laboratory experiments indicated that the coffee berry borer might produce a marking pheromone. A new mite species collected from coffee plants in Costa Rica was described in collaboration with scientists at the Systematic Entomology Laboratory.
Possible novel pest management strategy against the coffee berry borer. The coffee berry borer is the most devastating insect pest of coffee in the world, causing more than 500 million U.S. dollars in losses every year, and greatly reducing the quality of coffee available to the coffee industry. Laboratory experiments indicated that as female density increases, the number of progeny produced was reduced. One possible mechanism to explain this finding is the production of a marking pheromone by the female, i.e., a chemical that signals other females that a coffee berry is already occupied and prompts females outside the berry to continue searching for an uninfested berry. ARS researchers at Beltsville, Maryland, and Peoria, Illinois, are conducting experiments aimed at determining whether a marking pheromone can be detected. The elucidation of a marking pheromone could become a widely implemented pest management strategy that could vastly reduce coffee berry borer damage in the field, thereby increasing the availability of high quality coffee for the U.S. coffee industry.
Vega, F.E., Kramer, M.H., Jaramillo, J. 2011. Increasing coffee berry borer (Hypothenemus hampei; Curculionidae: Scolytinae) female density in artificial diet decreases fecundity. Journal of Economic Entomology. 104:87-93.
Beard, J., Ochoa, R., Vega, F.E. 2011. Asca nelsoni sp. nov. (Acari: Mesostigmata: Ascidae), a new mite species from coffee leaf domatia in Costa Rica. Systematic & Applied Acarology Special Publications. 16:7-20.