1a. Objectives (from AD-416):
The proposed work will provide basic and applied information for the development and transfer of appropriate and environmentally acceptable technologies for control of fruit flies and other invasive species. The major objectives of our projects are: 1) Study population dynamics and pest interactions with their natural enemies, host plants, and other pests in the ecosystem; 2)Identify attractants from host and non-host plants and determine physiological and environmental factors affecting or modulating pest behavior; 3)Improve attractants and trapping systems for surveillance, detection, and control of fruit flies and/or other tropical plant pests of quarantine significance; 4)Assess the efficacy and quality of laboratory-reared insects used in SIT and natural enemies for control of fruit flies and other tropical plant pests of quarantine significance, and determine factors limiting their effectiveness; 5) Develop basic understanding of the oriental fruit fly genome, annotation of functional proteins that regulate development, metabolism, sensory reception and sex determination; and 6)Develop area-wide IPM systems including integration of environmentally friendly replacements for organophosphate chemicals to reduce the economic impact of fruit flies and other tropical plant pests.
1b. Approach (from AD-416):
Test more environmentally acceptable pesticides and compounds for use in control or eradication program for fruit flies. Investigate genomics, biology, and behavior of fruit flies and their parasitoids. Evaluate augmentative parasite releases, mass trapping, male annihilation, sterile fly releases, novel insecticides and food bait sprays as control, suppression, or eradication technologies. Develop new or improved fruit fly strains, lures, attractants, parapheromones, and baits to be used in improved trap detection devices and/or current control systems. Investigate fruit fly and parasitoid olfactory, gustatory, and oviposition aensilla and their electrophysiology. Use genomics, computational biology and area-wide control for fruit flies and other pests.
3. Progress Report:
Continuing progress is being made on development of area-wide technologies for control of fruit flies and other invasive pests such as the Chinese rose beetle locally, nationally, and worldwide. A simulation model and new lure dispensers were developed in Hawaii to help combat continuous California fruit fly invasions. Substantial progress was made on development of a novel RFID fruit fly tagging method. A proposed method for measuring directional dispersal was extensively tested and found to be inadequate. Therefore, there was a shift in focus to model survivorship of wild and sterile Medflies under California climatic conditions in consultation with the California Dept. of Food and Agriculture. A 10-year data set was analyzed for French Polynesia that documented: 1) Displacement of other Bactrocera species by oriental fruit fly, and 2) superiority of F. arisanus as a natural enemy of oriental fruit fly. These studies support classical biological control release of F. arisanus into South America and Africa where species of the B. dorsalis complex have spread. The genome of the oriental fruit fly has been sequenced and refined assembly and annotation is progressing rapidly. Proteonomics studies are progressing on schedule. Finally the use of nighttime illumination to protect plants from defoliation by the Chinese Rose Beetle was demonstrated in field studies and awaits commercialization.
1. Three-Lure (TML, ME, RK = TMR) detection trap against medfly, oriental fruit fly and melon fly shows promise in Hawaii. New outbreaks of invasive fruit flies continue to threaten agriculture world-wide. Establishment of these pests often results in serious economic and environmental consequences associated with quarantine, control, and eradication programs. Early fruit fly detection and eradication in the U.S requires deployment of large numbers of traps baited with the highly attractive male specific lures trimedlure (TML), raspberry ketone (RK), and methyl eugenol (ME) to detect such pests as Medfly, melon fly, and oriental fruit fly, respectively. Currently California deploys 30,000 of these traps for fruit fly detection. In survey trials conducted by ARS scientists (Hilo, Hawaii) and University of California (Riverside) cooperators near Kona, Hawaii captures of medfly, melon fly, and oriental fruit fly with Mallet TMR wafers were equal to those for the standard individual TML, ME, and C-L traps used in Florida and California. A solid Mallet TMR wafer is more convenient to handle, safer, and may be used in place of three individual lure and trap systems, potentially reducing costs of large survey and detection programs in California and Florida, and male annihilation programs in Hawaii. Subsequent tests are now being done in five locations in California.
2. Novel methods for studying fruit fly movement. Little is known about the specific movement activities of fruit flies in the field. ARS scientists in Hilo, Hawaii, develolped a Radio Frequency Identification (RFID) tagging system which has been investigated for the identification of individual tephritid flies. Tests of effects of these tags on flight ability have been conducted and a method for attaching tags to Bactrocera spp. in a way that does not interfere with flight ability has been detailed. Work is ongoing to develop an apparatus that will bring tagged flies close enough to an antenna to be identified without contact. In addition, a novel methodology to measure dispersal direction of wild and colony-reared flies was extensively tested but found to be inadequate. Understanding how flies disperse will allow us to more effectively distribute sterile flies for use in areawide programs.
3. Invasion of French Polynesia by oriental fruit fly and releases of two natural enemies. Over a 10 year period researchers at PBARC along with cooperators from French Polynesia released and established the natural enemy of the oriental fruit fly fopius arisanus. The introduction of oriental fruit fly into French Polynesia resulted in the widespread damage of fruit fly host crops and impacted trade. Researchers at PBARC in Hawaii mass-reared and released large numbers of F. arisanus into French Polynesia aimed for the permanent establishment of this parasitoid against oriental fruit fly. While the introduction of the parasite Fopius arisanus did not result in eradication of oriental fruit fly it significantly reduced populations of this pest on the island and highlighted the value of classical biological control in areas where pests such as fruit flies are established.
4. Genome sequencing of the oriental fruit fly, Bactrocera dorsalis. There is very little genetic information available on pest fruit fly species in the genus Bactrocera. Improving knowledge of Bactrocera at a genetic level can lead to the development of novel approaches towards monitoring and control of this genus. In the past year, ARS scientists in Hilo, Hawaii, have worked to annotate and analyze a draft assembly of the oriental fruit fly. The assembly was supplemented with deep sequencing to increase coverage of the genome, and vastly improve the overall assembly. Using RNA sequencing data, along with gene prediction pipelines, approximately 16,000 potential genes were identified and annotated in the genome. This information will be used as a foundation towards developing new techniques to distinguish species within the B. dorsalis species complex, as well as perform functional genomics experiments towards developing improved methods for mass rearing this insect.
5. Proteomic approach to understanding fruit fly metabolic pathways. Insects such as the oriental fruit fly face many challenges during their lifetimes. To cope with stress insects have developed various behavioral, biochemical, and physiological mechanisms. These responses can be detected at the proteomic and molecular level. ARS scientists in Hilo, Hawaii, have identified differentially expressed proteins/genes specific to certain ages (1-12 days old), sex, and stages (pupa and adult). This information can be used for comparison of differentially expressed proteins when insects encounter stress due to biotic or abiotic factors and information correlated with specific metabolic pathways.
6. Use of nighttime illumination to protect plants from defoliation by Chinese rose beetle. Illumination was used to repel Chinese rose beetle from the leaves of host plants. Chinese rose beetle is a serious defoliator of many crop and ornamental plants. Improved control methods are needed. Researcher at PBARC developed the specific portable LED solar-based light systems that were shown to suppress Chinese rose beetle defoliation by 93% in cacao. Non-chemical means of controlling this pest represents a novel technology that could be used for many plants attacked by this pest.
Mcquate, G.T. 2011. Weathering rate of male sex pheromone of Sweetpotato Weevil, Cylas formicarius elegantulus (Coleoptera: Brentidae), in East Hawaii. Hawaiian Entomological Society Proceedings. 43:1-7.