Exploration, Genetic Characterization, and Host Range Testing of Parasitoids for Biocontrol of the Erythrina Gall Wasp, Quadrastichus erythr

EXPLORATION, GENETIC CHARACTERIZATION, AND HOST RANGE TESTING OF PARASITOIDS FOR BIOCONTROL OF THE ERYTHRINA GALL WASP, QUADRASTICHUS ERYTHR

Sponsoring Institution

National Institute of Food and Agriculture

Project Status

COMPLETE

Funding Source

SPECIAL GRANT

Reporting Frequency

Annual

Accession No.

0214950

Grant No.

2008-34135-19384

Cumulative Award Amt.

(N/A)

Proposal No.

2008-03851

Multistate No.

(N/A)

Project Start Date

Sep 1, 2008

Project End Date

Aug 31, 2011

Grant Year

2008

Program Code

[AH]- Tropical & Subtropical Research/T STAR

Recipient Organization
UNIV OF HAWAII
3190 MAILE WAY
HONOLULU,HI 96822

Performing Department
PLANT & ENVIRONMENTAL PROTECTION SCIENCES

Non Technical Summary
The newly invasive Erythrina gall wasp (Quadrastichus erythrinae) has swept over and devastated both endemic and ornamental Erythrina (coral trees, wiliwili) trees throughout the islands of Hawaii. The wasp populations reach such high densities that virtually every leaf and shoot on the trees is deformed and seed production is reduced. Such intense infestations are likely to eliminate the trees, causing severe disruption to native Hawaiian ecosystems and costing millions of dollars in ornamental tree and windbreak replacement throughout the State. Furthermore, Coral trees (Erythirina spp.) are extensively planted on the US mainland, especially in southern California and the gall wasp is likely to arrive there shortly. Therefore, this is an emergency situation; Erythrina trees have not been able to sustain leaves for several months and may not survive another year of such infestation. We propose to actively evaluate as many potential biological control agents for the gall wasp as possible, working in close cooperation with the State Department of Agriculture. We will simultaneously use DNA sequence to identify the source population of the Hawaiian infestation and direct our search for biological control agents accordingly. Further, DNA sequence will be very helpful in assuring conspecific identity in these minute gall wasps, and any parasitoids we are evaluating. Theoretically, this work will allow us to evaluate possible new associations between parasitoids and the gall wasps and to monitor long-term trends and effectiveness. We will therefore determine the origin of the invasive wasps; conduct exploration for potential natural enemies of Q. erythrinae; introduce potential natural enemies into quarantine; assess their effectiveness and non-target potential (in collaboration with the Hawai'i Department of Agriculture); and make releases of appropriate natural enemies for the control of the gall wasps. Effectiveness of the wasp will be monitored following release. The quantification of the effect of the introduced biological control agent on the Erythrina gall wasp has the potential to contribute a landmark study of the effects of a biological control agent on a severely invasive species.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
211	0640	1130	50%
215	0640	1130	50%

Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants; 215 - Biological Control of Pests Affecting Plants;

Subject Of Investigation
0640 - Tropical forests;

Field Of Science
1130 - Entomology and acarology;

Keywords

Goals / Objectives
Objectives: 1. Search for, identify, taxonomically describe (using molecular and morphological characters), and import natural enemy species of Quadrastichus to Hawaii. 2. Conduct phylo-geographic genetic analyses of Quadrastichus spp. to determine origin of the Hawaii infestation. 3. Conduct preliminary studies on the bionomics and host range of the natural enemies in their native environments (Africa), with reference to various Erythrina species. 4. Determine the bionomics and the host range of imported parasitoids in quarantine in Hawaii, with reference to both target and non-target species. 5. Quantify population and infestation levels of Erythrina gall wasps on several Hawaiian Islands, to be used as a reference point against which to measure parasitoid impact following field release and establishment; conduct post-release assessment of effectiveness of natural enemies. Deliverable products: 1. Identification of one or more potential candidate biocontrol agents from West Africa, East Africa and South Africa; 2. Collection of data on parasitoid host range and ecology; 3. Comprehensive documentation concerning the safety of potential EGW natural enemies and efficacy in the suppression of the pest in Hawaii 4. Release from the quarantine of efficient EGW natural enemies 5. Measure impact of released natural enemies on gall insect populations in Hawaii.

Project Methods
General collection of specimens and exploration Phylogeography reconstruction Laboratory screening for effectiveness of potential biological control agents Pre- and post release assessment

Progress 09/01/08 to 08/31/11

Outputs
OUTPUTS: Successful release and establishment statewide of the biological control agent, Eurytoma erythrinae. Monitored effect of biological control agent on the pest insect statewide. Demonstrated effectiveness in all areas released, including release sites where establishment was initially slow. Documented improved Erythrina tree health attributable directly to release of biological control agents. Presentations: Kaufman, L.V., Yalemar, J., Wright, M.G., Messing, R.H., Rubinoff, D. 2011. Pre- and post release monitoring of Eurytoma erythrinae and gall wasp populations on exotic Erythrina species in Hawaii. Paper presented at Pacific Branch ESA, March 29, 2011, Waikaloa, Hawaii. PARTICIPANTS: Hawaii Department of Agriculture TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Significant improvements in viability of endemic and exotic ornamental Erythrina species statewide. Demonstrated effectiveness and environmental compatibility of biological control. Contributed to conservation of an endemic Hawaiian species.

Publications

No publications reported this period

Progress 09/01/09 to 08/31/10

Outputs
OUTPUTS: The Erythrina gall wasp, Quadrastichus erythrinae Kim (Hymenoptera: Eulophidae), was accidently introduced to Hawaii in 2005 and quickly spread throughout the state infesting many species of Erythrina, including all stands of the endemic Erythrina sandwicensis to varying degrees. Soon after the gall wasp arrival, the Hawaii Department of Agriculture and the University of Hawaii initiated a biological control program. In November 2008 Eurytoma erythrinae (Hymenoptera: Eulophidae) was approved for released. Three months after the official release, E. erythrinae was recovered at some sites and it is now established throughout the state. Results from post-release monitoring indicate that E. erythrinae is successfully controlling gall wasp populations at most sites, and surviving wiliwili trees are recovering from gall wasp damage. Post release monitoring continues in order to determine the impact that E. erythrinae will have on the species' long-term viability. PARTICIPANTS: Hawaii Department of Agriculture Hawaii Department of Land and Natural Resources TARGET AUDIENCES: Landscape contractors, agricultural managers, conservation organizations. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
Successful establishment of parasitoid. Quantification of impacts on pest. Reduced gall insect impacts on Erythrina species.

Publications

Leyla V. Kaufman, Mark G. Wright, Russell H. Messing, Daniel Rubinoff and Julianna Yalemar. 2010. Rapid global invasion by Quadrastichus erythrinae (Eulophidae), the Erythrina gall wasp and the Hawaii biological control success. Paper presented at Biocontrol for Nature meeting, Mass.

Progress 09/01/08 to 08/31/09

Outputs
OUTPUTS: Made releases of Eurtoma erythrinae statewide. Monitored establishment. Measure impacts on tree health and gall insect populations. PARTICIPANTS: Hawaii Department of Agriculture Hawaii Department of Land and Natural Resources TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Added quantification of impact of biological control agents on tree health as an extra research objective.

Impacts
Successful establishment of biological control agent. Evident successful protection of Eythrina trees from Erythrina gall wasp. Resurgence of foliage on indigenous Erythrina trees in areas previously hard-hit by gall wasps.

Publications

Rubinoff, D., Holland, B.S., Shibata, A., Messing, R.H. & Wright, M.G. 2009. Rapid invasion despite extremely low genetic diversity in the invasive Erythrina Gall Wasp (Quadrastichus erythrinae Kim, Delvare and La Salle 2004). Pacific Science 64: 23-31.