U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 close



Research
                Research Home
                            National Programs
                            Research Projects
                            Scientific Manuscripts
                            International Engagement
                            Scientific Software/Models
                            Databases and Datasets
                            Office of Scientific Quality Review
            Media
                News & Features
                            Multimedia
                            Briefing Room
                            Down on the Farm
                            Press Room
                            Science in Your Shopping Cart
                            Scientific Discoveries
                            Tellus
                            Under the Microscope
            About ARS
                About ARS Home
                            Staff Directory
                            Labs and Research Centers (Map)
                            Headquarter Offices
                            Organizational Chart
                            Employee Services (REE Employees Only)
                            Office of Outreach, Diversity, and Equal Opportunity
            Work With Us
                Work With Us Home
                            ARS Vacancies at USAJOBS
                            Careers at ARS Information
                            Scientific Collaborations
                            Extramural Agreements
                            1890 Faculty Research Sabbatical ProgramSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Office of International Research Engagement and Cooperation France and Greece EBCL





- Research Highlights
- Allium Leaf Miner Project
- Asian Longhorned Tick
- Bagrada Project
- Cattle Fever Tick Project
- Diamondback Moth Project
- French Broom Project
- Olive Fruit Fly Project
- Tree of Heaven Project
- Sahara Mustard Project
- Viburnum Leaf Beetle Project
- National Programs & Projects
- Quarantine
- Collaborations
- Publications
- Staff
- ARS Careers
- History of EBCL
- Thessaloniki
- Contact
- Sabbatical Information

French Broom Project **Lead scientist: RFH Sforza** **Presentation & context** French broom, *Genista monspessulana* (L.) LAS Johnson (Fabaceae) is a perennial woody shrub, native to the Mediterranean region commonly associated with regeneration in fire-prone environments. *Blooming French broom (Photo by RFH Sforza)* Introduced as an ornamental plant to many parts of the world, French broom is currently a major invader in several countries including the USA and Australia Introduced in the 19th century as an ornamental plant; it is currently invasive in California and Australia. Foreign exploration in the native range (Spain, France, Italy, Greece) by collecting pods, beating tray samples and threshing of leaves, allowed the identification of two major phytophagous arthropod candidates: *Arytinnis hakani*(Longinova, 1972, Hemiptera Psyllidae) and *Lepidapion argentatum* (Gerstaecker, 1854, Col. Brentidae). *Adult of the French broom psyllid (Photo by RFH Sforza)* *Arytinnis hakani is a*sap sucking insect that impacts French broom by intense feeding pressure and the production of high levels of honeydew. The honeydew covers the foliage and causes sooty mold growth. This growth may inhibit photosynthesis. *Lepidapion argentatum* is both a stem gall maker and a seed feeder. ***Mating couple of Lepidapion argentatum (Photo by RFH Sforza)* **Research components** First, our research is focused on biology and specificity of the weevil *Lepidapion argentatum.*The development time of *L. argentatum* in stem galls ranged from 34 to 40 days at mean 23.67 ± 2.43°C. The double ability of *L. argentatum* to develop in stems and pods appears not to have been recorded in Coleoptera and rare in other phytophagous insects. That makes it a promising candidate. The impact on the reproduction of French broom was studied in Southern France and revealed that it could effectively reduce the number of viable seeds by 18.8%, but also increased the number of aborted seeds by 10% within the attacked pods. To evaluate the specificity of *L. argentatum*, choice and no-choice tests were performed in 2012 and 2015 on a total of 36 non-target closely related species. Results revealed the presence of galls and larvae in the stems of seven species, including two endemic Californian lupines, i.e. *Lupinus arboreus blue* and *L. chamissonis*. In the future, new tests will be conducted to determine if *L. argentatum* is able to complete its entire development lifecycle on the non-target species where galls have previously been observed. Second, an important aspect of biocontrol research is to determine the potential of an agent to distribute and not attack native vegetation. Thus, EBCL researchers (Sforza & Desurmont) are conducting an open field test to evaluate the movement and effectiveness of the French broom psyllid *Arytinnis hakani* under more natural conditions. Two concentric circles with a radius of five and 10 meters were constructed and plant species belonging to the lupine group and French broom control plants randomly placed along the two perimeters in an open field test. At the centre of the two circles, hundreds of psyllids of all life stages were released in spring 2021 & 2022. The spread of individuals on the lupines and the French broom control plants was quantified. The data are currently in the process of being analysed. The overall purpose of studying these two biocontrol candidates is to prepare a petition to release in North America. **S****tudents involved** Tabary (Master1, 2019), E. Kerdellant (Master2, 2015), T. Bernard (Master2, 2012) **Recent publications** Kerdellant et al. 2021 Insects Kerdellant et al. 2019 Ent. Exp & Applicata


Return to top


Research
                            Media
                            About ARS
                            Work With Us


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov